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TM 11-6625-2780-14&P

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1. 2 4 8 E 128 256 Metz 64 128 MHz 32 64 MHZ EECL ECL BUFFER CONVERTER suas gt 256 512 MHz BUFFER 4 x x v 89 v B3 y m 08 B8 B B6 BS 5 7 U 5 V 3 L MODULATOR PREAMPL 2 gt eS LB MODULATOR QUTPUT AMPL OUTPUT ATTEN SCHMITT omen TRIGGER BUFFER para um NOTES 0 51 Bl 1 2 2 4 4 8 B4 8 16 85 16 32 B6 32 64 87 64 128 88 128 256 89 256 512 810 512 1024 Bll HB UPPER FREQUENCY RANGE OF BANDS 5 11 LB LOWER FREQUENCY RANGE OF BANDS B5711 DIAGRAM SHOWN IN 0 5 1 MHz RANGE B1 GNO LOGICAL HIGH OPEN OR NEGATIVE LOGICAL LOW FREQUENCY RANGES NOMINAL Figure 8 41 Simplified Logic Diagram of the F ter Divider Assembly SERVICE SHEET 11 PRINCIPLES OF OPERATION RF Dividers A10A2 The A10A2 RF Divider Assembly frequencies divides the 256 512 MHz signal from the RF oscillator to oblain lower output frequencies The overall operation of the A10 Divider Filter Assembly is described on Service Sheet 10 Refer also to Figure 8 41 for a simptied logic diagram of the RF Dividers and Filters On the two highest frequency bands 256 512 MHzand external doubier the dividers are bypassed On the other hands the signal from the oscillator is amplified and limited by buffe
2. HP 8003A Power HP 435A Power Sensor per Ace ae ee ie de HP 8482A Initial Test Conditions To test A26A2 AM Offset and Pulse Switching Assembly remove top cover see Service Sheet G for removal procedure remove A26 AM AGC and RF Amplifier Assembly casting top cover and remove A26A2 and extend for service see Service Sheet F for procedure To test 2601 Output Amplifier and A26A1 AGC Detector Assembly also remove bottom cover see Service Sheet G for removal procedure and remove A26 casting bottom cover see Service Sheet F for procedure Connect the pulse generator to AM INPUT Set the pulse generator for a repetition rate of 20 Hz a pulse width of 25 ms and an amplitude of IV Initial Control Settings Meter Function 0 00000008 LEVEL COUNTER MODE EXPAND Off LOCK Mok eve Off Source uci A ao me eoe Gok oe ANTE Sena th Natal Maes ea OFF Fully cw MODULATION FREQUENCY 1 kHz FM OFF 8 16 MHz FREQUENCY TUNE 7 20 MHz OUTPUT LEVEL 16dBm RE ON OFF UMS WP du e ON AGC Amplifiers and Amplitude Modulator A26 A26A3 A26A4 SERVICE SHEET 12 Service Model 8640B Option 004 SERVICE SHEET 13 Cont d N
3. 13 13 BOR ON 10 TABLE 6 3 REPLACEABLE PARTS DESCRIPTION DIODE ZNR 5 62V 5 DO 7 PD 4W DIODE ZNR 10V 5 DO 7 PD 4W TC 06 RF OSCILLATOR ASSY NRFR RESTORED 08640 60099 REQUIRES EXCHANGE NSR PART OF A3 NSR PART OF A3 NSR PART OF A3MP10 RETAINER RING 125 DIA CAD PLT STL RETAINER RING 438 DIA CAD PLT STL GEAR SPUR GEAR SPUR GASKET COVER FINE TUNE BUSHING POT RFI PLUG BE CU IAU PL 173 OD 18 L BUSHING POT CAP TRANSISTOR OSCILLATOR FINE TUNE ASSY SCREW MACH 4 40 PAN HD POZI REFC SST 300 WASHER LK HLCL NO 4 115 IN ID 226 IN RFI ROUND STRIP NI ALY 06 OD RETAINER RING 438 DIA CAD PLT STL SCREW SET 4 40 SMALL CUP PT HEX REC ALY GEAR SPUR SCREW SET 4 40 SMALL CUP PT HEX REC ALY WASHER LK INTL T 377 IN ID 507 IN OD SCREW SET 4 40 SMALL CUP PT HEX REC ALY WASHER LK INTL T 377 IN ID 507 IN OD SCREW SET 4 40 SMALL CUP PT HEX REC ALY SCREW MACH 8 32 PAN HD POZI REC SST 300 WASHER FL MTLC NO 8 172 IN ID 375 UB WASHER LK HLCL NO 8 168 IN ID 31 IN SHAFT MOD FINE TUNE RETAINER RING 125 DIA CAD PLT STL TRANSISTOR RESISTOR VAR 10K 20 C RESISTOR VAR PREC 1K 3 WW NOTE WHEN REPLACING A3R1 OR R2 ALSO RE PLACE BUSHING A3MP6 OR MP8 AND LOCK WASHER A3MP18 OR MP20 MSR PART OF A3 FILTER BUFFER AMPLIFIER ASSY NRFR CAPACITOR FXD 5500PF 0 200WVDC CER CAPACITOR FXD 5500PF 0 200WVDC CER CAPACITOR FXD 5500PF 0 200WVDC CER
4. After frequency lt 15 lt 1 min change after After band change relocking to be within After 1 min in RF 0 1 ppm of OFF Mode steady state frequency 10 min SPECTRAL PURITY Harmonics on IV 10 dBm output range and below Residual AM Averaged rms gt 35 dB below fundamental of 0 5 to 128 MHz Post detection Noise Bandwidth gt 30 dB below fundamental of 128 to 512 MHz Subharmonic and Nonharmonic Spurious excluding frequencies within 15 kHz of carrier whose effects are specified in Residual AM and FM gt 100 dB below carrier Residual FM Averaged rms Noise Averaged rms noise level below carrier stated CW and up to Up to maxi in a 1 Hz bandwidth 1 8 maximum mum allowable SSB Phase Noise at 20 kHz offset from carrier See allowable peak peak and 1 3 deviation deviation 256 MHz to 512 MHz 2130 dB from 230 to Post det ctiori 300 Hz 300 Hz 20 Hz t 450 MHz increasing linearly to gt 122 dB down io a io at 550 MHz 0 5 MHz to 256 MHz Decreases approximately 3 REA 3 kHz 15 kHz 6 dB for each divided frequency range until it 230 to 550 MHz lt 15 Hz lt 15 Hz lt 30HZ reaches SSB Broadband Noise Floor of gt 140 dB Note Residual FM decreases by approximately 1 2 for each divided frequency range until limited by broad band noise floor This limit for 300 Hz to 3 kHz is SSB Broadband Noise Floor greater than 1 MHz offset f
5. 13 dBm OUTPUT LEVEL Vernier RF ON OFF 2 Using the filter kit prepare a 1 MHz Butterworth low pass filter and install it in the discriminator 3 Set discriminator s range to 10 MHz and sensitivity to IV 4 Set spectrum analyzer s resolution bandwidth to 100 Hz and its center frequency controls to a 0 to 5 kHz span Set the display for 10 dB per division 4 80 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 44 FM DISTORTION TEST Cont d 5 Use generators PEAK DEVIATION vernier to set 80 kHz of peak deviation as read on panel meter Use analyzer s display reference level controls to set the demodulated 1 kHz signal to the top reference graticule line on the display 6 Note the level of the 1 kHz signal s harmonics 2 kHz 3 kHz etc For less than 3 distortion they should be more than 30 5 dB below the reference graticule line Maximum Deviation 30 5 dB 7 Set generators PEAK DEVIATION switch to 10 kHz If necessary use generators PEAK DEVIATION vernier to set 10 kHz of peak deviation use analyzer s display reference level controls to set the demodulated 1 kHz signal to the reference graticule line 8 For less than 1 distortion the 1 kHz signal s harmonics should be more than 40 dB below the reference graticule line 1 8 Maximum Deviation 40 dB 4 45 FM SENSITIVITY AND ACCURACY TEST SPECIFICATION Externall FM Sens
6. OUTPUT LEVEL 10 dB SWITCH TO 10 dBm NON PERIODIC PULSE PREAMPLIFIER OUTPUT LEVEL DEMODU ve SWITCHES 16 dBm AA METER ANNUNCIATOR DRIVE ASSY EE MODULATION FREQUENCY MODULATION WITH OFFSET METER DRIVE AMPLIFIER 5 PAD Al 10208 OUTPUT LEVEL ASSY P O A18 10 dB OUTPUT LEVEL ASSY t 1 POSITIVE 7 Al Ai nae AUTO RANGE OUTPUT OUTPUT LEVEL LEVEL ou SWITCH 2 2 AM OFFSET AND PULSE SWITCHING ASSY COMPARATOR AMPLIFIER GAIN LOGIC OUTPUT LEVEL SWITCHES 44 2 IN REDUCE PEAK POWER ON THEN OFF AMPLIFIER METER AMPLIFIER OVERLOAD DETECTOR METER AG AMNUNCIATOR t HM LAMP DRIVE LOGIC 17 3 Figure 8 20 AM AGC Circuits and Output Amplifier Block Diagram 6099 AM AGC Circuits and Output Amplifier Troubleshooting 4 SERVICE SHEET 3 Service SERVICE SHEET 4 PRINCIPLES OF OPERATION Internal Count Mode When the internal count mode is selected the 256 512 MHz signal from the Frequent y Counter Buffer Amplifier Service Sheet 2 is first divided by 64 and then is counted by the Up Down Counter used in the count up mode An ECL to TTL Translator shifts the logic levels of the 64 Divider to be compatible with the counter
7. COUNTER MODE EXPAND Off LOCK Off Source AM mode Ee olde we ode 2 HORE Modulation Fully ew FM TEL We lm we Ae 2 ORE RANGE 2 4 MHz FREQUENCY TUNE 7 3MHz OUTPUT LEVEL Switches 13 dBm OUTPUT LEVEL Vernier RF ONOFF ON 2 Let the equipment warm up for two hours to minimize drift of the spectrum analyzer detector output 3 Set the calibrated step attenuator to 10 dB 4 Set the spectrum analyzer center frequency to 3 MHz frequency span to 200 kHz per division resolution bandwidth to 300 kHz input attenuation to 20 dB and vertical scale to linear Set the frequency span to zero and tune the spectrum analyzer to peak the trace NOTE Throughout this test check that the signal is peaked in the center of the analyzer s passband 5 Set the digital voltmeter to read mVdc with maximum filtering Adjust the spectrum analyzer s vertical sensitivity for a digital voltmeter reading of 200 0 mVdc 6 Set the calibrated step attenuator to 0 dB and note the digital voltmeter reading Digital Voltmeter reading 7 Set the calibrated step attenuator to 20 dB and note the digital voltmeter reading 4 66 Digital Voltmeter reading mVdc mVdc M
8. P O A9A2 INTERCONNECT ASSY Ames METER ATTENUATOR a mum SCALE ANNUNC PEAK DEVIATION y ph i P O S1 10 kHz o 10 kHz 20 kHz J o 20 kHz 40 kHz o 40 kHz 80 kHz 80 kHz L 160 kHz 160 kHz 320 kHz o 320 kHz 640 kHz 640 kHz 1 28 MHz 1 28 MHz 2 56 MHz 5 12 MHz METER ATTENUATOR LAMP CONTROL 5 D 3 gt a gt e lt e T 7 e 2 lt amp e lt amp 5 lt e lt e a gt a lt amp lt a P O A9A2 INTERCONNECT 601256 gt lt 5 E ud 3 lt 5 lt amp a 5 a lt 2e a 7 48 08640 90073 P O Figure 8 33 Over Deviation Detector and Meter Control Circuits Schematic Diagram P O Change 7 614 P O A9 PEAK DEVIATION AND RANGE SWITCH ASSEMBLY REFERENCE DESIGNATIONS WITHIN OUTLINED ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER e g OF ASSEMBLY Al 5 AIRI DESIGNATIONS OF OTHER COMPONENTS ARE aE a TA COMPLETE AS SHOWN P O Figure 8 53 AM Interconnections and RF ON OFF Switch Schematic Diagram P O Change 7 pauo3 39NVH 700 uondo gor98 IPPON 2006 07980 Model 8640B Option 004 08640 90073 CHANGE 7 Cont d P O A9 PEAK DEVIATION AND RANGE SWITCH ASSEMBLY ASA
9. HP 8640A Mixer 105 10dB Step Attenuator HP 355D 40 dB Amplifier HP 08640 60506 Oscilloscope HP 180A 1801A 1820C Spectrum Analyzer HP 141T 8552B 8556A Noise Phase Lock Circuit HP 08640 60504 PROCEDURE 1 Connect equipment as shown ip Figure 4 6 after setting test Signal Generator s controls as follows 4 26 Meter Function LEVEL COUNTER MODE EXPAND off LOCK 2 amp we xe aw of can FM om ke PEAK Deviation 243 i 5 kHz PEAK DEVIATION Vernier Filly CW RANGE 256 512 MHz FREQUENCY TUNE i i1 i i o oi ox 550 MHz OUTPUT LEVEL switches 7 dBm OUTPUT LEVEL Vernier RF ON OFF ON Set analyzer s input level control to 40 dBm resolution bandwidth to 1 kHz dBm dBV control to dBm 50 ohm span width per division scan width to 5 kHz and center frequency controls to 20 kHz Set display reference level to 40 dBm at 10 dB per division Using analyzer s 20 kHz markers measure and note 20 kHz on the display Set oscilloscope s volts div control to 0 02 and time div control to 50 ps set the input to measure dc Set 10 dB step attenuator to 80 dB Set 40
10. por p 2 id sl ANNUNCIATOR a 5 EN EUA LAMP ASSY E rd 1 1 8 AE kfz o o 96 kHz od 7 Rao 9 312 GND a a 9 9 128 o7 1 28 SCALE L T R31 2 56 Mz 21021756 Mir lt 6 17 9 9 i X ER ANNUNCIATOR lt 925 17 i Figure 8 33 Over Deviation Detector and Meter Control Circuits Schematic Diagram 8 33 Figure 8 32 P O A7 FM Shaping Assembly Component Locations Over Deviation Detector and Meter Control Circuits A6 A7 A9 SERVICE SHEET 8 Service SERVICE SHEET 9 PRINCIPLES OF OPERATION General When either the AM or FM modulation select switch is set to INT the Modulation Oscillator is enabled The oscillator feeds a 1000 or 400 Hz signal selected by the MODULATION FRE QUENCY switch into the AM or FM modulator circuits and to the AM or FM front panel OUTPUT ports The fixed frequency modulation oscillator shown on this Service Sheet is the standard oscillator supplied with the generator Modulation Oscillator Al 1 Amplifier Ul is the gain block A frequency selective bridged tee network forms negative feedback path for 01 This network is a notch filter with zero phase shift at the minimum of the notch The frequency of oscillation is determined by the network Cl C2 and either and R2 or R3 and R4 The positive feedback pat
11. Figure 8 12 Basic Decade Counter Scaler 8 9 Service Model 8640B Option 004 PROGRAMMABLE COUNTER T TRIGGER CE COUNT ENABLE LD LOAD Dp DATA INPUT CLR MASTER CLEAR Qp DATA OUTPUT TC TERMINAL COUNT 9 COUNT AND CE BINARY STATE DIAGRAM Figure 8 13 Programmable Counter 8 10 Model 8640B Option 004 8 63 If the counter has a count enable CE input it must be held high for successive T inputs to cause the counter to increment or count When the counter reaches the nine count a high at CE causes a terminal count or carry in this case a high to appear at the carry TC output 8 64 A low on the clear CLR input clears all outputs to a low independent of any other input conditions 8 65 Programmable Up Down Counter pro grammable up down counter shown in 8 14 operates similarly to the programmable counter which could be called a programmable up counter The up down counter has two trigger or clock inputs count up CU and count down CD A low to high transition of either count input while the other count input is held high incre ments the count by one If both CU and CD are high the count does not increment 8 66 The counter s outputs QA QB Qc and QD can be set to any count from zero to fifteen by entering the count at the data inputs Da DB Dc and Dp while the load input LD is held low Then the count can be incremented up or down
12. Fully cw RANGE 256 512 MHz FREQUENCY TUNE a 360 MHz OUTPUT LEVEL Switches 7 dBm OUTPUT LEVEL Vernier RF ON OFF s NOTE If it is desired to optimize FM linearity at a frequency other than mid band proceed as follows a Set RANGE and FREQUENCY TUNE to the desired frequency b Set RANGE to 256 512 MHz c Set the reference signal generator 5 MHz below the test generator s output frequency 2 Set reference signal generator for 355 MHz CW signal at 7 dBm 3 Calibrate the discriminator prepare a 25 kHz filter from the filter kit and install it in the discriminator Set FM linearity circuits output switch to ref Adjust variable phase generator s variable phase output s amplitude and the oscilloscope s horizontal gain for full screen deflection on the display Adjust reference signal generator for 5 MHz on the discriminator 4 Set variable phase generator s reference phase output for a 1 kHz signal at an amplitude that gives a 2 56 MHz peak deviation indication on the Signal Generator s panel meter Set linearity circuit s voltage divider switch to 100 Adjust generator s variable phase output s phase for a straight line on the display as shown in Figure 5 12 Adjust oscilloscope s vertical gain for 1 division at edge of display 5 37 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 41 FM LI
13. HP 01802211 Reference Signal Generator HP 8640A Mixer HP 10514A 3 kHz Low Pass Filter LPF CIR Q TEL 5 Pole 15 kHz Low Pass Filter ie CIR Q TEL 7 Pole 50 Ohm Load 2 5 5 HP 11593A PROCEDURE 1 Connect equipment as shown ih Figure 4 9 after setting test Signal Generator s controls as follows Meter Function LEVEL COUNTER MODE EXPAND 55 d oae m e oum dv wu LOCK s s e a Off Source NT 4 32 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 24 RESIDUAL FM TEST Cent d PEAK DEVIATION 320kHz PEAK DEVIATION Vernier Fully cw RANGE 256 512 MHz FREQUENCY TUNE i io oio i X 500 MHz OUTPUT LEVEL Switches 7 dBm OUTPUT LEVEL Vernier 505 205 Cae Wc 2 Install shorting board in discriminator and calibrate it for 1 Vdc at the output jack for a full scale meter reading Remove shorting board prepare a 20 kHz Butterworth low pass filter from the filter kit and install the filter in the discriminator 3 Set reference signal generator for a 500 10 MHz CW signal at 13 dBm 4 Connect discriminator to mixer Set discriminator s range to 100 kHz and sensitivity to 0 01 Vrrns Fine tune either generator for a full scale meter reading on the d
14. OF ASSEMBLY 15 AIRI DESIGHATIOHS OF OTHER COMPOWENTS ARE COMPLETE 5 SHOWER aa 9 11 13 Figure Ng Frequency Modulation Oscillator Option 001 Schematic Diagram 2 47 SERVICE SHEET 10 PRINCIPLES OF OPERATION Divider Filter Assembly General The A10 Divider Filter Assembly frequency divides and filters the signal from the RF oscillator The divider network see Figure consists of a chain of nine binary dividers 42 The output is taken either from the RF oscillator buffer or from an OR gate at the output of one of the dividers depending on the frequency range selected all other divider output gates are disabled and also the divider immediately following the output divider The output gates are transformer coupled out and drive a power amplifier which drives the modulator The modulator con trols the signal level and adds AM The output from the dividers and the modulator is approx imately a square wave The low pass filters remove the signal s harmonics On the four lowest frequency bands the square wave output is quite symmetrical 1 second harmonics are well suppressed In the lower portion of these bands the filters suppress only the third harmonic and higher On higher frequency bands the divider output is more asymmetri cal and more second harmonic is present Each of these bands has two filters In the lower portion of these bands the first filter s s
15. Rd R5 1 Ki 3160 3160 Plo 5N 52 I A REFERENCE GESIGNATIONS PREFIX po We CRI1 5 1 2 P O 51 DELETED ABAIRZ ABAIR3 NOTES SEE BACKDATI NG TABI 7 LAND 7 2 REFERENCE DESIGNATIONS WITHIN QUTLIMED oe ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION OF fue Cortes lt COMPLETE AS SHOWN ASA1U3 4 TOP VIEW 2 TOP VIEW a 8 16 h 1 7 1 CIRCUIT BOARD TOP VIEW n 8 ooo GG z 1 7 ABA1 COUNTER SCA LER OPTIC die Figure 8 62 Counter RF Scaler Schematic Diagram SERVICE SHEET 19 PRINCIPLES OF OPERATION General The A8A3 Time Base Assembly contains the internal counter time base reference and circuits that frequency divide the time base reference down to the period required to gate the counter for a particular selection of frequency range and counter mode Additional circuits adjust the duty cycle of the time base for phase lock and non phase lock modes and decode the decimal point to the counter display All counter assembly inputs are heavily filtered to prevent RF leakage Time Base Reference Crystal Oscillator A8A3 The internal Time Base Reference
16. ii n 20m lt 20 ms CIRCUIT BOARD 10 gt TOP VIEW I y 10 6 i 1 00000 1 2 90000 ca 5 9 1 boa amee m SPEED REGULATOR aa T t 619 147 6 34V 6 1 1 t i i i t 1 t 1 Service REFERENCE DESIGNATIONS NOTES 1 SHOWN BELOW 15 AN ELECTRICAL APPROXIMATION OF THE VOLTAGE REGULATOR 9 T SEE BACKDATING TABLES 7 1 AND 7 2 Al8U1 TOP VIEW 110 23 A18 A18 Figure 8 76 5 2V Regulator and Fan Circuits Schematic Diagram 8 65 8 66 Model 8640B Option 004 Service TO Q5 A17 POWER SUPPLY MOTHER BOARD ASSY 08640 60001 Sec REFERENCE DESIGNATIONS 9 TO 5 2V REGULATOR AND FAN DRIVER 5 2V AND 44 6V REGULATOR 940 intext P O XAI7 XA XAI8 XA20 REF 18 20 15 RISER ASSY XA22 1234 5678291011 24240 DB M 1 6789 WN 15 08640 60018 dii XA26A5 l gt ODD RANGE CODE 3 5 2V SUPPLY pu 1 gt wo 22 T HH meo o vaj I AV SUPPLY Lies 1 Rum E 11 NEC ADR 1 aa ae uin NON FUNCTIONING WM t 1 13 gt 20V SUPPLY 7 559 22 NC 5 1 16 1 RF ON OFF BENIN 18 20V SUPPLY ERE TI ME EN ONE R
17. 13 dBm OUTPUT LEVEL Vernier CAL RE ON OEE 252255499 5 4 de wx 40 ON 4 78 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 43 FM 3 dB BANDWIDTH TEST Cont d 2 Prepare a 1 MHz Butterworth low pass filter and install it in the discriminator Set discriminator s range to 10 MHz and input sensitivity y to 1 V 3 Set Signal Generator s FM switch to AC Set spectrum analyzer s resolution bandwidth to 3 kHz and its center frequency controls to 1 kHz with no sweep Set analyzer s tracking generator output level for 80 kHz peak deviation and read on generator s panel meter Set the analyzer s frequency controls for a O to 250 kHz sweep Set the analyzer s display for 2 dB per division adjust the display reference level controls to display the demodulated sweep 4 Measure the sweep on the analyzer s display Total amplitude variation from 20 Hz to 250 kHz should be lt 3 dB l 3 dB NOTE If the FM discriminator s incidental AM rejection is insufficient the generator could appear to be out of specification To check the discriminator note analyzer s reading in dBm set generator s AM switch to AC and connect analyzer s tracking generator output to AM INPUT Set MODULATION for 10 as read on panel meter The analyzer should read 230 dB below the reading noted above If it does not adjust discriminator sensitivity and trigger level or generator s OUTPUT LEVEL controls until i
18. IV at TP8 BW Check A26A2Q8 Q9 and associated circuitry Same signal level on both sides of C4 and C5 INT Set RANGE to Signal level differs across Check C5 Q7 Q9 and 4 8 MHz C i e no signal at Q7 e associated circuitry Set RANGE to Signal level differs across Check C4 Q6 VR2 and 1 2 MHz 1 no signal at Q6 e associated circuitry Set AM to PULSE Signal level differs across Check Q5 Q7 Q8 VR1 C6 i e no signal at Q5 e and associated circuitry Model 8640B Option 004 PIO A26 AMVAGC AND RE AMPLIFIER ASSY 080 608 4 e M o m Aem DETECTOR BUFFER AMPLIFIER amm GAIN 1 Nip yu s m BW CONTROL wa RF FROM RF FILTERS 10 or VRZ 6 ev u o ee o o Figure 8 47 A26A1 Power Amplifier and AGC Detector Assembly Component Locations _ PIO A26A2 AM OFFSET AND PULSE SWITCHING ASSY 08640 500141 SCHMITT TRIGGER ec i t NS 13 Eu Ca eu po R22 51 1 15 1 SEE NOTE 1 T 1 TN I GND PUL IN o 0 lt 2 used
19. Source EXT 0 550 RANGE 0 5 1 MHz FREQUENCY TUNE Full RFON OFF ON NOTE If in LOCK mode the frequency at RF QUT differs by one count in the least significant digit from the frequency indicated on the display 1 ambiguity of the counter the problem is probably caused by the total gate delays in the lock circuit Replace 842014 If the counter won t phase lock on a certain count ina certain digit but will lock on all other counts displayed by that digit replace that digit s up down counter Counter Time Base A8A3 A9 SERVICE SHEET 19 Service SERVICE SHEET 20 Cont d Component or Circuit Up Down Counter and Display Troubleshooting Test Conditians and Control Settings SHAPING A8A2 INPUT GATING A8A2 COUNTERS STORAGE BUFFERS A8A2 AND DISPLAY A8 Initial conditions and settings Set COUNTER MODE to EXT 0 10 MHz Normal Indication Model 6640B Option 094 If Indication is Abnormal Pulse width at U13A pin 3 2225 ns high going pulse Check U2 U18 U14 U15 and associated circuitry Initial conditions and settings Set COUNTER MODE to EXT Q 10 MHz Initial conditions and settings Ground TP2 to disable Storage Buffers Vary test oseillator frequeney Ground TP4 shown on Service Sheet 21 to disable Flash Oscillator and phase lock error signal Then set COUN
20. 8444A HP 5327C 11592 60001 1250 0827 HP HP 1 Connect equipment as shown in Figure 5 9 after setting Signal Generator s controls as follows RANGE FREQUENCY TUNE RF ON OFF 256 512 MHz Fully cw OFF 2 Set spectrum analyzer center frequency to 550 MHz frequency span scan width to 100 MHz per division resolution bandwidth to 10 kHz and input attenuation to 20 dB 3 Set tracking generator s output level to O dBm Adjust the tracking for maximum response in a 10 kHz resolution bandwidth Tracking should be checked periodically during this test Set analyzer s resolution bandwidth to 300 kHz 4 For each of the frequency range bands listed in Table 5 3 perform the following a Connect spectrum analyzer s RF input to tracking generator s RF output use test cables and adapter as shown in test setup Set Signal Generators RANGE and FREQUENCY TUNE controls as listed in the table Set spectrum analyzer s frequency span scan width controls to zero Hz 5 30 Model 8640B Option 004 Adjustments ADJUSTMENTS 5 39 RF FILTER ADJUSTMENT Cont d NOTE Geometric mean switching on the 8 to 512 MHz bands occurs near the middle of the frequency range Switching is controlled by the position of the FREQUENCY TUNE control and switches between the high and low band filters for the frequency range It can be noted either by listening for the faint but audible clicking of the RF relays or by observing a cha
21. AM OUT associated circuitry 8 46 Model 8640B Option 004 Service 13 MODULATION METER ING P O A26 AM AGC AND RF AMPLIFIER ASSY 08640 60058 LL LLL LL REFERENCE DESIGNATIONS MOTHER BOARD ASSY 08640 60057 A26A2 AM OFFSET AND PULSE SWITCHING ASSY 08640 60014 1 NO PREFIX 50 RD ASSY ie NOPREFIX P O A26A6 I og P O A26A5 RISER AM MOTHER BOARD mms AM OFFSET AMPLIFIER B ASSY 08640 60068 ASSY 08640 60067 20V 20V 20V 20V P O P1 P3 R2 R2 R7 R9 R14 7500 7500 825 825 5 12 13 k XA26A6 AM b s INPUTIQUTPUT CR CF UD fy Fp b c913 RETURN ag lt 2 P O 52 P O XA26A6 A26A6 P O 17 P O XA26A2 P O XA26A5 DELETED A26A2C9 ee A26A6_ i AMIN i PIO Pn TO MOD OSC XA26A2 1 XA26A2 PIN 12 1 lt 1 i 1 1 i 1 1 gt 16 RF VERNIER MOTHER TO MOD SUPPLY MOTHER METER MOTHER BOARD ASSY 08640 60018 08640 60001 0 5 RISER ASSY PS POWER 1 1 1 1 1 1 1 1 1 rt 1 1 i I 94V e 2 2 e 9 i 0 eee 15 Figure 8 50 P O 26 2 AM Offset and Pulse Switching Assembly Component Locations 9 R6 R12 R15 TO
22. Flatness 0 5 dB Compatible with Spectrum Analyzer 1 18 Model 8640B Option 004 General Information Table 1 2 Recommended Test Equipment 6 of 6 Instrument Type x Critical Specifications Suggested Model VSWR Bridge Range 0 45 550 MHz Wiltron Model Directivity gt 40 dB 60N50 Connectors Type N P Performance A Adjustments T Troubleshooting Table 1 3 Recommended Test Accessories Nine Inch Cable BNC Male connectors coaxial HP 10502A GEM SPST Switch HP 3101 0163 1 19 General Information Model 8640B Option 004 HP 08640 60502 520 1040 MHz NOTCH FILTER 2 8 pF CERAMIC TRIMMER HP 0121 0060 BNC MALE CONNECTOR 1250 0045 BNC FEMALE CONNECTOR HP 1250 0083 1 5 INCH NO 18 ENAMELED WIRE 2 TURNS BOX AND LID REJECTION 60 dB AT NOTCH NOTCH FREQUENCY ACCURACY 500 540 MHz Figure 1 7 520 1040 MHz Notch Filter HP 08640 60503 FM LINEARITY CIRCUIT RA REF o RI LEVEL e VARO 1 1 511 OUTPUT OUTPUT VOLTAGE DIVIDER x R4 1780 1 4 WATT 0698 3439 1000 1 4 WATT HP 0757 0401 R2 2500 VARIABLE HP 2100 2726 S1 2 SPST SWITCH HP 3101 1655 R3 20kQ 1 4 WATT 0757 0449 J1 3 BNC FEMALE CONNECTOR 1250 0083 BOX AND LID Figure 1 8 FM Linearity Circuit 1 20 Model 8640B Option 004 General Information HP 08640 60504 NOISE PHASE LOCK CIRCUIT MIXER
23. DISTORTION ANALYZER 6000 FEEDTHROUGH Figure 4 17 Internal Modulation Oscillator Distortion Test Setup EQUIPMENT Distortion Analyzer HP 333A 600 Ohm Feedthrough Hp 11095A PROCEDURE Connect equipment as shown in Figure 4 17 after setting Signal Generator s controls as follows AM e s s s s NT AUDIO OUTPUT LEVEL MODULATION FREQUENCY AS specified 2 Set the MODULATION FREQUENCY controls to various frequencies within the variable ranges shorn below At each frequency tested calibrate the distortion analyzer and measure the distortion It should be as shown 4 55 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 33 INTERNAL MODULATION OSCILLATOR DISTORTION TEST Option 001 Cont d 20 Hz to 2 kHz lt 0 5 2 kHz to 600 kHz 3 Set MODULATION FREQUENCY controls to the 400 Hz and 1 kHz fixed frequencies Distortion at both frequencies should be below 0 25 400 Hz 0 2596 1 kHz 0 25 4 34 AM 3 dB BANDWIDTH TEST SPECIFICATION AM 3 dB Bandwidth Frequency Bands to 50 50 to 90 AM 0 5 2 MHz 2 8 MHz 8 512 MHz DESCRIPTION An audio spectrum analyzer is used to measure the 3 dB rate The analyzer is set to sweep over the specified audio frequency range and its tracking generator output is used to amplitude modulate the Signal Generator The generato
24. Initial conditions and Check DS4 settings except set ciator lit Meter Function to FM Set PEAK DEVIA 0 10 SCALE annun Check DS6 TION to 10 kHz ciator lit Set PEAK DEVIA TION to 20 kHz 0 3 SCALE annun ciator lit EX CLUSIVE OR INVERT and LAMP DRIVE LOGIC 403 U4 Initial conditions and settings Set MODU LATION fully cew Check 055 0 3 SCALE annun ciator lit Set MODULATION fully cw 0 10 SCALE annun clator lit Set Meter Function to LEVEL 0 3 SCALE annun clator lit Set OUTPUT LEVEL 10 dB switch to t0dBm 0 10SCALE annun ciator hit A2 TP3 Check U3 U4 and Q3 Check U3 U4 Q2 and Q3 Figure 8 56 A2 Meter Switch Detector Assembly Component Locations 8 52 Model 8640B Option 004 Figure 8 57 A4 Meter Annunciator Drive Assembly Component Locations Figure 8 58 P O A6 Annunciator Assembly Component Locations Service AB er a eg UM MM A2 METER SWITCH GETECTOR ASSEMBLY 0864376055 PO __ _ _ ____ MOHER BD Ad METER ANNUNCIATOR DRIVE ASSEMBLY 08640 60056 MOTHER BD REFERENCE DESIGNATIONS MOTHER BD ASSY 08640 60057 M gamm BUFFER AMPL mm mmm POSITIVE PEAK DETECTOR muamma eio 20V 15 GAIN 21 cl 0 01 10V umm NETER DRIVE AMPL SS R21 C5 10M DELETED A2R1 A4R8 P O NOTE
25. NOTE When re installing RF Oscillator Assembly loosen collar 2 on fine tune shaft After installation press collar and RFI gasket 1 firmly against front panel and secure collar setscrew 3 A3A1A2 Removal Procedure 1 Remove eight 4 40 screws 47 securing cover plate to buffer housing 2 Unsolder three leads connecting buffer board and two feedthrough filters 53 and 54 and RF connector 40 3 Remove two 6 32 50 securing the buffer board to the housing SERVICE SHEET B Cent d 4 Lift out buffer board ensuring that attached probe does not bind in cavity opening NOTE The buffer board has two adjustment slots for attaching to the housing Refer to the adjustment procedure in when reinstalling the buffer board A3A1A3 Removal Procedure 1 Remove eight 4 40 screws 21 securing cover plate to buffer housing 2 Unsolder three leads connecting buffer board and two feedthrough filters 35 and 36 and RF connector 37 3 Remove two 6 32 24 securing the buffer board to the housing 4 Lift out buffer board ensuring that attached probe does not bind in cavity opening NOTE The buffer board has two adjustment slots for attaching to the housing Refer to the adjustment procedure in when reinstalling the buffer board Replacement Procedure 1 Unscrew transistor cap 32 2 Remove transistor 55 3 new transistor leads as shown Figure 8 82 4 Re insert transistor as
26. Scale lamps determined by PEAK DEVIATION switch L 0 to 0 8 Vde H 3to 5 2 Vde SERVICE SHEET 17 TROUBLESHOOTING it is assumed that a problem has been isolated to the meter circuits as a result of using the troubleshooting block diagrams Trouble shoot by using the test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital Voltmeter 2 42 445 664 ee HP 3480D 3484A Oscilloscope HP 180A 1801A 1820C Initial Test Conditions Top cover trim strip and front panel window removed see Service Sheet G for removal procedure Use extender board to SERVICE SHEET 17 Cont d extend desired circuit board assembly set instrument LINE power switch to OFF while removing or inserling circuit boards Initial Control Settings Meter Function AM A MODULATION FREQUENCY 1 kHz soaba d mou c RE wb ew aaga a ANT PEAK DEVIATION 5 kHz OUTPUT LEVEL Switches Lou d 0 dBm 0 0 OUTPUT LEVEL Vernier CAL REF ON OFF Meter Circuits Troubleshooting 1 of 2 Test Conditions and nent or Circui i Component or Circuit Control Settings BUFFER 211 Initial conditions and settings Adjust MODULATION for a 2 Vp p 1 Vpk signal at TP3 AC IN Normal Indic
27. Set FM to OFF and use DVM to check dc voltages shown on schematic 2Vp p at TP5 BUFFER IN arethe same Switch RANGE through all ranges and check gain Gain in accordance Check switching of with FM system A9 gain table on sche matic RF Oscillator A3 4 SERVICE SHEET 5 Service 8 28 8840 60 GEOR iLO Figure 8 24 Model 8640B Option 004 A13 Component Locations for Al 3 Assem bly are on Service Sheet 25 P O A3A4 Connector Board Assembly Component Locations Figure 8 25 A9 TOP VIEW P O A9 Peak Deviation and Range Switch Assembly Component Locations 1 of 2 Model 8640B Option 004 A9 BOTTOM VIEW Figure 8 25 P O A9 Peak Deviation and Range Switch Assembly Component Locations 2 of 2 Figure 8 26 A5 FM Amplifier Assembly Component Locations P O 413 MODULATION METERING A9 PEAK DEVIATION AND MOTHER BOARD ASSY 08640 60057 RANGE SWITCH ASSY 08640 60117 Al 5 FM AMPLIFIER ASSY 08640 60029 DL __ DEVIATION VERNIER jm BUFFER AMPLIFIER GAIN 1 m BUFFER OUT Li 20V 1 P M PEAK SUFFER f DEVIATION ji lt 2 4NN F l t 8 T FM ENABLE 11 FROM E 5 5 24 i MODULATION t OSCILLATOR MODULATION ae 1 SCILLATOR P ommum Ed AMPLIFIER 9 44 VIF 44 OVE 44 VIF R25 00 tici 2 2 pF
28. 22 A9A1MP23 A9A1MP24 A9A1MP25 A9A1MP26 A9A1MP27 A9A1MP28 A9A1MP29 A9A1MP30 A9A1MP31 A9A1MP32 A9A1MP33 A9A1MP34 A9A1MP35 A9A1MP36 A9A1MP37 A9A1MP38 A9AIMP39 A9A1MP40 A9A1MP41 9 1 1 A9ATWI 9 1 1 9 1 1 1 9 1 1 2 AO ATAIR3 A9ATAIRA A9ATATRS5 AO AIAIR6 9 1 1 7 A9ATATRS8 A9ATATR9 A9ATAISI A9ATAIS2 7 38 1460 0019 1460 0019 2190 0390 3050 0103 3050 0103 3050 0103 3130 0503 3130 0504 08640 00091 08640 00092 08640 00093 08640 00098 08640 20241 08640 20242 08640 20248 08640 20249 08640 20250 2360 0220 2360 0123 2260 0009 0520 0173 2360 0135 2200 0107 2360 0129 2190 0006 2950 0006 2190 0027 2100 3435 08640 60197 08640 60253 0698 8299 0698 8298 0698 8297 0757 0398 0698 8296 0757 0399 0698 8295 0757 0400 0757 0400 08640 90073 SPRING COMPRESSION SPRING COMPRESSION WASHER FLAT NON METALIC WASHER FLAT WASHER FLAT WASHER FLAT SHAFT INDEXASSY SHAFT INDEXASSY MOUNTING PLATE DETENTS MOUNTING PLATE GEARS MOUNTING PLATE POT BOARD SUPPORT BUSHING PLASTIC SHAFT FMGAIN SWITCH SWITCH ROTOR 4CONTACT P O A9A1A2SI SWITCH ROTOR 3 CONTACT P OA9AIAIS2 SWITCH ROTOR 2 A9A1AISI SCREW 6 32X2 25 SCREW 6 32X6 25 W LOCK NUT 4 40w LocK SCREW 2 56X0 25 W LOCK SCREW 6 32X1 50 SCREW 4 40X0 312 W LOCK SCREW 6 32X1 000 LG WASHER SPLIT LOCK NUT 1 4 32 WASHER LOCK INT STAR RESISTOR
29. 5910 00 728 4974 5962 01 007 2815 5910 00 879 6053 5930 00 412 0939 5962 00 563 1929 5962 00 405 3777 5962 00 935 0162 5962 00 466 1654 5962 00 450 8830 5962 00 117 8726 5962 00 443 9486 5962 00 865 4625 5962 00 103 0990 5962 00 404 2559 5962 00 229 8500 5962 00 474 3469 5962 00 156 0983 5962 00 172 5563 5962 00 276 9929 5962 00 106 4287 5962 00 102 7519 5962 00 404 6174 5962 00 497 1587 5961 00 496 7363 5961 00 873 0867 NUMBER 5211213 278 517843 0121 0036 0121 0060 0121 0061 0140 0177 0140 0190 0140 0195 0140 0198 0140 0199 0140 0200 0140 0205 0140 0219 0140 0220 0140 0226 0140 0233 0140 0234 0160 0128 0160 0157 0160 0158 0160 0161 0160 0168 0160 0174 0160 0297 0160 0300 0160 0335 0160 0341 0160 0342 0160 0839 0160 0939 0160 2049 5 4713 7263 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 NATIONAL STOCK NUMBER 5961 00 787 4343 5961 00 917 0660 5910 00 463 5960 5910 00 767 4977 5910 00 983 2623 5910 00 917 9737 5910 00 852 3004 5910 00 776 8913 5910 00 914 2605 5910 00 914 2604 5910 00 914 4732 5910 00 782 1853
30. 8 51 The set S and clear CLR inputs override all other input conditions when S is low Q is forced high when CLR is low Q is forced low Although normally the Q output is the compliment of the Q output simultaneous low inputs at S and CLR will force both Q and Q high on some J K flip flops JIK FLIP FLOP Q NO CHANGE 0 1 TOGGLES Figure 8 8 J K Flip Flop 8 52 Multiple Input J K Flip Flop A multiple input J K flip flop is shown in It behaves like a J K flip flop with NORed inputs if A B and C are low J is high if A B or C is high J is low A J related and a K related input may be tied together to form a trigger input in this case the trigger would be active low if all other inputs are low 8 53 Binary Registers 8 54 Binary Latch The four bit binary register shown ib Figure 810 is used as a storage latch In formation data Dn inputs is transferred to the respective Q outputs when the enable EN input 8 8 Model 8640B Option 004 is low When the enable goes high the outputs are latched and are no longer affected by the data inputs MULTIPLE INPUT J K FLIP FLOP TOGGLES NO CHANGE YandZ 0 Figure 8 9 Multiple Input J K Flip Flop 8 55 When enabled any output may be set to a high by a low on the respective set Sn input which overrides the data input When not enabled the set inputs have no effect on the outputs 8 56 A low on the master clear CLR
31. A4R6 A4R7 A4R8 AA4R9 A4R10 4 11 A4R12 A4R13 A4R14 A4R15 A4R16 A4R17 A4R18 A4R19 A4R20 A4R21 A4R22 AATPI BATP2 AATP3 AATPA BATPS 4 6 AATPT 401 A4U2 A4U3 404 AAVRI BAVR2 AS 5 1 A5C2 A5C3 ASC4 5 5 5 6 A5C7 A5C8 5 9 ASCR1 ASCR2 5 ASCR4 A5CR5 HP PART NUMBER 0698 3439 0757 0416 0757 0416 0360 1514 0360 1514 08640 60056 0160 2199 0180 0228 0160 2055 0160 2055 0160 2199 1901 0040 1901 0025 4040 0750 1480 0073 1854 0071 1854 0019 1854 0019 0757 0442 0757 0442 0757 0199 0698 3444 0757 0460 0757 0280 0757 0442 0698 3193 2100 2514 0698 3193 0757 0279 0757 0280 0757 0280 0757 0346 0757 0346 0698 7340 0698 8307 2100 2521 0757 0288 0683 1065 0698 5094 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 1820 0223 1820 0223 1820 0054 1820 0511 1902 0025 1902 0025 08640 60029 0160 2228 0160 2228 0180 0116 0180 1715 0180 0269 0180 0197 0180 0116 0180 2211 0160 0939 1901 0025 QTY 1 21 21 18 Mo RR T TABLE 6 3 REPLACEABLE PARTS DESCRIPTION NOT ASSIGNED RESISTOR 178 OHM 1 RESISTOR 511 OHM 1 RESISTOR 511 OHM 1 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR TERMINAL SLDR STUD TERMINAL SLDR STUD NOT ASSIGNED BOARD ASSY METER DRIVER CAPACITOR FXD 30PF 5 300WVDC MICA CAPACITOR FXD 220 10 15VDC TA SOLID C
32. A9A2 ates tov ant NIN ios Figure 8 25B A9A2 Interconnect Assembly Component Locations P O Change 7 Etel P O A13 MODULATION METERING MOTHER BOARD ASSY 08640 60057 FROM MODULATION OSCILLATOR FROM MODULATION 1 OSCILLATOR FM ENABLE L P O Figure 8 27 A9 PEAK DEVIATION AND RANGE SWITCH ASSEMBLY P O A9A2 INTERCONNECT ASSEMBLY 08640 60256 PIO PIO P O Pl Wi Jl P2 2 Amplifiers Schematic Diagram 1 of 2 P O Change 7 9 1 SWITCH ASSY mum Q oeviarion ATION VERNIER P O A9A2 INTERCONNECT ASSY p 9 2 1 pauo3 39 9 00 uondo 30798 81006 07980 P O A9 PEAK DEVIATION AND RANGE SWITCH ASSEMBLY PEAK DEVIATION AND RANGE SWITCH 5 000000000 SWITCH ASSEMBLY 0860 6009 O O O OO O O OOO d 10 FM GAIN SWITCH BOARD ASSEMBLY 08640 60254 m m t FM SYSTEM GAIN dB FROM ASTP3 TO ASTPA WITH A7 REMOVED OR WITH LEVELS AT ASTPA lt 0 3 ms TO OVER XAS DEVIATION E 8 16 32 8 108 256 51 TO 8 256 512 1024 L 1 Q DIFFERENTIAL GEARING 1 DEVIATION 1 i 1 ALL VOLTAGES ARE WITH FM SWITCH SET TO OFF TOLERANCE 1 10 2 NORMALLY OPEN t SEE BACKDATING TABLES 7 1 AND 7 2 REFERENCE DESIGNATIONS o o o PIO A9A2 INTERCONNECT
33. Adjust spectrum analyzer s vertical sensitivity to give digital voltmeter reading of 282 8 mV Voff e g if Voff from step 8c is 50 0 mV adjust the spectrum analyzer to give a digital voltmeter reading of 232 8 mVdc 4 67 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 38 DEMODULATED OUTPUT ACCURACY TEST Cont d If AC DC switch A26A8S1 is set to AC 13 Set the digital voltmeter to read mVrms and adjust the test oscillator level to give the readings listed below For each setting switch the digital voltmeter to read the ac DEMOD OUTPUT voltage which should read within the specified limits NOTE AM distortion must be lt 1 for this test to be valid DEMOD OUTPUT Voltage mVrms Digital 20 30 c Voltmeter Using mVrms DEMOD CAL Label 970 1030 980 1020 1 1455 1545 1470 1530 of 1940 2060 1960 2040 value 2425 2575 2450 2550 on 2910 3090 2940 3060 DEMOD CAL 3395 3605 3430 3570 Label X 5 3880 4120 3920 4080 If AC DC switch A26A8S1 is set to DC 14 Repeat step 13 The DEMOD OUTPUT voltage should be within the limits specified in the following table DEMOD OUTPUT Voltage mVrms Digital 20 30 c Voltmeter Using mVrms DEMOD CAL Label 1 of value on DEMOD CAL Label 4 68 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 38 DEMODULATED OUTPUT ACCURACY TEST Cont d 15 Set the Signal Generator RANGE to 256 512 MHz FREQUENCY TUNE TO
34. DET PUL MOD PUL DBLR LVL METER ADJ MET DET OVLD VERN GND CQ1 DRVR MOD GAIN AC OFFSET AC GAIN DC GAIN DC OFFSET AC DC BUFFER DET 6 DEMOD DEMODULATION AMPLIFIER ASSY A26A4 AGC AMPLIFIER ASSY A26A2 AM OFFSET AND PULSE SWITCHING ASSY 35 39 1 A10A1 RF FILTER 09 ASSY 4 15 CU 48 4 90 49 Ji ABA COUNTER LOCK BOARD ASSY 12 A6 A10A2 ANNUNCIATOR RF DIVIDER ASSY ASSY aervice SPARE 16 18051 ATBPI A24SERIES 2672 PARTS 44 6 MOTOR 5 2 REGULATOR ASSY SOCKET OUTPUT JB ASSY TIME BASE 83 EXT INT 2045 2 AND 44 6 REGULATOR ASSY POWER ASSY A22052 20V 641 5 2V Ch 5 2V A20082 5 2V C1 20V A26 AM AGC AND RF C2 20V AMPLIFIER ASSY A12 A22 420V AND 20V RECTIFIER REGULATOR ASSY ASSY A22DS1 20V TI 20051 44 6 EXTENDER 18 5 2 REGULATOR BOARD AND FAN DRIVER ASSY A2 METER SWITCH A10 DIVIDER FILTER ASSY DETECTOR ASSY A4 ANNUNCIATOR DRIVE ASSY A13 MODULATION METERING MOTHER BOARD ASSY COUNTER LOCK M1 ASSY Figure 8 90 Top Internal Views Option 001 Shown B 83 8 84 Model 8640B Option 004 SERVICE SHEET H SERVICE SHEET Cont d OUTPUT LEVEL VERNIER VARACT
35. FM ENABLE tE 4 00 830 9 110K 555 AMPLIFIER 44 OVIF 44 6V0F 44 SVIF 44 PI maur R R5 RID 3 INPUT 1330 1330 pog AMPLIFIER OFFSET 2610 x FM AMPLIFIERS DFTION QU 1408A pig 0 A3 RF OSCILLATOR AS SY 08640 60099 PUAS ammmamumm FM GAIN COMPENSATION mmmn um LOWSENS AD FREQUENCY TO OVER DEVIATION DETECTOR PEAK ox DEVEATION Q DIFFERENTIAL GEARING Service E FM SYSTEM GAIN dB FROM ASTP3 TO ASTPA WITH REMOVED OR WITH LEVELS AT ASTPA lt 0 3Vr ms REA I Ex 5 12 MHz a son arr CLUDES ASSEMBLY NUMBER p RI OF ASSEMBLY 15 DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE 5 SHOWN i 1 i 1 RANGE GAIN m Set ee a a ee ae E cep eee SES A eae 1 E 3 S3CF t 4 11 LH nd r 1 1 I i x 41 ge LI 1 i 2H j 4 11 i a 18 e Aly 3 DM J d F it 4 tl RIG 1 f 2000 7 ai gn t ZR 7 41 21 11 23 i PIO 4 n 5 i 7 710 S NO PREFIX i GAIN p 5 R 5 j 4 R QAdB 7 1 2 12 WL D
36. FM OUTPUT 6001 TERMINATION 1 02 0 5 Vim AT 400 Hr ALS MODULATION ARE TERING MOTHER BO ASSY Wa x 4 E NE RENE Plus T 0 09 3 l redeo olga 1 pig 2d vow p i t a Quien AMORFM cl INT MODULATION FREQUENCY B40 20 mvrm AT 400 Hz MODULATION FREQUENCY 1 5 0 5 400 B Hz 1000 1 mVdc AB PEAK DEVIATION AND RANGE SWITCH ASSY mu t DEVIATION i t is i CAL BUFFER AMPLIFISR MODULATION FREQUENCY 840 20 mVrms MODULATION OSCILLATOR ATT FIXED FREQUENCY MODULATION OSCILLATOR od MODULATION FREQUENCY 400 Hz FM b de RANGE FREQUENCY TUNE INT B 1 MHz CENTERED PEAK DEVIATION VERNIER SET FOR AT 2 Vpp 1 3 AT ASTPS 20 Vp p ABTP2 93 INT AUDIO DUTPUT 93 AT 400 Hz PIO AMPLIA Service sr n nr n n n MODULATION FREOUENCY WO Hr METER FUNCTION FM PEAK DEVIATION VERNIER METER DE READS 6 0 FM INPUT NOCOMNECTION 2mh FM SHAPING CIRCUITS AND PHASE LOCK LOOP FILTER RF OSCILLATOR FO AB PEAK DEVIATION i AND RANGE SWITCH ASSY P O
37. FM SHAPING ASSY AF OSCILLATOR ASEY 1 A cm a a V P Al 3 LEVEL 12 2 dam 32 TO 2 dom i FREQUENCY 229 5 0 4 MHz 5505 0 5 I po 4 I TUNE COUNTER i SUFFER E j ENTIAL FINE i i GEARING VARACTOR CATHODE 11 25 52 E VARACTOR EE el i p VABACTOR ANOOE i i 3 256 512 MHz 1 F FREQUENCY TUNE CW LEVEE 05 4 5 dim 6 5 TO 4 5 dBm FREQUENCY 229 612 MHz 550 5 0 5 POSITIVE SHAPING FM ENABLE VARACTOR o ANODE sa PHASE dm 4 147 0 5 Woe v Hi d g POWER SUPPLIES 2V AND 44 5V REGULATOR ASSY Azo rd REGULATOR A23 IV AND 20V REGULATOR ASSY evo REGULATOR i DH REGULATOR SET CONTROLS AS FOLLOWS OVER DEVIATION DETECTOR AND METER CONTROL CIRCUITS UNLESS OTHERWISE SPECIFIED METER FUNCTION COUNTER MODE EXPAND LOCK TIME BASE VERMIER M LOCK A 5 7v POWER SUPPLY AND FAN 52Y REGULATOR AND FAN DRIVER ASSY A18 a EGULATOR P O AG ANNUACLATOR ASGY M DEVIATION REDUCE FM VERNIER FAQ FM SHAPING ASSY 5 Mg DETECTOR FAN DRIVER PEAK DEVIATION SWITCH PEAK DEV
38. Initial conditions and settings Set FREQUENCY TUNE to 256 MHz RF Filter Troubleshooting RF FILTERS A10A1 ye T Initial conditions and settings then set RANGE to each posi tion and tune FRE QUENCY TUNE full CW and full CCW x i A10A1 BOTTOM VIEW ea p IE 3 o DC continuity across con tacts of K2 and K4 DC continuity across con Check Kl K3 and tacts of K1 and K3 associated circuitry O dBm on panel meter Model 8640B Option 004 Normal Indication If Indication is Abnormal Check K2 K4 and associated circuitry Check appropriate switch contacts and appropriate high and low band filters Figure 8 39 RF Filter Assembly Component Locations 1 of 2 aervice Model 8640B Option 004 P O AIO DI VIDER FILTER ASSY 08540 60105 VP a UL tame 5 wa BIGHI OW BANI RELAYS Trara 1 120 FROM MODULATO FILT IN FILT QUT 13 aver isi Wi ar DOU cT Tn eee ens EC 4 RF TO MODULATOR NE a T ERIT E A Col 3 2156 a 89 128 256 2 BAND o 525 84 4 8 MHz BAND NOT USED EE 512 3024 MHz 30 NEUTRAL
39. Power Meter Power Sensor NOTE The sensor s VSWR should be 1 2 1 max PROCEDURE Model 8640B Option 004 HP 435A 8482A 1 Connect equipment as shown in Figure 4 12 after setting Signal Generator s controls as follows Meter Function E LEVEL COUNTER MODE EXPAND Off LOCK Off Source OFF FM OFF RANG E 128 256 MHz FREQUENCY TUNE 190 MHz OUTPUT LEVEL 10 dB 10 dBm OUTPUT LEVEL 14 OdB OUTPUT LEVEL Vernier CAL RF ON OFF 2 Adjust OUTPUT LEVEL Vernier for a power meter reading of 9 dBm at 190 MHz Using RANGE and FREQUENCY TUNE controls slowly tune Signal Generator from 0 5 to 512 MHz Within the ranges listed below note maximum and minimum power readings in dBm 3 In the 108 to 336 MHz range the maximum and minimum readings should be within 0 5 dB of the reading at 190 MHz maximum reading _ 0 5 dB minimum reading 0 5 dB 4 The overall maximum and overall minimum readings 0 5 to 512 MHz should be within 0 75 dB of the reading at 190 MHz maximum reading 0 75 dB minimum reading 0 75 dB 4 46 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 428 OUTPUT IMPEDANCE TEST Signal Frequency SPECIFICATION Impedance 502 ac coupled 40 Vdc maximum VSWR 2 0 on and 1V output ranges 1 3 on all other ranges DESCRIPTION The generator s output signal is reflected back into the RF OUT jack by a coaxial short at the end of an adjustable stub a vari
40. Set variable voltage transformer 10 below nominal line voltage e g for a nominal 120 Vat set transformer for 108 Vat then note the reference frequency The frequency change from the reading noted in step 7 should be 0 52 Hz 0 1 ppm 1 digit counter ambiguity Voltage 0 52 Hz NOTE Any change in chamber temperature could make the instrument s drift rate us voltage appear out of specification Reset transformer to nominal line voltage Set temperature controlled chamber to 15 C Wait two hours to allow generator s internal reference to stabilize then note its frequency Set temperature controlled chamber to 35 C Wait two hours then note the reference frequency The frequency change from the reading noted in step 9 should be 10 2 Hz 1 lt 2 ppm 1 digit counter ambiguity Temperature 10 2 Hz Note generator s internal reference frequency connect coaxial short to RF OUT then again note reference frequency Except for the 1 digit count ambiguity it should not have changed Load No Change 4 91 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 49 INTERNAL REFERENCE DRIFT RATE STABILITY TEST Cent d 12 Remove coaxial short Note internal reference frequency set OUTPUT LEVEL 10 dB switch one step ccw to 10 dBm then again note reference frequency Except for the 1 digit count ambiguity it should not have changed Level Change V No Change 13 Note internal refer
41. USE WITH LOW NOISE POWER POWER SUPPLY e g BATTERIES 30 pF HP 0160 2199 7 5 2 AND 7 5 2 350 uF 15V HP 0180 2216 0 27 uF 0160 2406 DIODE HP 1901 0033 BOX AND LID BNC FEMALE CONN HP 1250 0083 5110 HP 0757 0416 31 6 HP 0698 3160 10 0 HP 0757 0442 6190 HP 0757 0418 31 60 0698 3155 1820 0223 Figure 1 9 Noise Phase Lock Circuit 1 21 1 22 Model 8640B Option 004 Installation SECTION 11 INSTALLATION 2 1 INTRODUCTION 2 2 This section explains how to prepare the Model 8640B Option 004 Signal Generator for use It explains how to connect the instrument to accept available line voltage and it also describes bench operation rack mounting storage and shipment 2 3 INITIAL INSPECTION 2 4 Inspect the shipping container for damage If the shipping container or cushioning material is damaded it should be kept until the contents of the shipment have been checked for completeness and the instrument has been checked mechanically and electrically The contents of the shipment should be as shown in Figure 1 1 and procedures for checking electrical performance are given in If the contents are incomplete if there is mechanical damage or defect or if the instru ment does not pass the electrical performance test refer tol paragraph 0 4 If the shipping container is damaged or the cushioning material shows signs of stress
42. n ji uw 1553 aw lt m 0Y 0007 2 Figure 8 44 A26A8 Modulator Assembly Component Locations 0 5 2 i t fr Ql 1954 if Ma 021 4 SRO C6 RO 1 Tl ll R57 Go mv Ze NS Qr ME c e T pe 0 BOK REFERENCE DESIGNATIONS m emm PULSE OVERLOAD DETECTOR man AN A R3 us 3830 Powew C cae 13 7 5000 6190 13 ony Ovid CRIs OFF Lb WV 6 n i 3 Er Vemm MODULATOR DRIVER AMPLIFIER umm 9 1 2 wn i OVERLOAD 15 01 9 2000 6190 1500 crs ou A771 n2 RLM A30 R52 57 RB cue i 1 Cl 51 KI i TP1 8 i 4 A aiv R35 amm NETER AMPLIFIER ammm MET 11 2 VRL ti 5L ik 45 2 2j 1 4 1 t a LA p 1826 002 352 2 018 CIRCUIT BOARD TOP VIEW Hae n Fog METER V lcs a REDUCE PK 8 DELETED 26 4 5 A26A4R37 AZ6A4R5 e wt w 015 000000 i CRIS 0 1 NOTES BO MODULATOR OVERLOAD DETECTOR mme 1 OPEN COLLECTOR o 5 2 Y 2 NON FUNCTIONING LINE 2 T RM Histor QUK ch e LO pF L MN a n a a 2222
43. nn E _ A26 A26A3 A2Z6A4 AMPLIFIER ABD AMPLITUCE MODULATOR OPTION 004 13714 Figure 8 46 AGC Amplifiers and Amplitude Modulator Schematic Diagram Figure 8 45 A26A4 AGC Amplifier Assembly Component Locations 8 43 SERVICE SHEET 13 PRINCIPLES OF OPERATION General The RF signal from the RF Filters is amplified by RF Output Amplifier A26U1 The amplifier is a sealed microcircuit that plugs into the rear of the AGC detector board The amplifier drives resistor UIR1 which sets the amplifier output impedance The output is ac coupled through U1C2 and drives the two Output Attenuators The step attenuators consist of resistive attenuator sections which are switched in and out by cam driven micro switches The attenuators consist of a 6 dB step 10 dB steps and 1 dB steps with an impedance of 50 2 Capacitor A19A1CI ac couples the RF output to the RF OUT jack AGC Detector A26U1 The AGC detector CR1 detects the negative peaks of the RF signal from the Output Amplifier The detector output is summed with the positive AGC reference voltage in the Summing Amplifier Service Sheet 12 Detector diode conducts when ever the RF amplifier output is one diode junction voltage drop below the voltage across C3 The capacitor is then negatively charged until the amplifier voltage rises at which time shuts off C3 then slowly discharges through resistor A26A1R23 until another negative peak recharges it FET
44. 0698 3154 0757 0401 0757 0438 2100 3123 0698 0084 0683 0275 0698 3439 0757 0397 0698 3447 0811 1668 0698 7260 0698 7260 0757 0278 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 TABLE 6 3 DESCRIPTION REPLACEABLE PARTS DIODE ZNR 6 19V 5 DO 7 PD 4W CONNECTOR 1 SKT 04 DIA CONNECTOR 1 CONT SKT 04 DIA CONNECTOR 1 SKT 04 DIA CONNECTOR 1 CONT SKT 04 DIA NOT ASSIGNED REGULATOR ASSY 20V amp 20V CAPACITOR FXD 33UF 10 10VDC TA SOLID CAPACITOR FXD 510PF 5 100WVDC MICA CAPACITOR FXD 5600PF 10 200WVDC POLYE CAPACITOR FXD 500 75 10 25VDC AL CAPACITOR FXD 33UF 10 10VDC TA SOLID CAPACITOR FXD 510PF 5 100WVDC MICA CAPACITOR FXD 5600PF 10 200WVDC POLYE CAPACITOR FXD 50UF 75 10 25VDC AL DIODE GEN PRP 100V 200MA DIODE PWR RECT 400V 750MA DIODE SWITCHING 2NS 80V 200MA DIODE GEN PRP 100V 200MA DIODE SWITCHING 2NS 80V 200MA DIODE PWR RECT 400V 750MA PHOTO DEVICE SW PNP SI 3V 05MW PD PHOTO DEVICE SW PNP SI 3V 05MW PD FUSE 75A 125V SLO BLO FUSE 75A 125V SLO BLO EXTRACTOR P C BOARD BLACK PIN DRIVE 0 250 LG EXTRACTOR PC BOARD PIN DRIVE 0 250 LG BLUE THRYISTOR SCR JEDEC 2N3528 TRANSISTOR NPN SI TO 39 PD 1W FT 15MHZ INSULATOR XSTR TO 5 075 THK TRANSISTOR NPN SI TO 39 PD 1W FT 15MHZ INSULATOR XSTR TO 5 075 THK THYRISTOR SCR JEDEC 2N3528 RESISTOR 2 61K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 4 22K 1 125W F TUBUL
45. 10 100WVDC CER MFR CODE 24546 24546 24546 24546 24546 24546 24546 16299 24546 24546 24546 16299 16299 16299 24546 24546 24546 24546 24546 24546 04546 24546 24546 75042 24546 28480 28480 28480 28480 28480 28480 28480 01295 01295 01295 01295 01295 01295 07263 07263 07263 07263 07263 07263 01295 04713 01295 01295 0195 01295 01295 01295 01295 01295 01295 01295 01295 01295 04713 01295 04713 04713 04713 28480 28480 28480 28480 28480 28480 REPLACEABLE PARTS MFR PART NUMBER C3 1 8 TO 1002 G C3 1 8 TO 1002 G C3 1 8 TO 1472 G C3 1 8 TO 1961 G C3 1 8 TO 511R G C4 1 8 TO 1002 F C4 1 8 TO 511R F C4 1 8 TO 237R F C4 1 8 TO 1002 F C4 1 8 TO 3161 F C4 1 8 TO 1002 F C4 1 8 TO 1961 F C4 1 8 TO 1961 F C4 1 8 TO 1961 F C4 1 8 TO 511R F C4 1 8 TO 511R F C3 1 8 TO 511R G C4 1 8 TO 1001 F C3 1 8 TO 3161 G C3 1 8 TO 3161 G C3 1 8 TO 511R G C3 1 8 TO 511R G C3 1 8 TO 1001 G BWH2 47 100 J C3 1 8 TO 196R G 3101 1729 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 SN7474N SN7400N SN7400N SN7404N SN7474N SN7402N 93L14DC 93L14DC 93L14DC 93L14DC 93L14DC 93L14DC SN7408N MC3003P SN7400N SN7400N SN7408N SN7408N SN74192N SN74192N SN74192N SN74192N SN74192N SN74192N SN7402N SN7474N MC3003P SN74192N MC7812CP SZ 10939 74 SZ 10939 206 08640 60026 0160 3094 0160 3094 0160 3094 01
46. 128 TO 256 MH2 FREQUENCY MAX CCW TUNE UNCAL EXPAND OFF EXPANO X10 EXPAND X100 LEVEL 5 TO 10 dBm 5 TO 10 dBm FREQUENCY 229 6 0 4 550 5 0 5 MHz TTL SQUARE WAVE P O A8 COUNTER LOCK ASSY ABA1 RF SCALER ASSY P O A8A3 asai COUNTER MODE SOURCE EXT 0 10 COUNTER INPUT EXTERNAL 100 mV INTO 5082 AT 1 kHz RF INPUT e MODE 256 512 MHz 1 kHz TTL SQUARE WAVE AES et 3587 50 6 25 kHz TTL SQUARE WAVE EEL TO TTL TRANSLATOR EXPAND X10 TIME BASE VERNIER CAL TO MAX CCW OVERFLOW LAMP COUNTER MODE SOURCE EXT 0 10 CONNECT REAR PANEL TIME BASE OUT TO COUNTER INPUT DISPLAY 05 0 000 t1COUNT OISPLAY DOES NOT FLASH TURN FREQUENCY TUNE 1 4 TURN CW DISPLAY FLASHES AT 2 Hz RATE DECIMAL POINT FREQUENCY TUNE NORM AFTER SETTING LOCK TO ON TURN 10 FREQUENCY TUNE 1 4 TURN CCW X a EI AME Or c DISPLAY FLASHES 2 Hz RATE 100 256 512 MHz SET CONTROLS AS FOLLOWS UNLESS OTHERWISE SPECIFIED METER FUNCTION COUNTER MODE EXPAND aad NORM EXPAND DECIMAL POINT TTL VOLTAGE LEVELS 0 TO 0 4 V 24T052V FREQUENCY TUNE FINE TUNE OUTPUT LEVEL SWITCHES OUTPUT LEVEL VERNIER RF ON OFF TIME BASE REF REAR PANEL Figure 8 21 Counter Lock Circuits Block Diagram 8 25 SERVICE SHEET 5 PRINCIPLES OF OPERATION General The A3 RF Oscillator Assembly contains the ma
47. 16299 C4 1 8 TO 2872 F 24546 C4 1 8 TO 2152 F 16299 C4 1 8 TO 1782 F 24546 C4 1 8 TO 7501 F 24546 C4 1 8 TO 7501 F 24546 C4 1 8 T0 5621 F 16299 C4 1 8 TO 2871 F 24546 C4 1 8 TO 1471 F 24546 C4 1 8 TO 101 F 03888 PME55 1 8 TO 26R1 F 03888 PME55 1 8 TO 2BR7 F 16299 C4 1 8 TO 34R8 F 24546 C4 1 8 TO 42R2 F 24546 C4 1 8 TO 51R1 F REPLACEABLE PARTS REFERENCE HP PART DESIGNATION NUMBER A7R61 0757 0276 A7R62 0757 0398 A7R63 0757 0400 A7R64 0757 0403 A7R65 0757 0405 A7R66 0757 0401 A7R67 A7R68 A7R69 A7R70 0698 3150 A7R71 0757 0424 A7R72 0698 3450 A7R73 0698 3450 A7R74 0698 3150 A7R75 0757 0420 A7R76 0757 0441 A7R77 0757 0438 A7R78 0757 0346 A7R79 0757 0416 A7TP1 0360 1514 A7TP2 0360 1514 ATTP3 0360 1514 4 0360 1514 701 1826 0013 702 1820 0125 703 1820 0175 1 1902 0049 ATVR2 1902 3182 8 08640 60115 1 0160 2049 ABC2 0160 2049 ABC3 0160 2049 ABC4 0160 2049 5 0160 2357 6 0160 2357 A8FL1 0160 0204 A8FL2 0160 0204 A8FL3 0160 0204 A8FL4 0160 0204 A8L1 9100 2232 A8L2 9100 2232 A8L3 9100 2232 A8L4 9100 2232 A8L5 9100 2232 A8MP1 1200 0081 A8MP2 2190 0027 A8MP3 3050 0443 A8MP4 8160 0219 A8MP5 8160 0220 A8MP6 08640 00001 A8MP7 08640 00009 A8MP8 08640 00051 A8MP9 08640 00052 A8MP10 08640 20280 A8MP11 08640 20281 A8MP12 08640 20063 A8MP13 08640 20089 A8MP14 08640 20092 A8MP15 08640 20202 A8MP16 08640 20203 A8MP17 08640 40003 A8MP18 08640 40041 A8MP19 5040 0391 A8MP20 5
48. 7 5 Refer to paragraph 7 38 manual changes pertaining to later serial mm bered instruments Table 7 1 Manual Changes by Serial Number Make Manual Changes M L K J L H G F B A Serial Prefix or Number 1323 1327A 1332A 1333A L 3 1 H G F E D M L K J 1 H G F E M L K J I H G F M L K J I H G Make Manual Changes M L K J 1 H Serial Prefix or Number 1404A 1405A Manual Changes Model 8640B Option 004 7 2 xu of Changes mo 1 EE 2 T 4 entire sub assy A2U14 A1C17 A1C52 Model 8640B Option 004 Manual Changes Table 7 2 Summary of Changes by Component 2 of 2 R2 6 Opt 001 Manual Changes Model 8640B Option 004 MANUAL CHANGES 7 6 MANUAL CHANGE INSTRUCTIONS CHANGE A Page 6 11 Table 6 3 The recommended replacement for A844R2 is HP 2100 3216 Delete 9 8 Page 6 22 6 3 Delete A10A2C53 Page 6 23 Table 6 3 Change A10A2R55 to 0698 3151 RESISTOR FXD 2 87K 1 0 125W F TUBULAR Add A10A2R56 0757 0461 RESISTOR FXD 68 IK 1 0 125W F TUBULAR Change A10A2R58 to 0757 0458 RESISTOR FXD 51 IK 1 0 125W TUBULAR Service Sheet 6 schematic Delete A9C8 NOTE See paragraph 7 9 for recommended instrument modification Service Sheet 11 schematic Delete A10A2C53 Change A10A2R55 to 2870 Add A10A2R56 68 1K in parallel with R55 Change
49. 8 3 Illustrated Parts Breakdowns 85 8 39 Basic Circuit Theory Binary Circuits and Symbols 355 853 Binary Registers 8 8 Decade Counters and Synibals 8 9 8 68 Linear Integrated circuits 8 11 Model 8640B Option 004 Service Sheet 1 Overall Block Diagram 2 FM Circuits and RF Oscillator Troubleshooting 3 AM AGC Circuits and Output Amplifier Troubleshooting 4 Counter Lock Circuits Troubleshooting 5 RF Oscillator 6 FM Amplifiers A3 A5 9 A13 7 FM Shaping Circuits and Phase Lock Loop Filter A7 A9 8 Over Deviation Detector and Meter Control Circuits A7 A9 9 Fixed Frequency Modulation Oscillator A13 m Variable Frequency Modulation Oscillator for Option 001 All A13 10 Filters A10A1 RF Dividers A10A2 12 Amplifiers and Amplitude Modulator A26 A26A3 A26A4 13 RF Amplifier Pulse Switching and Step Attenuators A19A1 A26 26 1 26 2 14 Preamplifier A13 26 2 9 Table 1 8 2 Recommended Test Biuipsient 1 3 Recommended Test Accessories Recommended Test Abridgements Recommended Test Equipment Basic Functional Checks Record of Basic Functional Checks 4 4 Performance Test Record 5 1 Factory Selected Components Post Repair Test and Adjustments 5 3 RF Filter Check Part Numbers for Exchange Assembl
50. 8 45 Triggered Flip Flop There are two kinds of triggered flip flops The bistable triggered flip flop toggles changes states each time the trigger input T changes states shown ih Figure 8 5 This effectively divides the input by two giving one output pulse at the Q output for every two input pulses 8 46 The nonostable triggered flip flop s Q out put goes high when triggered by the T input However after a set amount of time determined either by the flip flop s configuration or unless retriggered the Q output automatically y returns to its original state The monostable flip flop or one shot is used to stretch or shape pulses TRIGGERED FLIP FLOP BISTABLE MONOSTABLE Jll iL SF Le Figure 8 5 Triggered Flip Flop 8 47 D Flip Flop The D type flip flop shown in is used as a storage latch or buffer The information at the data input D is transferred to the Q output when the trigger input T is high going Once the T input has passed its threshold the D input is locked out and the Q outputs do not change until another high going transition occurs at the T input 8 48 The set S and clear CLR inputs override all other input conditions when set is low the Q output is forced high when clear is low the Q output is forced low Although normally the Q output is the compliment of the Q output simultaneous low inputs at S and CLR will force both Q and high o
51. CHANGE 4 Page 6 34 Table 6 3 Delete A26A2CRS Service Sheet 13 schematic Delete diode A26A2CR5 Connect pin 10 directly to pin 19 CHANGE 5 Page 6 36 Table 6 3 Change A26A3R1 to 0698 7227 RESISTOR FXD 422 OHM 1 46 0 125W F Service Sheet 12 schematic Change 26 1 to 422CL 7 32 Model 8640B Option 004 08640 90073 CHANGE 6 Page 5 43 5 44 Add the attached paragraph 5 45 5 45 PHASE LOCK ERROR VOLTAGE ADJUSTMENT REFERENCE Service Sheet 21 DESCRIPTION When the instrument is operating in the normal count mode a nominal mid range phase lock error voltage should exist at test point A8SA2TP6 A mid range voltage ensures that the generator will maintain phase lock when the oscillator shifts up or down in frequency EQUIPMENT Digital Voltmeter HP 3480B 3484A PROCEDURE Set Signal Generator s controls as follows COUNTER MODE LOCK off 2 Connect one lead of the voltmeter to testpoint 8 2 and the other lead to ground Adjust potentiometer _ 8 2858 for a voltmeter reading of 11 5 1 0V dc Page 6 2 Table 6 1 Change A8A2 as follows Part Number New Assy 08640 60258 Table 6 3 Change A8A2 08640 60189 to 08640 60258 Table 6 3 Delete ASA2C27 C28 C29 and C30 Change A8A2R28 to 069 7258 RESISTOR FXD 8 25K 2 0 05W F TUBULAR Page 6 13 Table 6 3 Add A8A2R58 2100 2497 RESISTOR VAR TRMR 2K OHM 10 C TOP ADJ Service Sh
52. TO 18 TO 18 PD 360MW PD 360MW PD 1W TRANSISTOR PNP INSULATOR XSTR SI CHIP TO 39 PD 1W TO 5 075 THK RESISTOR 1 33K 1 125W F TUBULAR RESISTOR VAR TRMR 500 OHM 10 C SIDE ADJ RESISTOR 1 78K 1 125W F TUBULAR RESISTOR 4 7 OHM 5 25W CC TUBULAR RESISTOR 750 OHM 1 125W F TUBULAR RESISTOR 196 OHM 1 125W F TUBULAR RESISTOR 750 OHM 1 125W F TUBULAR RESISTOR 38 3K 1 125W F TUBULAR RESISTOR 1 OHM 5 5W PW TUBULAR RESISTOR 42 2 OHM 1 125W F TUBULAR RESISTOR 1 33K 1 125W F TUBULAR RESISTOR 68 1 OHM 1 125W F TUBULAR RESISTOR 422 OHM 1 125W F TUBULAR RESISTOR 6 19K 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR RESISTOR 68 OHM 5 2W PW TUBULAR RESISTOR 147 OHM 1 125W F TUBULAR RESISTOR 147 OHM 1 125W F TUBULAR RESISTOR 2 61K 2 05W F TUBULAR TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD IC LIN REGULATOR DIODE ZNR 2 43V 5 DO 7 PD 4W TC DIODE ZNR 5 11V 2 DO 7 PD 4W TC DIODE ZNR 6 19V 5 DO 7 PD 4W CONNECTOR 1 CONT SKT 04 DIA CONNECTOR 1 CONT SKT 04 DIA OUTPUT LEVEL ASSY 10 DB RESTORED 08640 60060 REQUIRES EXCHANGE SPACER RND 25 LG SPACER RND 188 LG SCREW MACH 5 40 PAN CCUPLER FLEX 25 ID WASHER LK HLCL NO 5 128 ID 128 ID 188 OD BRS IN 188 OD BRS 562 OD 2 45 L 128 IN ID 239 IN SCREW MACH 6 32 PAN HD POZI REC SST 300 SWITCH SGL SECT SWITCH SGL SECT ATTENUATOR ASSY NSR P O A1
53. Tl eT ool On D l 2 22 Storage and Shipment 2 23 Environment Packaging OPERATION 3 L Introduction 3 3 Panel Features 3 5 Dperators Checks 3 7 JOperating Instructions 3 9 Operator s Maintenance PERFORMANCE TESTS 4 1 Introduction 4 Equipment 5 3s 46 lest Record 4 8 est Procedures 4 12 Basic Functional Checks Table of Contents CONTENTS Page 0 1 Section BERFORMANCE TESTS cont d 4 13 Frequency Range Test 11 1 Frequency Accuracy and Fine Tune Test 4 15 Frequency Stability Vs Time and 1 2 Restabilization Time Test 1 2 4 16 Frequency Stability Vs Temperature Test 1 2 417 Frequency Stability Vs Line Voltage Test 31 18 Frequency Stability Vs Load Level and 1 3 4 Test 4 19 Harmonics Test L1 20 sub Harmonics and Non 1 4 Spurious Test 4 21 Single Sideband Phase Noise 4 22 Single Sideband Broadband Noise Floor Test oe one eae gd Residual AM Test esidual FM Test 22 25 Output Level Accuracy Test 1000 4 26 Output Level Accuracy Test complete ETT uu Level Flatness Test ud 4 29 Dutput Impedance Test Broadband 4 30 Auxiliary Output Test 4 31 Qutput Leakage Test gt gt fro z AH X 1 i 1 L 1 lox los N c 14 33 Internal Modulation Oscillator 12 1 Ja D
54. US Army Communications and Electronics Materiel Readiness Command ATTN DRSEL ME MQ Fort Monmouth New Jersey 07703 FOLD BACK REVERSE OF DA FORM 2028 2 ANIT GALLOG AVAL PEN PERG OR HIE 1151 RECOMMENDED CHANGES TO EQUIPMENT TECHNICAL PUBLICATIONS SOMETHING WRONG wets tats PUBLICATION FROM PRINT YOUR UNIT S COMPLETE ADDRESS THEN JOT DOWN THE DOPE ABOUT IT ON THIS FORM CAREFULLY TEAR IT OUT FOLD IT AND DROP IT PUBLICATION NLIMBER PUBLICATION DATE PUBLICATION TITLE Signal Generators TM 11 6625 2780 11 31 Dec 80 50 1112 7 1 0 and SG 1112 V 2 U PIN POINT WHERE 1715 IN THIS SPACE TELL WHAT IS WRONG FIGURE TABLE AND WHAT SHOULD BE DONE ABOUT IT NO NO PRINTE GRADE OR TLE ANT TELEPHONE NUMBER SIGN HERE D FORM 2028 2 PREVIOUS EDITIONS PS AF YOUR OUTFIT WANTS KNOW ABOUT YOUR Four 79 ARE GASCLETE RECOMMENDATION MAKE A CARBON COPY OF THIS AND GIVE IT YOUR HEADQUARTERS FILL IN YOUR UNIT S ADDRESS FOLD BACK DEPARTMENT OF THE ARMY POSTAGE AND FEES PAID 5 DEPARTMENT OF THE ARMY Ee US MAIL OFFICIAL BUSINESS 505 314 PENALTY FOR PRIVATE USE 300 Commander US Army Communications and Electronics Materiel Readiness Command ATTN DRSEL ME MQ Fort Monmouth New Jersey 07703 FOLD BACK REVERSE OF DA FORM 2028 2 ANIT G31100 HV3 I AGONG LENG RECOMMENDED CHAN
55. 0757 0424 28480 5905 00 493 0736 08640 60177 28480 6625 00 521 2599 0757 0438 28480 5905 00 929 2529 08640 60190 28480 5961 01 007 1256 0757 0439 28480 5905 00 990 0303 08640 80002 28480 5950 01 005 9932 0757 0440 28480 5905 00 858 6795 08640 80003 28480 5985 00 524 1310 0757 0441 28480 5905 00 858 6799 1N821 4713 5961 00 866 5454 0757 0442 28480 5905 00 998 1792 10 471 24226 5950 00 961 9600 0757 0443 28480 5905 00 891 4252 109D336X0075F2 56289 5910 00 430 5953 PART NUMBER 200 0041 200 0043 200 0173 205 0011 205 0085 250 0257 250 0829 250 0830 250 0835 250 0914 251 1886 251 2026 251 2034 251 2313 490 0030 50D104X9035A2 50D105X9035A2 50D106X9020B2 50D156X9020B2 50D157X9006R2 50D224X9035A2 50D225X9020A2 50D225X9035B2 50D226X9015B2 50D227X9010S2 50D336X9010B2 50D337X9006S2 50D475X9035B2 50D606X9006B2 50D685X9035B2 820 0054 820 0055 PART NUMBER NATIONAL STOCK NUMBER TABLE 6 5 CROSS REFERENCE INDEX FSCM 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 56289 56289 56289 59289 56289 56289 56289 56289 56289 56289 56289 56289 56289 56289 56289 28480 28480 NATIONAL STOCK NUMBER 5935 00 971 9712 5970 00 805 7166 5999 00 008 7037 5999 00 789 3794 5999 00 412 0599 5935 00 497 5630 5935 00 428 2
56. 1 Connect equipment as shown Figure 4 26 with oscilloscope connected directly to test generator s RF OUT after setting test Signal Generator s controls as follows Meter Function LEVEL COUNTER MODE EXPAND won fece oue da LOCK off Source INT AM PULSE FM OFF RANGE sos a m 0 5 1 MHz FREQUENCY TUNE MHz OUTPUT LEVEL Switches 17 dBm OUTPUT LEVEL Vernier RF ON OFF ON 4 74 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 41 PULSE MODULATION TEST Control 2 Set pulse generator for a repetition rate of 100 Hz a pulse width of 10 and an amplitude of lv 3 Adjust oscilloscope to display the RF pulse envelope Readjust the pulse width for 10 us measured at 507 amplitude points and measure the rise and fall times se _Figure 4 27 Both should be less than 9 us measured between 10 and 90 of the full pulse amplitude Rise Time ____ OD us Fall Time ___ OD us lt RF PULSE P d ENVELOPE LEVEL ACCURACY RISE TIME FALL TIME Figure 4 27 Pulse Measurements 4 Set test Signal Generator s AM switch to OFF and adjust oscilloscope s vertical controls for 6 divisions of deflection on the display peak to peak 5 Set test Signal Generators AM switch to PULSE Pulse amplitude peak to peak
57. 10 2 1 A10A2TP2 A10A2TP3 10 2 4 10 201 2104202 10 203 10 204 10 205 A10A2U6 10 207 A10A2U8 A10A2U9 A10A2U10 A10A2U11 A10A2U12 A10A2U13 A10A2U14 A10A2U15 A10A2U16 A10A2U17 A10A2U18 A10A2U19 A10A2U20 A10A2VRl 10 2 1 A10A2W2 A10A2W3 A10A2WA A10A2W5 A10A2W6 A10A2WT7 A10A2XA10A2U5 A10A2XA10A2U9 A10A3 A10A3XA10A2A A10A3XA10A2B HP PART NUMBER 0757 0984 0757 0438 0698 7224 0698 7219 0698 7190 0698 7227 0698 7227 0757 0399 0698 3437 0757 0984 0757 0438 0757 0984 0757 0438 0757 0984 0698 7253 0698 7253 0698 3440 0698 3444 0757 0379 0698 3447 0698 3447 0757 0442 0757 0984 0757 0442 0698 0085 0757 1094 0698 3454 0757 0442 0757 0280 0757 0280 0757 0416 08553 6012 08553 6012 08553 6012 08553 6012 08553 6012 08640 80002 0360 1514 0360 1514 0360 1514 0360 1514 1826 0013 1820 0102 1820 0102 1820 0102 1820 0102 1820 0535 1820 0145 1820 0145 1820 0145 1820 0753 1820 0982 1820 0736 1820 0753 1820 1354 1820 0753 1820 0557 1820 0145 1820 0143 1820 0145 1820 0102 1902 3002 8120 1823 8120 1824 8120 1825 8120 1826 8120 1828 8120 1827 8120 1829 1200 0474 1200 0474 08640 60022 1251 2035 1251 2026 QTY 19 TABLE 6 3 REPLAC DESCRIPTION RESISTOR 10 OHM 1 RESISTOR 5 11K 1 RESISTOR 316 OHM RESISTOR 196 OHM EABLE PARTS 5W F TUBULAR 125W F TUBULAR 2 05W F TUBULAR 2 05W
58. 125W F TUBULAR 19701 MF4C1 4 T9 3001 C A9R17 0698 5669 RESISTOR 1 5K 25 125W F TUBULAR 19701 MF4C1 8 T9 1501 C A9R18 0698 8213 RESISTOR 3K 25 125W F TUBULAR 19701 MF4C1 4 T9 3001 C A9R19 0698 5669 RESISTOR 1 5K 25 125W F TUBULAR 19701 MF4C1 8 T9 1501 C A9R20 0698 8213 RESISTOR 3K 25 125W F TUBULAR 19701 MF4C1 4 T9 3001 C A9R21 0698 5669 RESISTOR 1 5K 25 125W F TUBULAR 19701 MF4C1 8 T9 1501 C A9R22 0698 5669 RESISTOR 1 5K 25 125W F TUBULAR 19701 MF4C1 8 T9 1501 C A9R23 0698 8299 RESISTOR 4 259K 25 125W F TUBULAR 19701 MF4C1 8 T9 4259R C A9R24 0698 8298 RESISTOR 1 071K 25 125W F TUBULAR 19701 MF4C1 8 T9 1071R C A9R25 0698 8297 RESISTOR 1 28K 25 125W F TUBULAR 19701 MF4C1 8 T9 1284R C A9R26 0757 0398 RESISTOR 75 OHM 1 125W F TUBULAR 24546 C4 1 8 TO 75R0 F A9R27 0698 8296 RESISTOR 1 49K 25 125W F TUBULAR 19701 MF4C1 8 T9 1493R C A9R28 0757 0399 RESISTOR 82 5 OHM 1 125W F TUBULAR 24546 C4 1 8 TO 82R5 F A9R29 0698 8295 RESISTOR 1 556K 25 125W G TUBULAR 19701 MF4C1 8 T9 1556R C A9R30 0757 0400 RESISTOR 90 9 OHM 1 125W F TUBULAR 24546 C4 1 8 TO 90R9 F A9R31 0757 0400 RESISTOR 90 9 OHM 1 125W F TUBULAR 24546 C4 1 8 TO 90R9 F A9S1 NSR PART OF A9 952 NSR PART OF A9 A9S3 NSR PART OF A9 AQW1 08640 60107 CABLE ASSY PEAK DEVIATION 28480 08640 60107 A10 08640 60105 15 DIVIDER FILTER ASSY 28480 08640 60105 10 1 0403 0156 2 GUIDE BOARD YELLOW 28480 0403 0156 10 2 0403 0157 2 GUIDE BOARD GREE
59. 15 0698 0082 2 11 16 0757 0200 2 11 17 0757 0442 11 18 0757 0401 11 19 0757 0395 5 Al1R20 0757 0401 A11R21 0757 0395 A11R22 0757 0395 A11R23 0757 0346 4 Al1R24 0757 0346 Al1R25 0757 0442 A11R26 0698 3156 2 11 27 0757 0280 2 A11R28 0698 3132 1 Al1R29 A11R30 0757 0346 A11R31 0757 0346 A11R32 0757 0280 11 33 0698 3453 Al1R34 0698 3152 1 Al1R35 2100 2521 2 Al1R36 0757 0290 1 A11R37 0757 0279 A11R38 0757 0199 Al1R39 0698 3150 1 A11R40 2100 2521 11 41 0698 0082 Al1RA42 0757 0200 A11R43 0757 0401 A11R44 0757 0401 11 45 0757 0442 A11R46 0757 0401 Al1RA47 0757 0401 A11R48 0698 3156 Al1RA49 0698 0024 2 A11R50 0698 0024 A11R51 0757 0395 Al1R52 0757 0395 Al1R53 0757 1100 2 Al1R54 0757 1100 Al1R55 0757 0442 Al1R56 0757 0442 11 1 5080 1718 1 11 1 0360 1514 6 11 2 0360 1514 11 0360 1514 11 0360 1514 11 5 0360 1514 11 6 0360 1514 A11VR1 1902 3059 2 Al1VR2 1902 3059 11 1 08640 601491 11 1 1 08640 202181 11 1 2 08640 202051 11 1 1430 0763 1 11 1 4 08640 20084 1 11 1 5 3030 0196 1 11 1 3030 0007 1 11 1 1 0698 4471 2 A11A1R2 0757 0199 A11A1R3 0698 3454 2 11 1 4 0698 5903 2 11 1 5 0698 4471 TABLE 6 3 DESCRIPTION REPLACEABLE PARTS RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 200K 1 125W F TUBULAR 100 OHM 1 125W F TUBULAR 100 OHM 1 125W F TUBULAR 8 25K 1 125W F TUBULAR 16 2K 1 125W F
60. 20 500WVDC CER 28480 0160 3219 A26C5 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C6 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C7 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C8 0160 2049 CAPACITOR FXD 5000PF 80 20 5000WVDC CER 28480 0160 2049 A26C9 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C10 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C11 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C12 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C13 0160 3961 1 CAPACITOR FXD 56PF 20 500WVDC CER 28480 0160 3961 A26C14 0160 3219 CAPACITOR FXD 100PF 20 200WVDC CER 28480 0160 3219 A26C15 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C16 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C17 0160 2152 2 CAPACITOR FXD 10PF 20 500WVDC CER 28480 0160 2152 A26C18 0160 2152 CAPACITOR FXD 10PF 20 500WVDC CER 28480 0160 2152 A26J1 1250 0829 1 CONNECTOR RF SMC M SGL HOLE FR 98291 50 045 4610 A26L1 9100 1620 COIL FXD MOLDED RF CHOKE 15UH 10 24226 15 152 A26L2 9100 1621 1 COIL FXD MOLDED RF CHOKE 18UH 10 24226 15 182 A26L3 9100 1620 COIL FXD MOLDED RF CHOKE 15UH 10 24226 15 152 A26L4 9100 1620 COIL FXD MOLDED RF CHOKE 15UH 10 24226 15 152 A26L5 9100 1620 COIL FXD MOLDED RF CHOKE 15UH 10 24226 15 152 A26L6 9100 1620 COIL FXD
61. 24546 28480 288480 28480 28480 28480 REPLACEABLE PARTS MFR PART NUMBER 1902 0049 3 332070 5 3 332070 5 3 332070 5 3 332070 5 08640 60177 150D336X9010B2 0160 3534 292P56292 30D506G025CC2 150D336X9010B2 0160 3534 292P56292 30D506G025CC2 1901 0025 SR1358 4 1901 0050 1901 0025 1901 0050 SR1358 4 1990 0326 1990 0326 GMW 3 4A GMW 3 4A 4040 0748 OBD 4040 0754 OBD 2N3528 1854 0232 1200 0173 1854 0232 1200 0173 2N3528 C4 1 8 TO 2611 F C4 1 8 TO 1001 F C4 1 8 TO 4221 F C4 1 8 TO 101 F C4 1 8 TO 2151 F C4 1 8 TO 5111 F 3006P 1 501 CB27G5 C4 1 8 TO 178R F C4 1 8 TO 68R1 F C4 1 8 TO 422R F BWH2 1R5 J C4 1 8 TO 1781 F C4 1 8 TO 2611 F C4 1 8 TO 1001 F C4 1 8 TO 4221 F C4 1 8 TO 101 F C4 1 8 TO 5111 F 3006P 1 501 C4 1 8 TO 2151 F CB27G5 C4 1 8 TO 178R F C4 1 8 TO 68R1 F C4 1 8 TO 422R F BWH2 1R5 J C3 1 8 TO 1002 G C3 1 8 TO 1002 G C4 1 8 TO 1781 F 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 MODEL 8640B OPTION 004 REPLACEABLE PARTS TABLE 6 3 REPLACEABLE PARTS REFERENCE HP PART QTY DESCRIPTION MFR MFR PART NUMBER DESIGNATION NUMBER CODE A22TP6 0360 1514 TERMINAL SLDR STUD 28480 0360 1514 A22TP7 0360 1514 TERMINAL SLDR STUD 28480 0360 1514 A22TP8 0360 1514 TERMINAL SLDR STUD 28480 0360 1514 A22TP9 0360 1514 TERMINAL SLDR STUD 28480 0360 1514 A22U1 1826 0177 IC LIN REGULATOR 15818 723BE A22U2 1826 0177 IC LIN REGULATOR 15818 723BE A22VR1 1902 02
62. 28480 24226 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 16299 24546 24546 24546 24546 24546 24546 24546 16299 24546 24546 24564 24546 24546 24546 REPLACEABLE PARTS MFR PART NUMBER 0160 3094 0160 2055 0160 2055 0160 2055 0160 2055 0160 2055 0160 2055 0160 3094 0160 3879 0160 2055 0160 3094 0160 2055 0160 3879 0160 3879 0160 3877 0160 3877 0160 3457 0160 3456 0160 3094 0160 2055 150D225X9020A2 150D225X9020A2 150D225X9020A2 150D225X9020A2 150D225X9020A2 0160 3094 0160 2055 150D225X9020A2 150D225X9020A2 150D225X9020A2 150D225X9020A2 0160 2055 150D225X9020A2 0160 3456 1901 0040 1250 1383 19 104 19 104 19 104 19 104 19 104 19 104 19 104 19 104 19 104 08640 80001 19 104 08640 80001 08640 80001 08640 80001 2190 0003 2200 0155 2260 0001 08640 20211 08640 40040 1854 0019 1854 0019 C4 1 8 TO 4641 F C4 1 8 TO 1213 F C4 1 8 TO 1002 F C4 1 8 TO 5111 F C3 1 8 TO 511R G C4 1 8 TO 511R F C4 1 8 TO 1002 F C4 1 8 TO 1002 F C4 1 8 TO 2611 F C4 1 8 TO 3161 F C4 1 8 TO 511R F C4 1 8 TO 511R F C4 1 8 TO 5111 F C4 1 8 TO 5111 F C4 1 8 TO 5111 F MODEL 8640B OPTION 004 REFERENCE DESIGNATION A8A3R16 A8A3R17 A8A3R18 A8A3R19 A8A3R20 A8A3R21 A8A3R22 A8A3R23 A8A3S1A A8A3S1B A8A3S1C A8A3TP1 A8A3U1 A8A3U2 A8A3U3 A8A3U4 A8A3U5 A8A3U6 A8A3U7 A8A3U8 A8A3U9 A8A3U10 A8A3U11 A8A3U12 A8A3U13 A8A3U14
63. 3 Output Level 20 mVrms to 3 Vrms into 600 Q Total Harmonic Distortion lt 0 25 400 Hz and 1 kHz fixed tones lt 0 5 20 Hz to 2 kHz lt 1 0 2 kHz to 600 kHz Amplitude Modulation Not applicable when OUTPUT LEVEL 10 dB switch 16 dBm position Depth 0 to 100 AM Rates INT and EXT ac 20 Hz to AM 3 dB band width EXT dc dc to AM 3 dB bandwidth AM is possible in tbe 16 dBm output range with AM depths typically up to 50 however DEMOD OUTPUT is not cali brated 1n this range and degradation of other AM specifications should be expected AM 3 dB Bandwidth Se Figure 1 4 Frequency Bands 0 5 2 MHz 2 8 MHz 8 512 MHz Model 8640B Option 004 General Information Table 1 1 Specifications 4 of 6 MODULATION CHARACTERISTICS Cont d Amplitude Modulation Cont d AM Distortion at 400 Hz and 1 kHz rates Frequency Oto 50 to Bands 50 AM 90 AM External AM Sensitivity 400 Hz and 1 kHz rates 0 100 0 005 AM per inV peak into 6002 with AM vernier at full cw position indicated AM Accuracy 400 Hz and 1 kHz rates using internal meter 8 of reading on 0 10 scale 9 of reading on 0 3 scale for greater than 10 of full scale Peak Incidental PM at 30 AM Less than 0 15 radians 0 5 to 128 MHz Less than 0 3 radians 128 to 512 MHz Peak Incidental Frequency Deviation Equals PEAK INCIDENTAL PM x MODULATION RATE Demodulated Output OUTPUT LEVEL ve
64. 70 lt ANODE AXMBOSCHLATOR P ASSY a Aa LOOP ASSY _ FL3 NM d fi pa 1 Ee 1 a 1 4 i P O XA3A4 20V 8 o 0225 Ww FL4 NO PREFIX P O W2 W3 i i m Bi DELETED A3A4R6 m 27 1 RF DIVIDER FILTER BUFFER AMPLIFIER BOARD ASSY 08640 60024 NOTES litum E F5 SEE BACKDATING 7 2 28 27 1 EE o s I gt i w3 E 10 pus 2c REFERENCE DESIGNATIONS WITHIN OUTLINED lt 9 l ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER e g RI OF ASSEMBLY 15 AIRI DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS SHOWN Fog i i L RF OSCILLATOR 86408 OPTIGH OM 1473A SIN eee eee eee 8 Ore Figure 8 23 RF Oscillator Simplified Diagram 8 27 SERVICE SHEET 6 PRINCIPLES OF OPERATION General The A5 FM Amplifier Assembly in conjunction with the A9 Peak Deviation and Range Switch and the A7 Shaping Assembly conditions the modulation signal to drive the varactor diodes which frequent y modulate the RF oscillator Modulation signals may be dc or ac coupled Input and Buffer Circuits A5 The FM modulating signal is applied to the Deviation Vernier which presents a 600 impedance to the modulation source Buffer Amplifier
65. 8150 0498 2 8120 1881 1 8120 1882 8120 0580 8150 0447 8150 0496 8150 0498 TABLE 6 3 REPLACEABLE PARTS DESCRIPTION KNOB AND SKIRT FREQUENCY TUNE NOT ASSIGNED BOARD ASSY EXTENDER BUTTON X10 BUTTON 507 Z BUTTON VOLTS SCREW SET 4 40 SMALL CUP PT HEX REC ALY FRONT PANEL KNOBS SCREW TPG 6 20 PAN SCREW TPG 6 20 PAN INSULATOR XSTR TC 3 02 THK FAN BLADE 76 THK 3 OD 079 ID GUIDE PLUG IN PC BOARD SCREW SET 4 40 SMALL CUP PT HEX REC ALY FOOT REAR LONG NOT ASSIGNED HEAT SINK TRANSISTOR CECK TRANSFORMER DECK MAIN NOT ASSIGNED GROMMET RUBBER FOR 0 562 DIA HOLE GLIDE NYLON RFI RING MNL 75 OD 218 ID 4 L MAIN TUNE RFI RING MNL 63 OD 12 ID 2 L FINE TUNE COLLAR RETAINING FINE TUNE SHAFT LEVER SLIDE SWITCH INSULATOR TRANSISTOR KNOB ASSY OUTPUT LEVEL 1 DB KNOB ASSY OUTPUT LEVEL 10 DB SHAFT BUSHING PANEL 3 8 52 THD BRASS NOT ASSIGNED BRACKET FAN TOP BRACKET FAN BOTTOM FOAM STRIP BOTTOM COVER LABEL DEMOD CAL NOT ASSIGNED KNOB TIME BASE SCREW SET 4 40 SMALL CUP PT HEX REC ALY CONNECTOR PC EDGE 10 CONT SOLDER EYE CONNECTOR PC EDGE 6 CONT SOLDER EYE HOOD CONNECTOR PLZG KEY PRINTED CIRCUIT CONN CONTACT CONN U W MICRO SER FEM CONNECTOR STRIP 9 OPEN POSITION TRANSISTOR NPN 2N3055 SI PD 115W TRANSISTOR NPN 2N3055 SI PO 115W TRANSISTOR NPN SI 0 3 PD 115W TRANSISTOR NPN 2N3055 SI PD 115W TRANSISTOR NPN 2N3055 SI PD 115W RESISTOR VAR CN
66. A10A1C51 0160 3936 A10A1C52 0160 3156 A10A1C53 0140 0234 A10A1C54 0160 2307 A10A1C55 0160 0974 A10A1C56 0160 0974 A10A1C57 0160 2201 A10A1C58 0160 2306 A10A1C59 0160 2201 A10A1C60 0160 2201 A10A1C61 0160 2199 A10A1C62 0160 0335 A10A1C63 0140 0177 A10A1C64 0140 0234 A10A1C65 0140 0233 A10A1C66 0160 3934 A10A1C67 0160 2537 A10A1C68 0160 3046 A10A1C69 0160 2265 A10A1C70 0140 0190 10 1 71 0140 0190 A10A1C72 0160 2266 A10A1C73 0160 2260 A10A1C74 0160 2266 A10A1C75 0160 2266 A10A1C76 0160 2262 10 1 77 0160 2257 A10A1C78 0160 2263 A10A1C79 0160 2263 A10A1C80 0160 2257 A10A1C81 0121 0060 A10A1C82 0121 0061 A10A1C83 0121 0061 A10A1C84 0121 0060 A10A1C85 0160 0174 QTY NWN TABLE 6 3 REP DESCRIPTION CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR F
67. A18R8 A18R9 A18R10 A18R11 A18R12 A18R13 A18R14 A18R15 A18R16 A18R17 A18R18 A18R19 18 1 18 2 A18TP3 18 4 18 5 18 6 1801 A18VR1 A18VR2 A18VR3 A18XF1A 18 A19 A19 19 1 19 2 A19MP3 19 4 19 5 19 6 1951 1951 19 1 A19A1C1 A19A1J1 A19A1J2 A19A2 19 2 1 A19A2R2 A19A2R3 19 2 4 A19A2R5 A19A2R6 A19A2R7 A19A2R8 A19A2R9 A19A2TP1 A19A2TP2 A20 HP PART NUMBER QTY 1853 0050 1853 0050 1853 0027 1200 0173 1853 0050 1853 0027 1200 0173 0757 0317 2100 3123 0757 0278 0683 0475 1 0757 0420 0698 3440 0757 0420 0698 3161 0811 2813 3 0757 0316 0757 0317 0757 0397 5 0698 3447 0757 0290 0757 0442 0811 1553 1 0698 3438 0698 3438 0698 7246 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 1826 0177 5 1902 3005 2 1902 3094 1 1902 0049 1251 2313 10 1251 2313 08640 600601 08640 60078 0380 0020 0380 0072 0550 0053 1500 0382 2190 0020 HENN 2360 0119 2 3130 0446 1 3130 0445 1 08640 600611 08640 600541 0757 0420 0757 0279 0698 3150 0757 0442 0698 3449 0757 0280 2100 2521 2100 2521 0698 3447 0360 1514 0360 1514 08640 600051 TABLE 6 3 DESCRIPTION REPLACEABLE PARTS TRANSISTOR PNP TRANSISTOR PNP TRANSISTOR PNP INSULATOR XSTR TRANSISTOR PNP SI CHIP SI CHIP SI CHIP TO 39 TO 5 075 THK SI CHIP TO 18 PD 360MW
68. A2TPS 0360 1514 TERMINAL SLDR STUD 28480 0360 1514 A2U1 1820 0158 3 IC LIN LM302 FOLLOWER 27014 LM302H A2U2 1820 0476 1 IC LIN AMPLIFIER 07263 715HC REPLACEABLE PARTS REFERENCE DESIGNATION A2VR1 A2VR2 A3 A3 1 2 A3L1 A3MP1 A3MP2 A3MP3 A3MP4 A3MP5 A3MP6 A3MP7 A3MP8 A3MP9 A3MP10 A3MP11 A3MP12 A3MP13 A3MP14 A3MP15 A3MP16 A3MP17 A3MP18 A3MP19 A3MP20 A3MP21 A3MP22 A3MP23 A3MP24 A3MP25 A3MP26 A3Q1 A3R1 A3R2 1 1 1 A3A1FL2 A3A1FL3 A3A1FL4 A3AlFL5 A3AlFL6 1 1 A3A1J2 A3A1MP1 A3A1MP2 A3A1MP3 1 4 1 5 1 6 A3A1MP7 A3A1MP8 A3A1MP9 A3A1MP10 A3A1MP11 A3A1MP12 A3A1MP13 A3A1MP14 A3A1MP15 A3A1MP16 1 1 HP PART NUMBER 1902 3104 1902 0025 08640 60099 08640 60098 0510 0052 0510 0055 1430 0537 1430 0759 08640 00085 08640 20106 8160 0233 08640 20106 08640 20224 08640 60206 2200 0151 2190 0019 8160 0203 0510 0055 3030 0007 1430 0759 3030 0196 2190 0016 3030 0196 2190 0016 3030 0007 2510 0135 3050 0001 2190 0017 08640 20193 0510 0015 5086 7082 2100 3265 2100 0541 0160 0204 0160 0204 0160 0204 0160 0204 0160 0204 0160 0204 1250 0830 1250 0830 08640 00011 2200 0105 3050 0105 8160 0229 08640 00011 8160 0229 2200 0105 3050 0105 2740 0001 2190 0011 2740 0001 2190 0011 2200 0121 2190 0019 2190 0019 2200 0143 QTY
69. BG027 16299 24546 16299 24546 24546 24546 24546 16299 24546 24546 24546 24546 03888 03888 03888 03888 24546 24546 24546 24546 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 19701 19701 19701 19701 28480 REPLACEABLE PARTS MFR PART NUMBER 08640 60020 0160 3548 0160 0336 30D107G025DD2 30D107G025DD2 150D606X900682 150D156X9020B2 150D156X9020B2 1901 0040 1901 0040 1901 0040 1854 0003 1200 0173 1854 0003 1200 0173 1854 0071 1854 0003 1200 0173 1854 0003 1200 0173 1854 0071 C4 1 8 TO 10R0 F C4 1 8 TO 5111 F MF4C1 8 TO 3163 F C4 1 8 TO 2611 F CT 106 4 C4 1 8 TO 2871 F C4 1 8 TO 1001 F C4 1 8 TO 1963 F C4 1 8 TO 1001 F C4 1 8 TO 5111 F C4 1 8 TO 5111 F C4 1 8 TO 5111 F C4 1 8 TO 2611 F C4 1 8 TO 101 F C4 1 8 TO 101 F C4 1 8 TO 101 F C4 1 8 TO 101 F PME65 1 2 TO 2611 E PME65 1 2 TO 2611 F PME65 1 2 TO 2611 F PME65 1 2 TO 2611 F C4 1 8 TO 601 F C4 1 8 TO 601 F C4 1 8 TO 1002 F C4 1 8 TO 1002 F 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 1826 0007 1902 0049 1902 0049 08640 60116 08640 20218 MF4C1 8 TO 1573 F MF4C1 8 TO 3923 F MF4C1 8 TO 1573 F MF4C1 8 TO 3923 F 3100 3091 MODEL 8640B OPTION 004 REFERENCE DESIGNATION All 11 1 A11C2 11 3 11 4 11 5 11 6 11 7 11 8 11 9 11 10 11 11 A11C12 A11C13 11 14 11 15 11
70. COIL FXD MOLDED RF CHOKE 1MH 5 COIL FXD MOLDED RF CHOKE 1MH 5 COIL FXD MOLDED RF CHOKE 1MH 5 COIL FXD MOLDED RF CHOKE 1MH 5 COIL FXD MOLDED RF CHOKE 1MH 5 COIL FXD MOLDED RF CHOKE 1MH 5 COIL FXD MOLDED RF CHOKE 1MH 5 COIL FXD HOLDED RF CHOKE IMH 5 TORDID FILTER COIL FXD MOLDED RF CHOKE UMH 5 TOROID FILTER TOROID FILTER TOROID FILTER WASHER LK HLCL NO 4 115 IN ID 253 IN SCREW MACH 4 40 PAN HD POZI REC SST 300 NUT HEX DBL CHAM 4 40 THD 094 THK 25 GUIDE CONNECTOR INSULATOR SWITCH TRANSISTOR NPN SI TO 18 PD 360MW TRANSISTOR NPN SI TO 18 PD 360MW RESISTOR 4 6K 1 125W F TUBULAR RESISTOR 1 21K 1 125W F TUBULAR RESISTOR 10L 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 511 OHM 2 05W F TUBULAR RESISTOR 511 OHM 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR RESISTOR 2 61K 1 125W F TUBULAR RESISTOR 3 16K 1 125W F TUBULAR RESISTOR 511 OHM 125W F TUBULAR RESISTOR 511 OHM 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR MFR CODE 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 56289 56289 56289 56289 56289 28480 28480 56289 56289 56289 56289 28480 56289 28480 28480 28480 24226 24226 24226 24226 24226 24226 24226 24226 24226
71. Counter U14 then increments by one more count This process continues until both counters reach a count of nine Counter U14 then generates a high carry which enables the load inputs via inverter The next clock pulse presets the counter The count sequence is then repeated The total count equals 9 preset count of U14 x 10 10 preset count of 013 The preset count is determined by the range section of the switch 952 and the COUNTER MODE switches In the INT mode the COMMON switch line is low gates U1A U1B U8B and U8D decode the band code lines CODE B and CODE C and preset the data inputs of U13 and U14 In the EXT mode the COMMON line is high and CODE B and CODE C are high The data inputs of U13 and U14 for different count conditions are given in 8 7 Note that band CODE A is defined as high on both CODE B and CODE C SERVICE SHEET 19 Cont d Table 8 6 Total Count of Time Base Reference Counters U13 U14 and U15 Tota Count Division COUNTER MODE Band Code Range MHz 8 1 25 5 125 9 20x 1 25 4 25 2 50 8 25 4 100 6 25 x 8 200 16 32 40 x 1 40 32 64 40 x 2 80 64 128 A0 x 4 160 128 256 82x 1 32 256 512 32x 2 64 512 1024 32 x4 128 32x2 04 25x4 100 The Qp output of U14 drives inverter U7F which drives counter U15 and OR gate UBB Counter U15 is a programmable 1 2 4 5 or 8 counter its operation is similar to that of U13 and U14 At the last count
72. DESCRIPTION CAPACITOR FXD NOT ASSIGNED CA ACOTPR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 01UF 80 20 100WVDC CER lUF 10 100WVDC CER CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 1UF 10 100WVDC CER CAPACITOR FXD 01UF 20 100WVDC CER CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 1UF 10 100WVDC DC CER CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 01UF 20 100WVDC CER CAPACITOR FXD 01UF 20 100WVDC CER CAPACITOR FXD 100 20 200WVDC CER CAPACITOR FXD 100 20 200WVDC CER CAPACITOR FXD 2000RF 10 250WVDC CER CAPACITOR FXD 1000PF 10 100CWVDC CER CAPACITOR FXD 1UF 10 100WVDC CER CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD 010 80 20 100WVDC CER 2 2UF 10 20VDC TA 2 2UF 10 20VDC TA 2 2UF 10 20VDC TA 2 20 10 20VDC CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD 2 2UF 10 20VDC TA lUF 4 10 100WVDC CER 010 80 20 100WVDC CER 2 2UF 10 20VDC TA 2 2UF 10 20VDC TA CAPACITOR FXD 2 20 10 20VDC CAPACITOR FXD 2 2UF 10 20VDC TA CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 2 2 0 10 20VDC CAPACITOR FXD 1000PF 10 1000WVDC CER DIODE SWITCHING 2N2 30V 50MA CONNECTOR RF SN SNP M SGL HOLE RR COIL FXD MOLDED RF CHOKE 1MH 5
73. DIODE GEN PRP 180V200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA DIODE GEN PRP 180V 200MA CONNECTOR RF SMC M PC RELAY REED 1C 25A 150V CONT 5V COIL MODEL 8640B OPTION 004 MFR CODE 24546 24546 16299 16299 24546 24546 19701 19701 01121 01121 19701 28480 28480 28480 28480 28480 28480 27014 28480 00501 00501 00501 00501 00501 00501 74868 90949 13521 24546 28480 56289 56289 56289 56289 56289 56289 84411 56287 28480 56289 56289 28480 56289 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 24931 28480 MFR PART NUMBER C4 1 8 T0 1002 F C4 1 8 TO 5111 F C4 1 8 TO 2611 F C4 1 8 TO 2611 F C4 1 8 TO 82R5 F C4 1 8 TO 82R5 F MF7C1 2 T0 21R5 F MF7C1 2 T0 101 F CB91G5 CB91G5 MF4C1 8 T0 4643 F 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 LM302H 08640 60033 LA 851 LA 851 LA 85
74. DM15F201F0300WV1CR DM15F131J0300WV1CR DM15F201F0300WV1CR DM15F201F0300WV1CR DM15F131J0300WV1CR 0160 3156 0160 3940 0160 2587 0160 4217 0160 2276 DM19F302F0100WV1CR 0160 2585 0160 2537 0160 0341 0160 0341 DM15F391J0300WV1CR DM15F241J0300WV1CR 0160 0939 0160 0939 DM15F241J0300WV1CR 0160 2537 0160 3092 0160 2585 0160 3937 0160 3939 0160 3938 0160 2387 0160 0335 0160 2206 0160 2206 0160 2204 DM15E62030300WV1CR 0160 0839 0160 0839 DM15E62030300WV1CR DM15F181G0300WV1CR 0160 0342 0160 2387 0160 3835 0160 3936 0160 3156 DM15F501F0300WV1C 0160 2307 0160 0974 0160 0974 0160 2201 0160 2306 0160 2201 0160 2201 0160 2199 0160 0335 DM15F401F0300WV1CR DM15F501F0300WVIC DM15F481F0300WV1C 0160 3934 0160 2537 0160 3046 0160 2265 DM15E39030300WV1CR DM15E390J0300WV1CR 0160 2266 0160 2260 0160 2266 0160 2266 0160 2262 0160 2257 0160 2263 0160 2263 0160 2257 DV11PS8A DV11PS18A DV11PS18A DV11PS8A 0160 0174 MODEL 08640B OPTION 004 REFERENCE DESIGNATION A10A1C86 A10A1C87 A10A1C88 A10A1C89 A10A1C90 A10A1C91 10 1 1 10 1 1 2 A1OA1FL3 A1OA1J1 A10A1J2 A10A1J3 A10A1JA4 10 1 1 10 1 2 10 1 10 1 4 10 111 10 112 10 113 10 114 10 115 10 116 10 117 10 118 10 119 10 1110 10 1111 10 1112 10 1113 10 1114 10 1115 10 1116 10 1117 10 1118 10 1119 A10A1L20 10 1121 A
75. Digital Voltmeter HP 3480D 3484A Option 043 Frequency Counter 33276 Spectrum Analyzer HP 7141 8552 8553 Reference Signal Generator HP 8640A Mixer oe 7529 we co IS we Ao OR 9 HP 10514 NOTE The reference signal generator should have frequency drift and residual FM specifications equivalent to the HP Model 8640 PROCEDURE 1 Connect equipment as shown in Figure 4 30 with test Signal Generator connected to mixer and mixer connected to analyzer after setting test generator s controls as follows Meter Function FM COUNTER MODE EXPAND a e off LOCK ao d ce Source s a s E INT 4 82 Model 83640B Option 004 Performance Tests PERFORMANCE TESTS 4 45 FM SENSITIVITY AND ACCURACY TEST Cont d 4 PEAK DEVIATION 2 5kHz PEAK DEVIATION Vernier Fully CW RANGE 2 2 25 2 256 512 MHz FREQUENCY TUNE 512 MHz OUTPUT LEVEL Switches 7 dBm OUTPUT LEVEL Vernier CAL RE ON OEE Set reference signal generator for a 513 MHz CW signal at 13 dBm Set spectrum analyzer s center frequency controls to 1 MHz input attenuation to 20 dB resolution bandwidth to 0 1 kHz span width per division scan width to 1 kHz and set display to 10
76. MOLDED RF CHOKE 15UH 10 24226 15 152 A26L7 9140 0178 1 COIL FXD MOLDED RF CHOKE 12UH 10 24226 15 122 A26L8 9100 1620 COIL RXD MOLDED RF CHOKE 15UH 10 24226 15 152 A26MP1 8160 0218 1 RFI STRIP NI ALY 782 W 4 728 L 28480 8160 0218 A26MP2 8160 0222 1 RFI STRIP NI ALY 2 027 W 3 053 L 28480 8160 0222 A26MP3 8160 0223 1 RFI STRIP NI ALY 1 W 2 196 L 28480 8160 0223 26 4 8160 0224 1 GASKET MOD BOTTOM COVER 28480 8160 0224 A26MP5 08640 000121 COVER ACCESS 28480 08640 00012 A26MP6 08640 000181 COVER FILTER MODULE 28480 08640 00018 A26MP7 08640 202621 COVER TOP MODULE 28480 08640 20 A26MP8 08640 202631 CASTING MODULE 28480 08640 20 A26MP9 08640 202641 COVER BUTTOM MODULE 28480 08640 20 A26MP10 08640 000131 COVER FILTER AMPLIFIER 28480 08640 00013 A26MP11 0403 0153 GUIDE C BOARD BROWN 28480 0403 0153 A26MP12 0403 0156 GUIDE P C BOARD YELLOW 28480 0403 0156 A26MP13 0403 0157 GUIDE P C BOARD GREEN 28480 0403 0157 A26MP14 2200 0107 SCREW MACH 4 40 PAN HD POZI REC SST 300 28480 2200 0107 A26MP15 0520 0127 SCREW PACH 2 56 PAN HD POZI REC SST 300 28480 0520 0127 MODEL 8640B OPTION 004 REFERENCE DESIGNATION A26MP16 A26MP17 A26MP18 A26MP19 A26MP20 A26MP21 A26MPC22 A26MP23 A26MP24 A26MP25 A26MP26 A26R1 A26U1 A26U1C1 A26U1C2 A26U1C3 A26U1CR1 A26U1R1 A26U1R2 A26U1R3 A26U2 A26W1 A26W2 A26W3 2614 26 1 A26A1C1 A26A1C2 A26A1C3 A26A1C4 A26A1C5 A26A1C6 26 1 1 26 1
77. Model 8640B Option 004 Service Table 8 4 Schematic Diagram Notes 3 of 3 Test point symbols Stars are numbered or lettered for easy correlation Interconnection information of schematic diagrams procedures and locator illustrations Circled letter indicates circuit Arrow connecting star to meas Star shown electrically con path continues on another urement point signifies no nected to circuit signifies meas schematic diagram Look for measuring aid provided Assembly part number Assembly name Assembly designation Stage name Circuit board common Conducting connection to chassis or frame Value selected for best operation Value shown is average or most commonly selected value Wire color code Code used MIL STD 681 is the same as the resistor color code First number iden tifies the base color second number the wider stripe and the third number the narrower stripe Example denotes white base yellow wide stripe violet narrow stripe uring aid metal post circuit same circled letter on service pad etc provided sheet indicated by adjacent bold number 3 in th s example Plug in connection information Socket designation for A2 assembly Number indicates pin of socket XA2 J3 not mounted poc EDU qos A2 DC REGULATOR ASSY 08708 60007 on assembly A2 TUS Tm mad 46 Non plug in connection information Solder point numbered DELETED Connector symbols w
78. NOTE EXPAND X10 and EXPAND 00 buttons are interlocked so that only one button can be depressed at a time LOCK phase locks Signal Generator to the internal or to an external crystal reference Display indicates lock frequency loss of lock causes display to flash and indicate actual frequency of Signal Generator INT programs counter to count frequency of signal Generator EXT 0 10 EXT 0 550 programs counter to count frequency of signal at COUNTER INPUT jack also selects counter frequency range in MHz Frequency MHz counter readout indicates RF frequency in MHz Flashing display indicates loss of phase lock The OVERFLOW lamp lights to indicate that significant data is not being dis played TIME BASE VERNIER used as a fine frequency tune when in lock mode to give continuous tuning between lock points the use of the COUNTER MODE EXPAND X10 control is necessary on some ranges to tune over the full range When control is not in CAL position the UNCAL lamp lights to indicate that the counter is uncalibrated OUTPUT LEVEL VERNIER varies RF amplitude over a 2 dB range from a CAL detent position also see DEMOD OUTPUT OUTPUT LEVEL 1 1 steps 0 to 12 dB OUTPUT LEVEL 10 dB 130dBm 10 dBm and a 6 dB step to 16 dBm On OFF enables or disables the RF output NOTE The RF ON OFF switch may be wired to turn off only the amplitude mod ulator This allows the RF oscill
79. Oscillator Adjustment 5 26 or Variable Frequency Modulation Oscillator Adjustment 5 27 Power Supply Adjustments 5 25 Power Supply Adjustments 5 25 Output Level Vernier and Meter Adjustment 5 30 Check power supply voltages 5 25 RF Detector Offset Adjust ment 5 29 Output Level Vernier and Meter Adjustment 5 30 Preliminary AM Adjustments 5 31 Model 864013 Option 004 Adjustments Table 5 2 Post Repair Test and Adjustments 4 of 4 Assembly Repaired Performance Tests Adjustments A26 AM AGC and RF Output Impedance Test AM Accuracy Adjustment Amplifier Assy Cont d 4 28 or 4 29 5 32 Auxiliary Output Test 4 30 Output Leakage Test 4 31 AM 3 GB Bandwidth Test 4 34 AM Distortion Test 4 35 AM Sensitivity and Accuracy Test 4 36 Peak Incidental Phase Modula tion Test 4 37 Demod Output Accuracy Test 4 38 AM Phase Shift Test 4 39 Pulse Modulation Test 4 41 Pulse On Off Ratio Test 4 42 Incidental AM Test 4 46 5 25 POWER SUPPLY ADJUSTMENTS REFERENCE Service Sheets 22 and 23 DESCRIPTION A digital voltmeter is used to check the power supply voltages They are then adjusted for the correct voltage This procedure should be performed before making any other adjustment EQUIPMENT Digital Voltmeter HP 3480D 3484A PROCEDURE l Set LINE switch to ON The fan should run and five LED s located on power supply boards 18 A
80. RESISTOR 4 64K RESISTOR 28 7K RESISTOR VAR TRMR RESISTOR 5 11K RESISTOR 1 OHM RESISTOR 619 OHM 1 RESISTOR 68 1 OHM 1 RESISTOR 422 OHM 1 RESISTOR 1 OHM JEDEC 2N3528 SI TO 39 PD 1W FT 15MHZ TO 5 075 THK SI TO 39 PD 700MW TO 5 075 THK SI CHIP PD 1W FT 15MHZ TO 5 075 THK SI CHIP PD 300MW SI TO 18 PD 360MW JEDEC 2N3528 1 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 1 125W F TUBULAR 1 5W F TUBULAR 1 125W F TUBULAR 1 125W F TUBULAR 1KOHM 10 C SIDE ADJ 1 125W F TUBULAR 5 2W PW TUBULAR 5W F TUBULAR 125W F TUBULAR 125W F TUBULAR 5 2W PW TUBULAR F TUBULAR RESISTOR 750 OHM 1 125W RESISTOR VAR TRMR 500 OHM RESISTOR 2 37K 1 125W F RESISTOR 511 OHM 1 125W RESISTOR 196 OHM 1 125W RESISTOR 750 OHM 1 125W RESISTOR 1 OHM 5 5W TUB RESISTOR 42 2 OHM 1 RESISTOR 68 1 OHM 1 RESISTOR 422 OHM 1 125W RESISTOR 1 OHM 5 2W PW T 2W PW T RESISTOR 1 OHM 5 2 05W F RESISTOR 2 61K 2 TERMINAL TERMINAL TERMINAL TERMINAL TERMINAL SLDR SLDR SLDR SLDR SLDR STUD STUD STUD STUD STUD SLDR SLDR SLDR SLDR SLDR STUD STUD STUD STUD STUD TERMINAL TERMINAL TERMINAL TERMINAL TERMINAL IC LIN REGULATOR IC LIN REGULATOR DIODE ZNR 10V 5 D0 7 PD DIODE ZNR 19 6V 5 DO 7 P DIODE ZENER 30 1V VZ DIODE ZNR 51 1V 5 DO 7 P DIODE ZNR 2 43V 5 DO 7 10 C SIDE ADJ TUBULAR F TUBULAR F TUBULAR F TUBULAR ULAR 125
81. Schematic Diagram 8 68 P O A8A2 Counter Lock Board Assembiy Component Locations 8 61 8 69 Counter Phase Lock Circuits Schematie Diagram 8 61 Foldback 8 62 A12 Rectifier Assembly Component Locations 8 72 A20 5 2V and 44 6V Regulator Assembly Component Locations Figure Page A22 20V and 20V Regulator Assembly Component Locations 8 63 8 74 Power Supply Circuits Schematic Diagram 8 63 8 75 A18 5 2V Regulator and Fan Driver Assembly Component Locations 8 65 8 76 5 2V Regulator and Fan Circuits Schematic Diagram 8 77 A17 Power Supply Mother Boss Assembly Component Locations 8 78 Power Supply Mother Board Schematic Diagram 8 79 A13 Modulation Metering Mother Board Assembly Component Locations 8 80 Modulation Metering Mother Board Schematic Diagram NP 8 69 8 81 Al and A19 Output Level Illustrated Parts Breakdown L amp 7i 8 82 RF Oscillator Transistor Preparation 8 72 8 83 JRF Oscillator Transistor Orientation 8 72 8 84 A3 RF Oscillator Illustrated Parts Breakdown 8 7 8 Counter Lock Parts Breakdown 2 8 87 Variable Frequency Modulation Oscillator Option 001 Illustrated Parts Breakdown 8 88 AI0 Divider Filter Assembly Illustrated Parts Breakdown L8 79 8 89 26 AM AGC and RF Amplifier Illustrated Parts Breakdown 8 81 8 9
82. TRASFORMER VARIABLE POWER CN 16 U TOOL KIT ELECTRONIC EQUIPMENT TK 100 G ADJUSTABLE STUB GR 874 D50L AMPLIFIER 20DB HP 8447A AMPLIFIER 20DB HP 8447B AMPLIFIER 40DB HP 465A AMPLIFIER 40 DB HP 08640 60506 ANTENNA LOOP HP 08640 60501 ATTENUATOR HP 355D OPT H36 ATTENUATOR HP 8491 OPT 003 ATTENUATOR HP 8491 OPT 010 ATTENUATOR HP 8491 OPT 020 CRYSTAL DETECTOR HP 8471A CRYSTAL DETECTOR HP 423A DIGITAL VOLTMETER HP 3408B 3484 OPT 042 043 DIRECTIONAL COUPLER HP 728D OPT 12 FM DISCRIMINATOR HP 5210A FEEDTHROUGH 6000HM HP 11095A FILTER NOTCH HP 10531A FILTER NOTCH HP 08640 60502 FILTER LOW PASS CIR Q TEL FLT 21B 4 3 50 3A 3B FILTER LOW PASS CIR Q TEL FLT 21B 1500K 3 50 3A 3B FILTER LOW PASS CIR Q TEL FLT 21B 15K 7 50 3A 3B FILTER LOW PASS CIR Q TEL FLT 21B 3K 5 50 3A 3B FUNCTION GENERATOR HP 3300A FM LINEARITY CIRCUIT HP 08640 60503 MIXER DOUBLE BALANCED HP 10514A NOISE PHASE LOCK CIRCUIT HP 08640 60504 PULSE GENERATOR HP 8002A 8013B POWER METER HP 432A 478A OPT H63 NATIONAL NATO STOCK NUMBER 6625 00 668 9418 6625 00 424 4370 6625 00 167 5267 6625 00 431 9339 6625 00 432 5055 6625 00 140 0156 6625 00 044 3228 6625 00 153 5990 6625 00 185 4802 6625 00 106 9622 6625 00 022 7894 5950 00 235 2086 5180 00 605 0079 TOOL NUMBER TOOL OR TEST EQUIPMENT REF CODE 42 43 44 45 46 47 48 SECTION III TOOL AND T
83. ac millivolt dc millivolt peak millivolt peak to peak millivolt rms milliwatt multiplex mylar microampere microfarad microhenry micromho microsecond microvolt microvolt ac microvolt dc microvolt peak Microvolt peak to peak microvolt rms microwatt Nanoampere no connection normally closed neon negative nanofarad nickel plate normally open negative positive negative 2 negative positive zero zero tempera ture coefficient not recommended for field replace ment not separately replaceable nanosecond nano watt order by descrip tion outside diameter oval head operational option oscillator peak used in parts list pulse amplitude modulation printed circuit pulse code modula tion pulse count modulation pulse duration modulation picofarad phosphor bronze Phillips positive intrinsic negative peak inverse PH BRZ PHL PIN oscillator phase modulation positive negative positive polystyrene porcelain Positive position s used in parts list Position Potentiometer Peak to peak peak to peak used in parts list pulse position modulation PREAMPL preamplifier PRF pulse repetition frequency pulse repetition picosecond point pulse time modulation pulse width modulation NOTE peak working voltage resistance capacitance rectifier reference regulated replaceable radio frequency radio freque
84. and thirteen CLEAR LOAD ee ee in DATA INPUTS D C i al e 2 DOWN 4 DATA OUTPUTS Qc 7 x p CARRY BORROW SEQUENCE 0 ILLUSTRATED AL COUNT UP COUNT DOWN NOTES A Clear overrides load data and count inputs B When counting up count down input is high when counting down count up input is high TA RESET Figure 8 14 Programmable Up Down Counter Model 8640B Option 004 Service OPERATIONAL AMPLIFIER A GAIN 1 OUTPUT OUTPUT INPUT IMPEDANCE VERY HIGH INPUT IMPEDANCE VERY HIGH OUTPUT IMPEDANCE VERY LOW OUTPUT IMPEDANCE VERY LOW C GAIN R1 R2 OUTPUT INPUT IMPEDANCE R2 DUTPUT IMPEDANCE VERY LOW IF A IS LARGE Vp ge RE IF V2 0 747 THEN IF V4 701 77 THEN Figure 8 15 Operational Amplifier 8 13 Service 8 14 COMPARATOR NON NVERTING OUTPUT INVERTING 4 DC REFERENCE INVERTING INPUT SIGNAL NON INVERTING INPUT Is il p cd Zen I Hm OUTPUT Figure 8 16 Comparator Model 8640B Option 004 4 SIGNAL INVERTING INPUT DC REFERENCE NON TNVERTING INPUT L oru Table 8 3 Assembly Information Index Assembly Output Level 1 dB Assy Meter Switch Detector Assy RF Oscillator Assy Meer Annunciator Drive Assy FM Ampl
85. is enabled The Stall Counier then begins counting up At the count of four a high is generated at the output Qc of the Stall Counter which clocks the count down input of the second counter U23 which subtracts ten from the count When the Stall Counter reaches the count of nine the clock to the main counter is enabled and the clock to the Stall Counter is disabled The count proceeds down until a zero count is reached and the sequence repeats In summary the counter counts down to zero then to 999 999 and then is preset to the stored count where it remains for four more elock pulses count pulse into the second counter then subtracts ten from the preset count Finally when a total of nine pulses has been counted by the Stall Counter the main counter starts counting down towards zero The stall of nine counts gives the main counters adequate time to preset The nine count delay plus the count to one below zero i e to 999 999 is compensated for by subtracting ten from the main counter The circuit implementation of the sequence is as follows When the count reaches 000 000 the borrow BRW output of U19 goes low The count proceeds to 999 999 at which time the borrow output goes high Normally the input to inverter U4A is held low by inductor L2 The high at the borrow output of U19 is ac coupled through capacitor C12 to the inverter and also the clear CLR input of the Stall Counter U28 The inputs are held high long enough to clea
86. on oscilloscope s display should be 5 4 to 6 7 divisions Level Accuracy 5 4 6 7 div 6 Repeat steps 1 through 5 for the frequency ranges shown below The rise and fall times and level accuracy should be as specified 4 75 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 41 PULSE MODULATION TEST Cont d Pulse Generator Signal Generator REN Pulse Pulse Rise Time Fall Time Level Accuracy Rate Width 1 2 MHz 2 4 MHz 4 8 MHz 8 16 MHz 16 32 MHz 7 Connect test generator to mixer and mixer to oscilloscope across 50 ohm load 8 Repeat steps 2 through 5 for the frequency ranges shown below At each frequency range set the puke generator as specified and set the reference signal generator for an output frequency 10 MHz below the output frequency of the test generator The reference generator s output should be at 7 dBm with no modulation Pulse Pulse Generator Signal Generator Frequency Rise Time Fall Time Level Accuracy Pulse RANGE Rate 32 64 MHz 64 128 MHz 128 256 MHz 256 512 MHz 4 76 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 42 PULSE ON OF RATIO TEST SPECIFICATION Pulse ON OFF ratio gt 40 dB DESCRIPTION The on off ratio of the pulse modulation circuits is measured with a spectrum analyzer See Table 4 1 Recommended Test Abridgements EQUIPMENT Spectrum Analyzer 141T 8552B 8554B PROCEDURE l Connect
87. spectrum analyzer Adjust the analyzer for full scale deflection of the signal in 10 dB log per vertical division with 100 Hz resolution bandwidth and 500 Hz to 2 kHz frequency span per division Set FM to INT and increase PEAK DEVIATION Vernier for a panel meter reading of 2 4 kHz note that the carrier decreases as peak deviation increases The carrier signal should be down greater than 18 dB from its original level which corresponds to a peak deviation accuracy of 10 NOTE To obtain a more accurate measurement adjust PEAK DE VIATION Vernier for a carrier null The panel meter should read 2 405 times the modulation rate measured in step 4b 10 The above steps may also be repeated for other carrier frequencies 0 475 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS Table 4 3 Record of Basic Functional Checks 1 of 2 Preliminary Checks Meter mechanical zero Clean air filter LINE ON OFF lamp Fan SCALE annunciators 0 5 0 10 0 3 REDUCE PEAK DEVIATION annunciator REDUCE FM VERNIER annunciator REDUCE PEAK POWER annunciator Counter and Frequency Checks Time base UNCAL annunciator Time base accuracy Decimal point OVERFLOW annunciator Frequency display LED s Phase lock achieved Phase lock range Phase lock range Phase lock broken Low frequency range High frequency range Band check and counter sensitivity 0 5 16 MHz m Band check and counter sensitivity 16 1024 MHz n Counte
88. switch knob is then set to the correct range This procedure should be performed whenever the 9 assembly or the AIO assembly has been removed or replaced EQUIPMENT Frequency Counter amp amp xs CHP 5327 PROCEDURE 1 Connect frequency counter high frequency input to RF OUT Set Signal Generator s controls as follows COUNTER MODE EXPAND Off LOCK Source NT 5 22 Model 8640B Option 004 Adjustments ADJUSTMENTS RANGE Fully CCW FREQUENCY TUNE 0 5 MHz OUTPUT LEVEL Switches 13 dBm OUTPUT LEVEL Vemier CAL RF ON OFF 2 Monitor output frequency with frequency counter Loosen shaft coupling between RANGE switch and divider filter cams Rotate cam side of shaft until frequency counter reading agrees with frequency indicated on generator s output frequency display i e to approximately 500 kHz tighten shaft coupling 3 Loosen RANGE switch knob position it so that it indicates that the range is 0 5 1 MHz and tighten it 4 Set RANGE switch to each of its other positions from both directions The frequency counter should display readings that agree approximately with generator s readout the correct frequency counter reading for the EXT DOUBLER 512 1024 MHz position is approximately 256 MHz 5 35 Vr POT ADJUSTMENT REFERENC
89. text for 40 appropriate 50 tolerances 60 70 80 4 2 divisions 4 2 divisions 2 8 divisions 201 2 mVrms Pulse Modulation Test 0 5 1 MHz Rise Time Fall Time Level Accuracy 1 2 MHz Rise Time Fall Time Level Accuracy 2 4MHz Rise Time Fall Time Level Accuracy 4 8 MHz Rise Time Fall Time Level Accuracy 8 16 MHz Rise Time Fall Time Level Accuracy 16 32 MHz Rise Time Fall Time Level Accuracy 32 64 MHz Rise Time Fall Time Level Accuracy 64 128 MHz Rise Time Fall Time Level Accuracy 128 256 MHz Rise Time Fall Time Level Accuracy 256 512 MHz Rise Time Fall Time Level Accuracy Model 8640B Option 004 Performance Tests Table 4 4 Performance Test Record 8 of 9 Test Description Pulse ON OFF Ratio Test Frequency Range 256 512 MHz 128 256 MHz 64 128 MHz 32 64 MHz 16 32 MHz 8 16 MHz 4 8 MHz 2 4 MHz 1 2 MHz 0 5 1 MHz FM Distortion Test Maximum Deviation 1 8 Maximum Deviation 2 287 kHz 2 287 kHz 2 287 kHz 2 4 MHz 1 2 MHz 0 5 1 MHz Incidental AM Test Maximum Deviation 1 8 Maximum Deviation FM Sensitivity and Accuracy Test Sensitivity Frequency Range 256 512 MHz 2 204 kHz 128 256 MHz 2 204 kHz 64 128 MHz 2 204 kHz 32 64 MHz 2 204 kHz 16 32 MHz 2 204 kHz 8 16 MHz 2 204 kHz 4 8 MHz 2 204 kHz 2 4 MHz 2 204 kHz 1 2 MHz 2 204 kHz 0 5 1 MHz 2 204 kHz Accuracy Frequency Range 256 512 MHz 2 287 kHz 128 256 MHz 2 287 kHz 64 128 MHz 2 287 kHz 32 64
90. wio A1A1J2 SiRF 14 DEMOD i AK 1331 A26A1R19 A3 RF OUT OUTPUT DEVIATION INPUT INPUT 26 1 1 DET OSCILLATOR Wil J5 COUNTER AND RANGE OUTPUT OUTPUT ASSY INPUT SWITCH ASSY A26A1TP2 A26A3J1 n 8 91 Rear Panel Vi i Figure 8 91 Rear Panel View Figure 8 92 Bottom Internal Views Option 001 Shown ARBRAR DA Pam 310 4 DA Pam 310 7 TB 43 0118 TM 38 750 TM 750 244 2 TM 11 6625 2780 14 amp P APPENDIX A REFERENCES Index of Technical Publications Technical Manuals Technical Bulletins Supply Manuals Types 7 8 and 9 Supply Bulletins and Lubrication Orders US Army Equipment Index of Modification Work Orders Field Instructions for Painting and preserving Electronics Command Equipment In cluding Camouflage Pattern Painting of Electrical Equipment Shelters The Army Maintenance Management System Procedures for Destruction of Electronics Materiel to Prevent Enemy Use Electronics command A 1 A 2 TM 11 6625 2780 14 amp P APPENDIX B COMPONENTS OF END ITEM LIST INTRODUCTION B 1 Scope This appendix lists integral components of and basic issue items for the HP 8640B to help you inventory items re quired for safe and efficient operation B 2 General This Components of End Item List is divided into the following sections a Section M Integral Components of the End Item Not applicable These items when assembled comprise the HP 86
91. 0 Model 8640B Option 004 General Information SECTION GENERAL 1 1 INTRODUCTION 1 2 This manual contains operating and service information for the Hewlett Packard Model 8640B Option 004 Signal Generator The Signal Generator with variable frequency modulation oscillator Option 001 is shown in Figure 1 Ilwith all of its externally supplied accessories 1 3 This section of the manual describes the instruments documented by this manual and covers instrument description options accessories speci fications and other basic information The other sections provide the following Installation information about initial inspection preparation for use and storage and shipment Operation information about panel features and provides operating checks instruc tions and maintenance information Section IV Performance Tests information re quired to check basic instrument functions and to verify that the instrument is performing as speci fied in Table 1 1 Section Adjustments information required to properly adjust and align the instrument Section V Replaceable Parts ordering informa tion for all replaceable parts and assemblies Section VII Manual Changes information to re vise this manual to document earlier configurations of the instrument and information suggesting in strument modifications Section Service information required to re pair the instrument 1 4 Dele
92. 0034 08640 20163 3150 0203 5001 0135 5060 0109 08640 00066 08640 00021 08640 4044 08640 00022 08640 00030 08640 00058 08640 00059 08640 20078 08640 20079 08640 20085 08640 20204 08640 40016 08640 40046 08640 40047 001 08640 40049 08640 40051 MOD FREQUENCY MODEL 8640B OPTION 004 REFERENCE DESIGNATION MP37 MP38 MP39 MP 40 MP41 MP 42 MP 43 MP44 MP45 46 47 48 49 50 51 52 MP53 MP54 MP55 MP56 MP57 MP58 MP59 MP 60 MP61 MP62 MP63 MP64 MP65 MP66 MP67 MP68 MP69 MP70 MP71 MP72 MP73 MP74 P1 P2 F3 Q1 Q2 Q3 Q4 Q5 R1 R1 R3 S1 S2 S3 T1 wi 172 w3 w4 5 w6 W7 ws W9 HP PART QTY NUMBER 08640 400551 08640 600361 5040 0388 1 5040 0389 1 5040 0390 1 3030 0007 0624 0267 0626 0002 1200 0043 1 3160 0217 5040 0170 3030 0007 5040 0447 1 08620 200161 08640 000141 08640 000151 0400 0005 1 0403 0026 8160 0238 1 8160 0239 1 08640 202281 08640 400521 08640 200571 08640 000771 08640 000781 5020 0343 1 1410 0758 1 08640 000721 08640 000731 08640 000741 7120 4244 1 08640 400671 3030 0007 1251 3294 1 1251 0198 5040 0327 1251 1249 1251 1313 1251 3054 2 1854 0063 4 1854 0063 1854 0250 1 1854 0063 1854 0063 2100 3325 1 0698 3449 3101 1395 1 3101 0070 3101 0163 9100 3350 1 8120 1378 1 8120 0660 1 8120 1890 1 08640 601271 8150 0447 2 8150 0496 2
93. 004 ADJUSTMENTS 5 30 OUTPUT LEVEL VERNIER AND METER ADJUSTMENT Cont d MODEL 8640B OPTION 004 99 90 0509 EQUIPMENT PROCEDURE NOTE 1 Check that the RF Detector Offset Adjustment 5 29 and the Meter Adjustrnents 5 28 are correct before performing this adjustment 2 After making meter adjustment which are accessible only from the bottom of the instrument check the adjustment with the instrument in its normal operating position 2048 10 dP STEP AMPLIFIER ATTENUATOR RF OUT AL D e N rers DOUBLE SHIELDED ster al CABLE POWER SENSOR Figure 5 2 Output Level Vernier and Meter Adjustment Test Setup Spectrum Analyzer HP 141T 8552B 8553B Power Meter HP 435A Power Sensor HP 8482A 20 dB Amplifier HP 8447A Double Shielded Cable 3 required HP 08708 6033 Adjustments l Connect equipment as shown Figure 5 2 after setting Signal Generator s controls as follows Meter Function LEVEL COUNTER MODE EXPAND Off LOCK Off Source INT AM OFF FM OFF RANGE 32 64 MHz FREQUENCY TUNE 50 MHz OUTPUT LEVEL Switches as specified OUTPUT LEVEL Vernier CAL RF ON OFF 5 15 Adjustments Model 8640B Option 004 10 11 12 5 16 ADJUSTMENTS Set OUTPUT LEVEL controls to 13 dBm Adjust LVL adjustment A26AARI for a 13 dBm reading on power meter Adjust MET adjustment A26A4R12 for a 13 dBm indication on generator s pan
94. 004 PERFORMANCE TESTS 4 29 OUTPUT IMPEDANCE TEST Broadband Cont d 2 Set spectrum analyzer for a frequency span of 50 550 MHz 300 kHz resolution bandwidth and 20 dB input attenuation Set tracking generator output level to O dBm 3 establish a reference level connect coaxial short to bridge output port Use the spectrum analyzer s vertical scale logrithmic level controls to set the reference level trace to the top of the analyzer display 4 Remove coaxial short and couple bridge output port to Signal Generators RF OUT connector difference in dB from the reference level established in step 3 to the level now visible on the display is the return loss of the generator s output port The return loss should be 29 5 dB from 50 to 512 MHz VSWR 2 0 1 9 5 dB 5 Set generators FREQUENCY TUNE control fully ccw and repeat steps 3 and 4 Return loss should be 29 5 dB from 50 to 512 MHz 9 5 dB 6 Set generator s OUTPUT LEVEL 10 dB switch two steps ccw to 0 dBm and repeat steps 3 and 4 Return loss should be gt 17 7 dB from 50 to 512 MHz VSWR 1 3 1 17 7 dB 7 Set generators FREQUENCY TUNE control fully cw and repeat steps 3 and 4 Return loss should be 217 7 dB from 50 to 512 MHz 17 7 dB 4 30 AUXILIARY OUTPUT TEST SPECIFICATION Auxiliary Output Rear panel BNC output is gt gt 5 dBm into 509 source impedance is approximately 500 2 DESCRIPTION The power level from the generator s rear
95. 0160 2055 150D104X9035A2 150D104X9035A2 150D104X9035A2 150D104X9035A2 150D104X9035A2 150D104X9035A2 150D104X9035A2 150D104X9035A2 150D104X9035A2 0160 3456 150D225X9020A2 150D225X9020A2 0160 3456 1901 0025 1901 0025 1901 0025 1901 0025 1901 0025 1901 0025 1901 0025 1901 0025 1901 0025 15 152 15 101 15 330 15 680 15 121 15 221 15 561 15 102 15 152 15 152 15 432 15 152 15 152 15 432 1854 0071 1853 0034 1853 0034 1853 0034 2N5179 C4 1 8 TO 51R1 F C4 1 8 TO 51R1 F C4 1 8 TO 51R1 F MF7C1 2 TO 10R0 F C4 1 8 TO 5111 F C3 1 8 TO 17R8 G C3 1 8 TO 287R G C3 1 8 TO 287R G C4 1 8 TO 51R1 F MF7C1 2 TO 10R0 F C4 1 8 TO 5111 F C3 1 8 TO 17R8 G C3 1 8 TO 287R G C3 1 8 TO 287R G C4 1 8 TO 51R1 F C4 1 8 TO 5111 F MF7C1 2 TO 10R0 F C3 1 8 TO 17R8 G C3 1 8 TO 287R G C3 1 8 TO 287R G C4 1 8 TO 75R0 F MF7C1 2 TO 10R0 F C4 1 8 TO 5111 F C3 1 8 TO 316R G C3 1 8 TO 196R G C3 1 8 TO 12R1 G C3 1 8 TO 422R G C3 1 8 TO 422R G C4 1 8 TO 133R F C4 1 8 TO 82R5 F MODEL 8640B OPTION 004 REFERENCE DESIGNATION A10A2R31 A10A2R32 A10A2R33 A10A2R34 A10A2R35 A10A2R36 A10A2R37 A10A2R38 A10A2R39 A10A2RA0 A1OA2R41 A10A2R42 A10A2R43 A10A2R44 A10A2R45 A10A2R46 A10A2R47 A10A2R48 A10A2R49 A10A2R50 A10A2R51 A10A2R52 A10A2R53 A10A2R54 A10A2R55 A10A2R56 A10A2R57 A10A2R58 A10A2R59 A10A2R60 A10A2R61 A10A2R62 A10A2T1 A10A2T2 A10A2T3 10 2 4 10 2 5 A10A2T6
96. 1 Output Leakage Test 0 5 to 400 MHz 400 to 600 MHz 600 to 1200 MHz Internal Modulation Oscillator Test 400 Hz Fixed Standard 392 408 Hz 1 0 Vrms Option 001 388 412 Hz 3 0 Vrms 1 kHz Fixed Standard 980 1020 Hz 1 0 Vrms Option 001 970 1030 Hz 3 0 Vrrns Model 8640B Option 004 Table 4 4 Performance Test Record 6 of 9 Test Description Internal Modulation Oscillator Distortion Test Option 001 Variable 20 Hz to 2 kHz 2 kHz to 600 kHz Fixed 400 Hz 1000 Hz AM 3 dB Bandwidth Test RANGE AM Bandwidth 8 16 MHz 50 0 50 kHz 909 0 35 kHz 4 8 MHz 50 0 30 kHz 9096 0 20 kHz 1 2 MHz 50 0 15 kHz 90 0 12 5 kHz AM Distortion Test AM sensitivity and Accuracy Test External sensitivity Accuracy Indicated Accuracy 90 10 50 30 0 10 30 0 3 20 10 Peak Incidental Phase Modulation Test 512 MHz 128 MHz Demodulated Output Accuracy Test AM Depth AC DC to AC 20 30 40 509 60 70 80 171 0 mVrms 165 6 mVrrns 128 8 mVrms 92 0 mVrrns 55 2 mVrms 54 6 mVrms 36 4 mVrms 18 2 mVrms Refer to Table in text for appropriate tolerances Performance Tests 189 0 mVrms 194 4 mVrms 151 2 mVrms 108 0 mVrms 64 8 mVrms 65 4 mVrms 43 6 mVrms 21 8 mVrms 4 99 Performance Tests Model 8640B Option 004 Table 4 4 Performance Test Record 7 of 9 Test Description Demodulated Output Accuracy Test AM Depth AC DC to DC 20 Refer to Table 80
97. 1 TABLE 6 3 DESCRIPTION REPLACEABLE PARTS VARIABLE FREQUENCY MODULATION OSC OPTION 001 ASSY CAPACITOR VAR INCLUDES C2 C3 NSR PART OF 11 1 NSR PART OF 11 1 CAPACTOR FXD 10PF 4 5 11HORIZ 500WVDC CER 0 CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR VAR TRMR CER 15PF 5 500WVDC CER 0 2000PF 1 300WVDC MICA 2000PF 1 300WVDC MICA 01UF 80 20 100WVDC CER 5 5 18PF CAPACITOR FXD 10UF 10 20VDC TA SOLID CAPACITOR FXD 100PF 5 300WVDC MICA CAPACITOR FXD 30PF 5 300WVDC MICA CAPACITOR FXD 6 8UF 10 35VDC TA CAPACITOR FXD 6 8UF 10 35VDC TA 3300 10 3300 10 6 8BUF 10 6 80 10 22UF 10 6VDC TA SOLID 6VDC TA SOLID 35VDC TA 35VDC TA 15VDC TA SOLID CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD 15 5 500WV9C CER 0 CAPACITOR FXD 25 500WVDC CER CAPACITOR FXD 100UF 10 10VDC TA CAPACITOR FXD 100UF 10 10VDC TA 2NS 2NS 2NS 2NS 2NS 50MA 50MA 50MA 50MA 50MA DIODE SWITCHING DIODE SWITCHING DIODE SWITCHING DIODE SWITCHING DIODE SWITCHING 30V 30V 30V 30V 30V DIODE SWITCHING 2NS 30V 50MA DIODE SWITCHING DIODE SWITCHING DIODE SWITCHING DIODE SWITCHING 2NS 30V 50MA 2NS 30V 50MA 2NS 30V 50MA 2ND 30V 50MA TERMINAL STUD DBL TURRET PRESS MTG 221 TERMINAL BUSHING TEFLON MOUNTS IN TERMINAL STUD DBL TURRET PRESS MTG 221 TERMINAL BUSHING TEFLON
98. 1 125W F TUBULAR ATR2 0698 3450 8 RESISTOR 42 2K 1 125W F TUBULAR ATR3 0698 3153 3 RESISTOR 3 83K 1 125W F TUBULAR ATR4 0757 0199 RESISTOR 21 5K 1 125W F TUBULAR 7 5 0757 0440 RESISTOR 7 5K 1 125W F TUBULAR ATR6 0698 3243 1 RESISTOR 178K 1 125W F TUBULAR ATR7 0698 3454 2 RESISTOR 215K 1 125W F TUBULAR ATR8 0757 0289 3 RESISTOR 13 3K 1 125W F TUBULAR ATR9 0698 3161 2 RESISTOR 38 3K 1 125W F TUBULAR 10 0698 3154 6 RESISTOR 4 22K 1 125W TUBULAR 7 11 0757 0288 RESISTOR 9 09K 1 125W TUBULAR 7 12 2100 3109 RESISTOR VAR TRMR 2 10 SIDE ADJ ATR13 0757 0279 RESISTOR 3 16K 1 125W F TUBULAR 7 14 0698 3260 RESISTOR 464K 1 125W F TUBULAR 15 0757 0458 4 RESISTOR 51 1 1 125W TUUBLAR ATR16 0757 0443 RESISTOR 11K 1 125W F TUBULAR 7 17 0698 3155 5 RESISTOR 4 64K 1 125W TUBULAR 18 0757 0123 2 RESISTOR 34 8 1 125W TUBULAR ATR19 2100 3103 3 RESISTOR VAR TRMR 10KOHM 10 C SIDE ADJ 20 0698 3152 1 RESISTOR 3 485 1 125W F TUBULAR 7821 0757 1094 4 RESISTOR 1 47 1 125W F TUBULAR 7 22 0757 0278 RESISTOR 1 78 1 125W TUBULAR 7 23 0757 0279 RESISTOR 3 16 1 125 TUBULAR 7 24 0757 0290 RESISTOR 6 19 1 125W TUBULAR 7 25 0757 0443 RESISTOR 11K 1 125W TUBULAR ATR26 0698 3157 RESISTOR 19 6K 1 125W F TUBULAR ATR27 0698 3160 RESISTOR 31 6K 1 125W F TUUBLAR 28 0757 0461 1 RESISTOR 68 15 1 125W TUBULAR ATR29 0757 0401 RESISTOR
99. 100WVDC CER 28480 0160 2055 10 1 4 0160 2055 CAPACITOR FXD 01UF 80 20 100WVDC CER 28480 0160 2055 10 1 5 0160 2055 CAPACITOR FXD 010 80 20 100WVDC CER 28480 0160 2055 A10A1C6 0160 2055 CAPACITOR FXD 01UF 80 20 100WVDC CER 28480 0160 2055 10 1 7 0160 2055 CAPACITOR FXD 010 80 20 100WVDC CER 28480 0160 2055 A10A1C8 0160 2055 CAPACITOR FXD 01UF 80 20 100WVDC CER 28480 0160 2055 A10A1C9 0140 0219 2 CAPACITOR FXD 180PF 2 200WVDC MICA 72136 DM15F181G0300WVICR A10A1C10 0140 0226 2 CAPACITOR FXD 320PF 1 300WVDC MICA 72136 DM15F321F0300WV1C MODEL 8640B OPTION 004 REFERENCE HP PART DESIGNATION NUMBER 10 1 11 0140 0226 A10A1C12 0140 0220 A10A1C13 0140 0195 10 1 14 0140 0220 10 1 15 0140 0220 10 1 16 0140 0195 10 1 17 0160 3156 A10A1C18 0160 3940 A10A1C19 0160 2587 A10A1C20 0160 4217 A10A1C21 0160 2276 A10A1C22 0140 0172 A10A1C23 0160 2585 A10A1C24 0160 2537 A10A1C25 0160 0341 A10A1C26 0160 0341 A10A1C27 0140 0200 A10A1C28 0140 0199 A10A1C29 0160 0939 A10A1C30 0160 0939 A10A1C31 0140 0199 A10A1C32 0160 2537 A10A1C33 0160 3092 A10A1C34 0160 2585 A10A1C35 0160 3937 A10A1C36 0160 3939 A10A1C37 0160 3938 A10A1C38 0160 2387 A10A1C39 0160 0335 A10A1C40 0160 2206 10 1 41 0160 2206 10 1 42 0160 2204 10 1 43 0140 0205 10 1 44 0160 0839 10 1 45 0160 0839 10 1 46 0140 0205 10 1 47 0140 0219 10 1 48 0160 0342 10 1 49 0160 2387 A10A1C50 0160 3835
100. 104 2 58 to 51 1K CHANGE B Page 6 11 Table 6 3 Change A8A4R1 to 2100 3299 RESISTOR VAR 5K 20 MC SPST SW Page 6 22 Table 6 3 Delete A10A2C54 6 29 Table 6 3 Change 1802 to 1854 0039 TRANSISTOR NPN 2N3053 81 PD IW Table 6 3 Change 20 Q2 to 1854 0039 TRANSISTOR NPN 2N3053 S1 PD IW 6 32 Table 6 3 Change 2202 and Q3 to 1854 0039 TRANSISTOR NPN 2N3053 51 PD IW Service Sheet 11 schematic Delete A20A2C54 NOTE paragraph 7 1 recommended instrument modification 7 4 Model 8640B Option 004 Manual Changes MANUAL CHANGES NOTE Sed paragraph 7 13 for recommended instrument modification Service Sheet 23 schematic Change A18Q2 to 1854 0039 NOTE See puragraph 7 13 for recommended instrument modification CHANGE C Page 6 18 T able 6 3 Add A9R2 0698 4014 RESISTOR FXD 787 OHM 1 0 125W F Pages 6 25 and 6 26 Table 6 3 Change 1101 to 1853 0020 TRANSISTOR PNP 51 PD 300 MW FT 150 MHz Change A11R2 and R6 to 0698 3452 RESISTOR FXD 196K 196 0 125W F TUBULAR Page 6 28 Table 6 3 Change A12 08640 60003 Add A12Q1 1884 0012 THYRISTOR SCR J EDEC 2N3528 Add A12R1 0757 0401 RESISTOR FXD 100 OHM 196 0 125W F TUBULAR Add A12R2 0698 3447 RESISTOR FXD 422 OHM 196 0 125W F TUBULAR Add A12VR1 1902 3393 DIODE ZENER 75 VZ 0 4W MAX PD Delete A13R6 Page 6 33 Table 6 3 Add A26A2CR6 1901 0040 DIODE SWITCHING S1 30V MAX VRM 50 MA
101. 1100 MHz with 7 frequency over range Conver sion low in the doubler is typically lt 13 dB 1 74 Mixer The HP Model 10514A Double Bal ancedi Mixer can be used at the generator s output as a nanosecond pulse modulator or as a balanced mixer 1 75 Protective Cover The HP 5060 8767 Con trol Panel Cover protects the panel from dust and impact damage 1 76 SERVICE AND USER AIDS 1 77 Video Tapes Video tapes covering instru ment use application and service are available Contact the nearest Hewlett Packard Sales and Service Office for a list of presently available tapes 1 78 Application Notes Informative notes con cerning the use of signal generators are also available from the nearest Hewlett Packard Sales and Service Office 1 79 Service Notes Hewlett Packard makes de sign improvements to its current line of instru ment on a continuing basis Many of these improvements can be incorporated in earlier pro duced instruments Modification and general ser General Information vice information is passed on in the form of Service Notes To obtain the Service Notes contact the nearest Hewlett Packard Sales and Service Office 1 80 Deleted 1 81 Deleted 1 82 TEST EQUIPMENT REQUIRED 1 83 and 1 3 list the test equipment and accessories required to check adjust and repair the Model 8640B Option 004 Table 4 2 is separate list of relatively inexpensive commonly available test equipment for the Basic Fu
102. 15 Hz Output Level Accuracy Test Abbreviated Output Level 10 dB Meter Reading 4 96 Fully CW Fully CW Fully CW Fully CW Fully CW Fully CW 1 step cew step 1 step 1 step 1 step ccw 1 step 1 step 1 step ccw 1 step 1 step 1 step ccw step 1 step 2 steps ccw 3 steps ccw 4 steps ccw 5 steps ccw 6 steps ccw 7 steps ccw 8 steps ccw 9 steps ccw 10 steps ccw 15 dBm 14 dBm 13 dBm 12 dBm 11 dBm 10 dBm 10 dBm 9 dBm 8 dBm 7 dBm 6 dBm 5 dBm 4 dBm 3 dBm 2 dBm 1 dBm 0 dBm dBm 2 dBm 0 dBm 11 dBm 21 dBm 31 dBm 41 dBm 51 dBm 61 dBm 71 dBm 81 dBrn 15 mVrms 13 5 dBm 12 5 dBm 11 5 dBm 10 5 dBm 9 5 dBm 8 5 dBm 8 5 dBm 7 5 dBm 6 5 dBm 5 5 dBm 4 5 dBm 3 5 dBm 2 5 dBm 1 5 dBm 0 5 dBm 0 5 dBm 1 5dBm 2 5 dBm 3 55 dBm 1 5dBm 12 5 dBm 2dB 2dB 2dB 2 5dB 2 5dB 2 5dB 2 5 dB 16 5 dBm 15 5 dBm 14 5 dBm 13 5 dBm 12 5 dBm 11 5 dBm 11 5 dBm 10 5 dBm 9 5 dBm 8 5 dBm 7 5 dBm 6 5 dBm 5 5 dBm 4 5 dBm 3 5 dBm 2 5 dBm 1 5 dBm 0 5 dBm 0 5 dBm 1 5 dBm 9 5 dBm 2dB 2 dB 2 dB 2 5 dB 2 5 dB 2 5 dB 2 5 dB Model 8640B option 004 Performance Tests Table 4 4 Performance Test Record 4 of 9 Test Description Output Level Accuracy Test Cont d Abbreviated Outpu
103. 1514 1826 0092 1826 0026 1 1820 0328 1820 0471 1 1902 0025 1902 3203 08640 600681 1251 3231 1 08640 600671 1251 1886 2 1251 1886 1251 2571 08640 600691 0180 0116 0160 2055 0180 0116 0160 2055 0180 0116 0160 2055 4040 0749 4040 0754 0698 3334 2 0698 3334 2100 2633 0757 0442 0757 0280 2100 3103 0757 0440 2100 3103 0698 3450 2100 3109 TABLE 6 3 DESCRIPTION REPLACEABLE PARTS RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 422 OHM 1 125W F TUBULAR 3 16K 1 125W F TUBULAR 5 11K 1 125W F TUBULAR 100K 1 125W F TUBULAR 100K 1 125W F TUBULAR RESISTOR 1 96K 1 NOT ASSIGNED RESISTOR 3 83K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 10 OHM 1 125W F TUBULAR 125W F TUBULAR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 100K 1 100K 1 1 96K 1 42 2K 1 10K 1 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 4 22K 1 125W F 100 OHM 1 125W 13 3K 1 125W F TUBULAR 2 37K 1 125W F TUBULAR 133K 1 125W F TUBULAR TUBULAR F TUBULAR NOT ASSIGNED RESISTOR 1K 1 125W F TUBULAR RESISTOR 1 78K 1 125W F TUBULAR RESISTOR 825 OHM 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR RESISTOR 825 OHM 1 125W F TUBULAR TERMINAL SLDR STUD TERMINAL SLD STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL S
104. 16 11 17 11 18 11 19 A11C20 11 21 A11C22 A11C23 A11CR1 11 2 Al1CR3 11 4 11 5 A11CR6 A11CR7 A11CR8 11 9 A11CR10 1 11 2 11 11 4 11 5 11 6 11 7 11 8 11 9 11 10 11 11 11 12 11 13 11 14 11 15 11 16 11 17 1101 1102 1103 1103 1104 1105 1106 1106 1107 1108 1109 11010 11011 11012 11 1 Al1R2 Al1R3 11 4 A11R5 HP PART NUMBER QTY 08640 600191 0121 0477 1 0160 2257 1 0160 2261 2 0140 0213 2 0140 0213 0160 2055 1 0121 0036 m 0180 0374 0160 2204 0160 2199 0180 0116 0180 0116 0180 1714 2 0180 1714 0180 0116 0180 0116 0180 0228 1 0160 2261 0160 2236 1 0180 2207 2 0180 2207 1901 0040 10 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 0340 0037 2 0340 0039 2 0340 0037 0340 0039 1430 0764 1 08640 000061 08640 20090 4 08640 00008 1 08640 20062 1 2200 0103 1 0570 0111 2190 0004 2260 0009 0403 0026 4040 0749 1480 0073 08640 20090 08640 20090 08640 20090 08640 00081 1 1853 0050 1854 0071 1853 0276 1200 0173 1854 0351 1854 0003 2 1854 0003 1200 0173 1854 0351 1853 0276 1854 0071 1853 0020 1 1855 0062 1 1854 0071 0698 8294 2 0698 3453 2 0698 4508 1 0698 8294 0698 3451
105. 2 A26A1CR3 A26A1CR4 A26A1CR5 A26A1CR6 26 111 A26A1L2 A26A101 A26A102 A26A103 A26A104 A26A105 26 106 26 107 A26A108 26 109 A26A1R1 A26A1R2 A26A1R3 A26A1R4 A26A1R5 A26A1R6 A26A1R7 A26A1R8 A26A1R9 A26A1R10 A26A1R11 A26A1R12 A26A1R13 A26A1R14 A26A1R15 A26A1R16 A26A1R17 A26A1R18 A26A1R19 A26A1R20 HP PART NUMBER QTY 2360 0201 1 2950 0078 2190 0124 2190 0012 2190 0014 2190 0018 3050 0228 1 2950 0035 1 2190 0068 1 0361 1071 0403 0158 0757 0159 1 08640 670061 08640 670031 8120 1889 1 8120 1887 1 8120 1905 1 8120 1892 1 08640 600741 0160 3094 0160 3094 0160 3094 0140 0198 1 0160 2204 0180 0197 1901 0040 1901 0022 8 1901 0040 1901 0040 1901 0040 1901 0539 4 9100 1620 9140 0180 1 1853 0007 3 1855 0049 1 1855 0020 1 1853 0007 1854 0071 1854 0071 1854 0071 1854 0071 1854 0071 0698 3447 0698 3446 0757 0420 0757 0317 0757 0420 0757 0280 0757 0441 0698 3443 1 0757 0199 0757 0199 0757 0458 0683 3355 1 0698 3450 0698 3450 0683 1055 2 0698 3438 0698 3132 0757 0438 2100 2061 1 0757 0442 TABLE 6 3 DESCRIPTION REPLACEABLE PARTS SCREW MACH 6 32 PAN HD POZI REC SST 300 NUT HEX DBL CHAM 10 32 THD 067 THK 25 WASHER LK INTL T NC 10 195 IN ID 311 WASHER LK EXT T NO 10 195 IN ID 406 WASHER LK INTL T NO 2 089 IN ID 185 WASHER LK HLCL NO 6 141 IN ID 269 IN WASHER FL MTLC 156 IN ID 312 IN OD NUT HEX
106. 221 70 1343 1250 0257 CONNECTOR RF SMB 28480 1250 0257 A13J4 1250 0257 CONNECTOR RF SMB M PC 28480 1250 0257 A13J5 1251 3055 CONNECTOR STRIP 8 MALE CONTACT 74868 221 70 A13MP1 0403 0026 GLIDE NYLON 28480 0403 0026 1 2 7120 1232 1 BLK LBL NO TEXT 0052B 3659 SCOTCH CAL A13MP3 08640 20211 GUIDE CONNECTOR 28480 08640 20211 13 4 08640 400631 GUIDE SLIDE SWITCH 28480 08640 40063 13 1 NOT ASSIGNED A13R2 0757 0460 RESISTOR 61 9K 1 125W F TUBULAR 24546 C4 1 8 TO 6192 F A13R3 2100 1986 1 RESISTOR VAR TRMR 1KOHM 10 C 30983 ET50W102 A13R4 0757 0443 RESISTOR 11K 1 125W F TUBULAR 24546 C4 1 8 TO 1102 F A13R5 0757 0460 RESISTOR 61 9K 1 125W F TUBULAR 24546 C4 1 8 TO 6192 F A13R6 0698 4014 1 RESISTOR 787 OHM 1 125W F TUBULAR 16299 C4 1 8 TO 787R F 1351 08640 601521 SWITCH SLIDE 4R 28480 08640 60152 5020 3440 2 SPRING DETENT 5020 3440 08640 40063 4 GUIDE SLIDE SWITCH 08640 40063 1352 08640 601531 SWITCH PC SLIDE SR 28480 08640 60153 5020 3440 SPRING DETENT 5020 3440 08640 40063 GUIDE SLIDE SWITCH 08640 40063 13 11 1251 2571 9 CONNECTOR EDGE 15 DIP SOLDER 26742 91 6915 0702 00 A13XA15 1251 2035 CONNECTOR PC EDGE 15 CONT DIP SOLDER 71785 252 15 30 300 A13XA2 1251 2571 CONNECTOR PC EDGE 15 CONT DIP SOLDER 26742 91 6915 0702 00 A13XA3A4 1251 0472 CONNECTOR EDGE 6 CONT DIP SOLDER 71785 252 06 30 300 13 4 1251 2571 CONNECTOR EDGE 15 DIP SOLDE
107. 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 26365 NATIONAL STOCK NUMBER 5310 00 460 3057 5950 00 438 4376 5950 00 431 3195 5950 00 431 3196 5950 00 469 3077 5950 00 431 3197 5950 00 431 3203 5950 00 431 3210 5950 00 584 0107 5950 00 578 1933 5950 00 805 5186 5950 00 455 7744 5950 00 657 8167 5950 00 984 3433 5950 00 971 1645 5950 00 837 6029 5950 00 199 7652 5950 00 101 2507 5970 00 869 8798 NUMBER FSCM NATIONAL STOCK NUMBER Model 8640B option 004 Manual Changes SECTION VII MANUAL CHANGES 7 1 INTRODUCTION 7 2 This section contains manual change instruc tions for backdating this manual for HP Model 8640B Option 004 Signal Generators that have serial number prefixes that are lower than 1435A This section also contains instrument modification suggestions and procedures that are recommended to improve the performance and reliability of your generators 7 3 MANUAL CHANGES 7 4 To adapt this manual to your instrument refer to Table 7 1 and make all of the manual changes listed opposite your instrument s serial number or prefix The manual changes are listed in serial number sequence and should be made in the sequence listed For example Change A should be made after Change B Change B should be made after Change C etc Table 72 hs a summary of changes by component
108. 333 MHz If AC DC switch A26A8S1 is set to AC repeat steps 10 to 13 for 333 MHz If AC DC switch A26A8S1 is set to DC repeat steps 10 to 12 and step 14 for 333 MHz 4 39 AM PHASE SHIFT TEST SPECIFICATION Phase shift from Audio Input to Demodulated Output 108 to 118 MHz AM source selector set to DC 30 Hz lt 0 01 30 HZ to 10 kHz lt 3 9 kHz to 11 kHz lt 1 difference from 9 to 11 kHz DESCRIPTION The X and Y axes of an oscilloscope are driven respectively by the audio input and demodulated output The phase difference of the two signals is noted from the resulting Lissajous pattern The measurement for 30 Hz is made indirectly by measuring the phase shift at 10 000 Hz and 1000 Hz If the phase shift at 1000 Hz is 1 10 the phase shift at 10 000 Hz the phase can be assumed to vary linearly with frequency i e a single pole response and the phase shift at 30 Hz equals 0 03 the phase shift at 1000 Hz Sec Table Recommended Test Abridgements NOTE For a single pole frequency response phase tan f fo where fo is the cutoff frequency Since f fo for our application f fo TEST OSCILLATOR MODEL 86408 OPTION 004 OSCILLOSCOPE 0000 O9 oO o 0000 DEMOD OUTPUT ST OUTPUT INPUT TEE Figure 4 23 AM Phase Shift Test Setup EQUIPMENT Oscilloscope HP 180A 1801A 1820C Test Osci
109. 35VDC TA 2 2UF 10 20VDC TA 1000PF 10 1000WVDC CER 22UF 10 15VDC TA SOLID 22UF 10 15VDC TA SOLID 470PF 10 1000WVDC CER 28480 1854 0404 28480 1854 0404 24546 C3 1 8 TO 1001 G 24546 C3 1 8 TO 3161 G 24546 C3 I 8 TO 3161 G 24546 C3 I 8 TO 100R G 24546 C4 1 8 TO 51R1 F 24546 C4 1 8 TO 511R F 24546 C4 1 8 TO 511R F 24546 C4 1 8 TO 1471 F 24546 C4 1 8 TO 511R F 24546 C3 1 8 TO 237R G 24546 C3 1 8 TO 23R7 G 24546 C3 1 8 TO 237R G 28480 1820 0736 28480 1820 1003 04713 MC1010P 04713 MC1013P 28480 5086 7089 28480 08640 60027 28480 08640 60087 28480 0160 3456 28480 0160 3094 28480 0160 3094 56289 30D206G050CC2 56289 150D224X9035A2 56289 150D225X9020A2 28480 0160 3456 56289 150D226X9015B2 56289 150D226X9015B2 28480 0160 3455 MODEL 8640B OPTION 004 REFERENCE DESIGNATION A8A2C11 A8A2C12 A8A2C13 A8A2C14 A8A2C15 A8A2C16 A8A2C17 A8A2C18 A8A2C19 A8A2C20 A8A2C21 A8A2C22 A8A2C23 A8A2C24 A8A2C25 A8A2C26 A8A2C27 A8A2C28 A8A2C29 A8A2C30 A8A2C31 A8A2CR1 A8A2CR2 A8A2L1 A8A2L2 A8A2Q1 A8A2Q2 A8A2Q3 A8A204 A8A205 8 206 A8A2Q7 A8A208 8 209 8 2010 8 2011 8 2012 8 2013 8 2014 8 2015 8 2016 8 2017 8 2018 A8A2R1 A8A2R2 A8A2R3 A8A2R4 A8A2R5 A8A2R6 A8A2R7 A8A2R8 A8A2R9 A8A2R10 A8A2R11 A8A2R12 A8A2R13 A8A2R14 A8A2R15 A8A2R16 A8A2R17 A8A2R18 A8A2R19 A8A2R20 A8A2R21 A8A2R22 A8A2R23 A8A2R24 A8A2R25 A8A2R26 A8A
110. 4 and 4 8 MHz ranges called LO BAND 2 In a similar manner resistor R55 is switched in parallel with C18 and R57 to attenuate the signal in the pulse modulation mode of operation Transistor Q5 is a current source Transistor Q6 is a constant current sink The difference between the collector currents of Q5 and Q6 is the modulator drive current In the pulse modulation mode of operation Q5 is switched on and off at the pulse repetition rate by transistor switch Q7 which is driven by the pulse Schmitt Trigger output of A26A2 Service Sheet 13 When Q7 is on Q5 and the modulator are off i e when either the MOD PULSE line is low or when the RF OFF line is low Hot carrier diodes and CRI4 prevent saturation of Q7 and Q6 for rapid switching Capacitor C15 is switched in across the modulator drive line by gates U3C and UAE to lower the rise and fall time of the modulator in LO BAND 1 ranges to reduce RF ringing in the filters following the modulator Similarly capacitor C16 is switched in for LO BAND 2 ranges Pulse Overload Detector In the pulse modulation mode the peak detector in A26UI Service Sheet 13 samples the RF output only when an input pulse is present when no pulse is present the detector output is stored on a capacitor If the OUTPUT LEVEL vernier is reduced while in the pulse mode the error voltage of the summing amplifier becomes very large and the modulator is turned off The detector storage capacitor then di
111. 5 300WVDC MICA CAPACITOR FXC 6 80 10 35VDC CAPACITOR FXD 1500 10 6VDC TA SOLID CAPACITOR FXD 10 75 10 150VDC AL 2 2UF 10 20VDC TA CAPACITOR FXD 6 BUF 10 35VDC CAPACITOR FXD 50 5 10 150VDC AL CAPACITOR FXD 430P 5 300WVDC MICA CAPACITOR FXD NOT ASSIGNED NOT ASSIGNED NOT ASSIGNED NOT ASSIGNED DIODE GEN PRP 100V 200MA MODEL 8640B OPTION 004 MFR CODE 16299 24546 24546 28480 28480 28480 28480 56289 28480 28480 28480 28480 28480 28480 00000 28480 28480 28480 24546 24546 24546 16299 24546 24546 24546 19701 19701 19701 24546 24546 24546 24546 24546 19701 19701 19701 19701 01121 01121 28480 28480 28480 28480 28480 28480 28480 27014 27014 01295 01295 04713 04713 28480 28480 28480 56289 56289 56289 56289 56289 56289 28480 28480 MFR PART NUMBER C4 1 8 TO 178R F C4 1 8 TO 511R F C4 1 8 TO 511R F 0360 1514 0360 1514 08640 60056 0160 2199 150D226X9015B2 0160 2055 0160 2055 0160 2199 1901 0040 1901 0025 4040 0750 OBD 1854 0071 1854 0019 1854 0019 C4 1 8 TO 1002 F C4 1 8 TO 1002 F C4 1 8 TO 2152 F C4 1 8 TO 316R F C4 1 8 TO 6192 F C4 1 8 TO 1001 F C4 1 8 TO 1002 F MF4C1 8 C 1002 C ET50X203 MF4C1 8 C 1002 C C4 1 8 TO 3161 F C4 1 8 TO 1001 F C4 1 8 TO 1001 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F MF4C1 8 T2 79951 C MF52C1 4 T2 7401 C ET50X202 MF4C1 8 T0 9091 F CB1065
112. 5022 receiver FM de coupled at least 40 kHz deviation for 1V input HP 141T 8552B 8556A Range 20 200 kHz Amplitude Calibration Display Accuracy 0 25 dB dB but not more than 1 5 dB over 70 dB dynamic range Flatness 0 2 dB Vertical Reference Scale 10 dB division log 2 dB division or less log and linear display calibration Average Noise Level lt 120 dBm 500 with 1 kHz IF bandwidth Spurious Responses gt 60 dB down for nomi nal specified inputs Tracking Generator Flatness 0 25 dB Level gt 3 Vrms into 6002 HP 141T 8552B 8554B Range 0 5 1200 MHz Amplitude Calibration Display Accuracy 0 25 dB dB but not more than 1 5 dB over 70 dB dynamic range Flatness 1 dB IF Gain Step Accuracy 0 2 dB Vertical Reference Scale 10 dB division log 2 dB division or less log and linear display calibration Average Noise Level lt 102 dBm with 10 kHz IF bandwidth Spurious Responses gt 60 dB down for inputs of 40 dBm or less Span Width 0 1 GHz Compatible with Tracking Generator 1 17 General Information Model 8640B Option 004 Table 1 2 iRecommended Test Equipment 5 of 6 Instrument Type Critical Specifications Suggested Model Spectrum Analyzer Range 0 45 550 MHz HP 141T IF Bandwidths down to 10 Hz 8552B 8553B All other specifications are the same as the HP 1
113. 512 MHz and FREQUENCY TUNE to 550 MHz with counter at RF OUT COMPARATOR A8A1 Set COUNTER Frequency at U3B pin 6 MODE to EXT 0 550 8 58 MHz ECL to TTL Initial conditions and TRANSLATOR settings except set A8A3 COUNTER MODE to INT 8 54 Normal Indication Frequency at COUNTER INPUT the same as U3B pin 6 Frequency at COUNTER INPUT 64 times fre quency at U3B pin 6 Frequency at U3B pin 6 amp 8 58 MHz 0 5V square wave at Q2 C at 8 MHz If Indication is Abnormal Check 2 05 QI U3D and associated circuitry Check K2 U5 UI U2 U3B U4 Q2 and asso ciated circuitry Check 05 and associated circuitry Check CR2 CR3 K2 and associated circuitry Check Q2 and associated circuitry 904965 Upton Figure 8 61 P O A8A3 Time Base Assembly Component Locations Service SCALER ASSEMBLY 08640 60168 P O Jl ECL TO TTL TRANSLATOR PIO ABAS RI SER ASSY 1 LJ COUNTER 1 45 2 COUNTILGCK TO TIME BASE INPUT Dod us 01 0860 80028 __ a imum COMPARATOR Samana 8 MHz R21 n 16 e 20 1000 52 INTERNAL INPUT ia aa i 1 BASE ASSY 08640 60026 1854 0019 Ex a1 R7 D 1 lt INTEXT 0 0 uF 511 lr E as aie 7 T 041 pF b erm TF
114. 6 3 REPLACEABLE PARTS DESCRIPTION RESISTOR 10K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 2 61K 1 125W F TUBULAR RESISTOR 2 61K 1 125W F TUBULAR RESISTOR 82 5 OHM 1 125W F TUBULAR RESISTOR 82 5 OHM 1 125W F TUBULAR RESISTOR 21 5 OHM 1 5W F TUBULAR RESISTOR 100 OHM 1 5W F TUBULAR RESISTOR 9 1 OHM 5 25W CC TUBULAR RESISTOR 9 1 OHM 5 25W CC TUBULAR RESISTOR 464K 1 125W F TUBULAR TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STD TERMINAL SLDR STUD IC LIN LM302 FOLLOWER ANNUNCIATOR ASSY LAMP INCAND T 1 BULB 5V 0 06A LAMP INCAND T 1 BULB 5V 0 06A LAMP INCAND T 1 BULB 5V 0 06A LAMP INCAND T 1 BULB 5V 0 06A LAMP INCAND T 1 BULB 5V 0 06A LAMP INCAND T 1 BULB 5V 0 06A CONNECTOR STRIP 9 OPEN POSIITON PLZG KEY PRINTED CIRCUIT CONN CONTACT CONN U W MICRO SER FEM RESISTOR 10 OHM 1 125W F TUBULAR FM SHAPING BOARD ASSY CAPACITOR FXD 220 10 35VDC CAPACITOR FXD 220 10 35VDC CAPACITOR FXD 680 10 35VDC CAPACITOR FXD 3 30 10 50VDC CAPACITOR FXD 500 75 10 50VDC AL CAPACITOR FXD 1500 10 6VDC TA SOLID CAPACITOR FXD 22UF 10 80WVDC POLYE CAPACITOR FXD 2 20 10 35VDC CAPACITOR FXO 100PF 5 300WVDC MICA CAPACITOR FXD 500 75 10 50VDC AL CAPACITOR FXD 1500 10 LVDC TA SOLID CAPACITOR FXD 100PF 5 300WVDC MICA CAPACITOR FXD 600 10 6VDC TA SOLID
115. 7 c Calculate the average of the two values of offset voltage and use this Voff in step 12 the difference between the two values of offset voltage should be lt 2 mVdc Voff Set the Signal Generator RANGE to 128 256 MHz and FREQUENCY TUNE to 190 2 MHz Set calibrated step attenuator to 10 dB Set the spectrum analyzer to display the 190 MHz signal with zero frequency span then peak the trace Set AM to DC Set the test oscillator frequency to 120 Hz and adjust the level to give approximately 50 AM as read on the Signal Generator panel meter Adjust the spectrum analyzer s vertical sensitivity to give a digital voltmeter reading of 282 8 mV Voff e g if Voff from step 8 is 50 0 mV adjust the spectrum analyzer to give a digital voltmeter reading of 232 8 mVdc Set AC DC switch A26A8S1 to AC Set the digital voltmeter to read mVac and adjust the test oscillator level to give a reading of 100 mVrms Switch the digital voltmeter to read the DEMOD OUTPUT voltage and adjust AC GAIN 26 8 8 to give a reading of 2500 5 mVrms NOTE AM Distortion must be lt 1 Set AC DC switch A26A8S1 to DC Repeat step 13 except adjust DC GAIN 26 8 10 to give reading of 500 00 0 05 mVrrns Set the digital voltmeter to read dc volts and adjust DC OFFSET 26 8 15 to give 1414 1 mVdc Perform DEMODULATED OUTPUT ACCURACY TEST 4 38 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 33 PEAK DEVIATION AND RANGE SWITCH AD
116. 8 2 Model 8640B Option 004 8 18 Extender Board An extender board is sup plied with the generator that can be used to extend all circuit boards except AIOA2 Divider Assembly and the 12 Rectifier Assembly that are not accessible by removing a casting cover The RF Divider Assembly is self extending just re move the riser board and insert the RF Divider Assembly into the riser s slot Figure 8 1 lshows the extender board in use and the RF Divider Assem bly extended with Circuit Boards on Extenders Model 8640B Option 004 8 19 Wrench A wrench is supplied with the generator with one end that fits the SMC con nectors used on the generator s RF cables and the other end that fits another common SMC con nector that may be used in servicing 8 20 Spare Fuses The plastic box mounted on the chassis filter capacitors contains spare fuses for the power supply voltage regulators 8 21 Part Location Aids The locations of some chassis mounted parts and the major assemblies are shown on the last two foldouts in this manual The locations of individual components mounted on printed circuit boards or other assemblies are shown on the appropriate schematic diagram page or on the page opposite it The part reference designator is the assembly designator plus the part designator for example A6R9 is R9 on assembly For specific component description and ordering information refer to the parts list in Secti
117. 8 52 A26A8 Demodulation Amplifier Assembly Component Locations Demodulation Amplifier Schematic Diagram 8 49 AM Interconnections RF ON OFF Switch and Demodulation Amplifier A9 A26A8 SERVICE SHEET 15 Service SERVICE SHEET 16 PRINCIPLES OF OPERATION Vernier Attenuator A1 and A19A2 OUTPUT LEVEL Vernier A1R1 attenuates the AGC reference voltage and the superimposed AM modulation signal and drives the AGC Amplifier The potentiometer has a detent for the CAL position where the wiper is fully clockwise Resis tor A19A2R1 limits the low resistance end of the potentiometer Resistor A19A2R4 is switched into the AGC amplifier input line by S1AR in all but the highest OUTPUT LEVEL range On the highest OUTPUT LEVEL range A19A2R3 is switched in place of R4 and the AGC reference is increased by 6 dB a factor of 2 and the RF output is increased by 6 dB Meter Attenuator and Odd Range Code A19A2 The output of Meter Amplifier A26A4U1A Ser vice Sheet 12 is the RF LEVEL meter voltage Resistor A19A2R5 attenuates the amplifier output by 1 3 5 in the highest or 16 dBm OUTPUT LEVEL range Resistor A19A2R6 attenuates the output by 1 1 1 on ranges 8 to 15 Resistors A19A2R7 and R8 adjust the meter output attenuation to com pensate the meter for cumulative errors in the output attenuator on the high attenuation ranges Switching is done on SIB Switch S1AF gives closure to ground on all odd numbered ranges for use by
118. 9 2 SEE BACKDATING TABLES 7 1 7 2 a wl INPUTIOUTPUT Ww TO AM MOD MI et METER lt 2 SWITCH DETECTOR e ou 2 AM MOD R2 MODULATION 2 0 1 0 6 zT 2 AUDIO CN is HE lt RI OUTPUT LEVEL E REFERENCE DESIGNATIONS WITHIN OUTLINED 5 C0 ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER RT OF ASSEMBLY 222 2522 MXN ee I AIRI DESIGNATIONS OF OTHER COMPONENTS ARE ms W9 AT3 SODULATICNPHETENIMG MOTHER MEME UFTION O84 2 77 Figure 8 80 Modulation Metering Mother Board Schematic Diagram Figure 8 79 A13 Modulation Metering Mother Board Assembly Component Locations 2 of 2 8 49 Modulation Metering Mother Board A13 SERVICE SHEET 25 Service SERVICE SHEET A Al 9 Assembly Removal Procedure 1 Place instrument upside down and remove bottom cover see Service Sheet G CAUTION While working with and around the semi rigid coaxial cables in the generator do not bend the cables more than neces sary and do not torque the R F con nectors to more than 2 inch pounds 2 Remove flexible coupler 25 from the OUT PUT LEVEL 1 dB knob by loosening two set screws in the coupler 3 Using the wrench supplied in the instrument disconnect two semi rigid coaxial cables W10 at 19 1 1 28 and W11 at 19 1 2 26 4 Remove three p
119. A11R10 0757 0280 Al11R11 0757 0438 A11R12 0757 0438 Al1R13 0757 0438 211814 0698 0085 11 15 0757 0401 A11R16 0757 0401 Al1R17 0757 0401 A11R18 0757 0401 A11R19 0698 0024 A11R20 0698 0024 Al1R21 0698 0024 A11R22 0698 0024 A11R23 0757 1100 A11R24 0757 1100 Al1R25 0757 0442 A11R26 0757 0442 11 1 0340 1514 11 2 0360 1514 11 0360 1514 11 4 0360 1514 11 5 0340 1514 11 0360 1514 1101 1826 0007 11 1 1902 0049 Al1VR2 1902 0049 11 1 08640 60116 11 1 1 08640 20218 11 1 1 0698 8272 A11A1R2 0757 0479 A11A1R3 0698 8272 11 1 4 0757 0479 11 151 3100 3091 QTY TABLE 6 3 REPLACEABLE PARTS DESCRIPTION FIXED FREQUENCY MODULATION OSCILLATOR STANDARD MODULE CAPACITOR FXD 01UF 1 100WVDC MICA CAPACITOR FXD 100 1 300WVDC MICA CAPACITOR FXD 1000 75 10 25VDC AL CAPACITOR FXD 1000 75 10 25VDC AL CAPACITOR FXD 600 10 6VDC TA SOLID CAPACITOR FXD 150 10 20VDC TA SOLID CAPACITOR FXD 150 10 20VDC TA SOLID DIODE SWITCHING 2NS 30V 50MA DIODE SWITCHING 2NS 30V 50MA DIODE SWITCHING 2NS 30V 50MA TRANSISTOR NPN SI TO 39 PD 800MW INSULATOR XSTR TO 5 075 THK TRANSISTOR NPN SI TO 39 PD 800MW INSULATOR XSTR TO 5 075 THK TRANSISTOR NPN SI PD 300MW FT 200MHZ TRANSISTOR NPN SI TO 39 PD 800MW INSULATOR XSTR TO 5 075 THK TRANSISTOR NPN SI TO 39 PD 800MW INSULATOR XSTR TO 5 075 THK TRANSISTOR NPN SI PD 300MW FT 200MHZ NOT ASSIGNED RESISTO
120. A14 LABE INFO LINE VOLTAGE SELECTION CARD RISER ASSY GUIDE P C BOARD BROWN GUIDE P C BOARD RED GUIDE P C BOARD ORANGE CONNECTOR PC EDGE 15 CONT DIP SOLDER FAN MOTOR ASSY MOTOR ELEC BRUSHLES 10VDC 2550 PRM CONNECTOR PC EDGE HOOD CONNECTOR 6 CONT SOLDER EYE POWER SUPPLY MOTHER BOARD ASSY CONNECTOR PC EDGE 10 CONT DIP SOLDER CONNECTOR PC EDGE 15 CONT DIP SOLDER CONNECTOR PC EDGE 15 CONT DIP SOLDER CONNECTOR PC EDGE 15 CONT DIP SOLDER CONNECTOR PC EDGE 10 CONT DIP SOLDER CONNECTOR PC EDGE 10 CONT DIP SOLDER 5 2V REGULATOR amp FAN DRIVER ASSY CAPACITOR FXD 33UF 10 10VDC TA SOLID CAPACITOR FXD 510PF 5 100WVDC MICA CAPACITOR FXD 90UF 75 10 16VDC AL CAPACITOR FXD 2 2UF 10 20VDC TA CAPACITOR FXD 01UF 80 20 100WVDC CER DIODE SWITCHING 2NS 30V 50MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE SWITCHING 2NS 30V 50MA DIODE SWITCHING 2NS 30V 50MA DIODE PWR RECT 400V DIODE SWITCHING 2NS 30V 50MA DIODE SWITCHING 2NS 30V 50MA DIODE PWR RECT 50V 750MA DIODE PWR RECT 50V 750MA 750MA DIODE SWITCHING 2NS 30V 50MA DIODE SWITCHING 2NS 80V 200MA PHOTO DEVICE SW PNP S1 3V 05MW PD FUSE 2A 125V SLO BLO EXTRACTOR PC BOARD PIN DRIVE 0 250 LG YELLOW TRANSISTOR PNP SI CHIP PD 300MW TRANSISTOR NPN SI TO 39 PD 1W FT 15MHZ INSULATOR XSTR TO 5 075 THK THYRISTOR SCR JEDEC 2N3528 TRANSISTOR NPN SI TO 39 PD 800MW TRANSISTOR PNP SI CHIP TO 39
121. A26A1Q3 is normally on except in the pulse modulation mode Bandwidth Control A26A1 and A26A2 In the 2 4 and 4 8 MHz or LO BAND 2 frequency ranges capacitor A26A1C5 is switched in parallel with A26U1C3 by A26A1Q7 Transistor A26A1Q7 is a switch which operates in the inverted mode i e the emitter functions as a collector and the collector as an emitter The added capacitance of A26A1C5 reduces the amount of capacitor discharge between RF voltage peaks on the lower frequency bands and limits the AM bandwidth Capacitor A26A1C4 is also switched in for the 0 5 1 and 1 2 MHz or LO BAND 1 ranges by A26A1Q6 In the pulse modulation mode A26A1Q8 Q9 and Q5 switched on This switches out A26A1C4 and C5 and switches A26A1C6 in The Schmitt Trigger A26A2UI and U2A and A26U2B U2C and A26A1Q4 bias A26A1Q3 off between pulses which prevents A26A1C6 from discharging If were to discharge between pulse bursts the Modulator would be driven to maximum output when the next pulse arrived Switching of A26A1Q5 Q9 is multiplexed onto one line by transistors A26A2Q8 and Q9 Q8 is a switchable current source In LOW BAND 2 Q8 generates just enough current to turn on the collector base junction of Q7 In LOW BAND 1 the current increases enough to turn on both Q6 and Q7 because the voltage SERVICE SHEET 13 Cont d drop across A26A1R4 is enough to turn on Zener diode A26A1VR2 When the PULSE CODE line is low A26A2Q9 is on wh
122. A3A4C3 and A3A4C4 0180 0116 CAPACITOR FXD 6 8 UF 10 Add A3A4L1 and A3A4L2 9100 1664 COIL MOLDED RF CHOKE 3 mH 5 Page 6 25 Table 6 3 Add Al 1C24 0140 0145 CAPACITOR FXD 22PF 5 500 WVDC MICA Page 6 37 Table 6 3 Change A26A4CR7 CR8 CR9 and CR13 to 1901 0518 DIODE SCHOTTKY HOT CARRIER Page 6 4 Table 6 3 Add MP72 7120 4294 LABEL WARNING Service Sheet 5 component locations Replace Figure 8 22 with the attached figure P o A3A4 Figure 8 22 P O A3A4 Connector Board Assembly Component Locations P O Change 2 Continued 7 30 Model 8640B Option 004 08640 90073 CHANGE 2 Cont d Service Sheet 5 schematic Replace appropriate portion of schematic with attached partial schematic P Q_Figure 8 23 P O A3 RF OSCILLATOR ASSY 08640 60099 CONNECTOR BOARD ASSY 08640 60196 VARACTOR CATHODE X RF OSC 122 ON OFF INHIBIT VARACTOR ANODE P O Figure 8 23 RF Oscillator Simplified Diagram P O Change 2 Continued 7 31 Model 8640B Option 004 08640 90073 CHANGE 2 Cont d Service Sheet 6 component locations Replac _Figure 8 24 with the attached figure P O A3A4 Figure 8 24 P O Connector Board Assembly Component Locations P O Change 2 Service Sheet 9A schematic Add a 22 pF capacitor A11C24 parallel to 11 36 CHANGE 3 Table 6 3 Add 8 46 08640 00096 INSULATOR COUNTER HEAT SINK
123. A8A3U15 A8A3U16 A8A3U17 A8A3VR1 A8A3Y1 A8A3XA8A5 A8A4 A8A4DS1 A8A4DS2 A8A4J1 A8A4MP1 A8A4MP2 A8A4MP3 A8AA4PIA A8A4P1B A8A4Q1 A8A4R1 A8A4R2 A8A4R3 A8A4R4 A8A4R5 A8A4XDS1A A8A4XDS1B A8A5 A8A5XA8A2 A9 9 1 A9C2 A9C3 A9C4 A9C5 A9C6 A9C7 A9C8 2 9 4 9 5 0757 0438 0757 0279 0757 0399 0698 3437 0698 3160 0698 3444 0757 0280 0698 3440 3101 1730 0360 1514 1820 0054 1820 0077 1820 0368 1820 0511 1820 0661 1820 0661 1820 0174 1820 0054 1820 0054 1820 0600 1820 0600 1820 0055 1820 0986 1820 0986 1820 0986 1820 0600 1820 0600 1902 3203 1813 0006 1251 2035 08640 60025 2140 0356 2140 0016 1200 0471 1200 0472 03431 01201 03431 01201 03431 01201 1260 0363 1260 0364 1854 0071 2100 0647 2100 3216 0698 7277 0698 7276 1251 2194 1251 2194 08640 60028 1251 2035 08640 60117 0140 0191 0140 0191 0140 0191 0140 0191 0140 0191 0140 0210 0510 0052 1430 0759 1430 0772 1430 0773 1430 0774 QTY TABLE 6 3 REPLACEABLE PARTS DESCRIPTION RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 3 16K 1 125W F TUBULAR RESISTOR 82 5 OHM 1 125W F TUBULAR RESISTOR 133 OHM 1 125W F TUBULAR RESISTOR 31 6K 1 125W F TUBULAR RESISTOR 316 OHM 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 196 OHM 1 125W F TUBULAR SWITCH PB 5 CPDT
124. AC DC switch is in the DC position Multiply the given values by 5 to determine values when the switch is in the AC position NOTE DEMOD OUTPUT should be cali brated and a new DEMOD CAL Label filled in at least every three months to ensure accuracy Perform the follow ing adjustments and tests to determine values of ac voltage for new label 5 29 RF Detector Offset Adjustment 5 31 Preliminary AM adjustments 5 32 AM Accuracy Adjustment 4 38 Demodulated Output Accuracy Test MODULATION FREQUENCY seitch selects 400 Hz or 1000 Hz With Option 001 Variable Modulation Oscillator shown switch also selects multiplier Vernier with multiplier sets frequency from 20 Hz to 600 kHz AM INPUT OUTPUT 2000 ohm input for ex ternal AM 1 Vpk 0 7071 Vrms required for 100 modulation never more than 5 Vpk Input for pulse modulation 50 ohm gt 1 Vpk positive pulse required to turn on RF Output for internal oscillator whenever AM selector is set to INT 600 ohm source impedance level controlled by AUDIO OUTPUT LEVEL NOTE With the Option 001 Variable Modula tion Oscillator AM OUTPUT and FM OUTPUT are in parallel Parallel load should be 2600 ohms MODULATION vernier varies amplitude modula tion from 0 to 100 as indicated on the meter AUDIO OUTPUT LEVEL control varies level of signal from AM and or FM OUTPUT jacks cal ibration gives voltage into 6000 LINE switch applies or removes AC power T
125. ALLOCATION Section I INTRODUCTION D 1 General This appendix provides a summary of the maintenance operations for the SG 1112 V 1 U and SG 1112 V 2 U It authorizes categories of mainte nance for specific maintenance functions on repairable items and components and the tools and equipment re quired to perform each function This appendix may be used as an aid in planning maintenance operations D 2 Maintenance Function Maintenance fumctions will be limited to and defined as follows a Inspect To determine the serviceability of an item by comparing its physical mechanical and or electrical characteristics with established standards through ex amination b Test To verify serviceability and to detect incipient failure by measuring the mechanical or electrical charac teristics of an item and comparing those characteristics with prescribed standards c Service Operations required periodically to keep an item in proper operating condition i e to clean decon taminate to preserve to drain to paint or to replenish fuel lubricants hydraulic fluids or compressed air sup plies d Ajust To maintain within prescribed limits by bringing into proper or exact position or by setting the operating characteristic to the specified parameters e Align To adjust specified variable elements of an item to bring about optimum or desired performance f Calibrate To determine and cause corrections to be made or to
126. AM INPUT o and DEMOD OUTPUT set AM to DC and ensure that the DEMOD OUTPUT is feeding into less than 30 pF at the external VOR ILS audio oscillator input NOTE AM accuracy is specified except when the OUTPUT LEVEL 10 dB switch is in the 16 dBm position Percent AM is indicated on the front panel meter when Meter Function is in the AM position A more precise method of determining percent AM is provided by the DEMOD OUTPUT feature With the OUTPUT LEVEL VERNIER in the CAL detent position percent AM is directly proportional to the ac voltage at the DEMOD OUTPUT 5 AC DC switch to 20 Vrms AC DC switch to DC 100 per Vrms Vdc 1 414 0 010V Figure 3 7 Setting the Modulation Controls 2 of 5 3 17 Operation Model 8640B Option 004 SETTING MODULATION ENG TURE EET When the OUTPUT LEVEL vernier is out of the CAL detent and the internal AC DC switch is in the DC position percent AM can be derived by applying the following formula Vrms AM 100 2 Vdc Pulse Modulation Set Meter Function o to LEVEL b Set AM to PULSE this disables the RF output Apply the modulation pulse gt 0 5V to the AM INPUT jack e 50 ohm load impedance The Signal Generator requires a positive level to produce an RF output c Set the desired pulse on level using the OUTPUT LEVEL controls Frequency Modulation Set Meter Function to FM To use the intemal modulatio
127. Adjustments ADJUSTMENTS 5 44 INTERNAL REFERENCE FREQUENCY ADJUSTMENT Cont d PROCEDURE l Remove trim strip that holds front panel window in place Gently pull window up and out and remove it Allow generator to warm up for 2 hours Connect equipment as shorn Figure 5 15 setting Signal Generator s controls as follows TIME BASE REF INT EXT on rear panei Ew TIME BASE VERNIER ww e CAL Set oscilloscope s vertical sensitivity to 0 05 V div at and horizontal scale for external ac Set magnifier for X 10 and adjust oscilloscope s controls for a Lissajous figure Adjust time base adjustment pot available through the hole in the front of the counter casting for a stable 2 1 Lissajous figure it will look approximately like a figure eight on its side Replace front panel window and trim strip 5 43 5 44 Model 8640B Option 004 Replaceable Parts SECTION VI REPLACEABLE PARTS 6 1 INTRODUCTION 6 2 This section contains information for odering parts Table 6 2 lists abbreviations used in the parts list and throughout the manual Table 6 3 lists all replaceable parts in reference designator order moan the names and addresses that correspond to the manufacturer s code numbers 6 3 EXCHANGE ASSEMBLIES 6 4 Table 6 lists assemblies within the instru ment that may be replaced on an exchange basis thus affording a considerable cost saving Ex change factory re
128. Band Filters of the band This is necessary to effectively remove the second harmonic on the lower half of the band The midpoint of the band is sensed by a Schmitt Trigger which compares a reference voltage to a voltage propor tional to the frequency tuning On the four lowest frequency ranges the RF signal has little second harmonic content because of good waveform symmetry therefore each range has only one filter AM AGC Circuits Service Sheets 12 and 13 The output of the RF Filters is amplified by the Output Amplifier The amplifier s output is peak detected and buffered by the Detec tor Buffer Amplifier The detected voltage which is negative is buffered and amplified by the Demodulation Amplifier which drives DEMOD OUTPUT The detected voltage is also summed in the Summing Amplifier with a positive AGC reference voltage from the OUTPUT LEVEL vernier The AGC reference may also have the amplitude modulation voltage superimposed on it The sum of the detector and reference voltages is amplified by the Summing and Modulator Driver Amplifiers The Modulator Driver Amplifier supplies control current to the Modulator which adjusts the RF output level In the pulse modulation mode the Modulator Driver Amplifier is switched on and off by input pulses from the Schmitt Trigger To maintain a constant detector voltage into the summing amplifier the peak detector s output voltage is sampled during the RF on period and then stored in the
129. Buffers U7 through U12 With an open at the Vcc Supply the Storage Buffer outputs are open which represents a high to each display input The displays generate a blank when all inputs are high When no error exists Q3 is held on by Q4 which is also on and is at 59V TROUBLESHOOTING It is assumed that a problem has been isolated to the up down counter and display circuits as a result of using the trouble SERVICE SHEET 20 Cont d shooting block diagrams Troubleshoot by using the test equip ment listed below performing the initial test conditions and control settings and following the procedures outlined in the table NOTE The following tests depend upon the counter RF scaler circuits shown on Service Sheet 18 and the counter time base circuits shown on Service Sheet 19 working correctly Test Equipment Digital Voltmeter 2 HP 3480D 3484A Oscilloscope HP 180A 1801A 1820C Frequency Counter HP 5327C Test 652 Initial Test Conditions Top cover removed see Service Sheet G for removal procedure 8 Counter Lock Assembly casting cover removed and Counter Lock Board Assembly removed and extended for service see Service Sheet C for procedures Connect the test oscillator 50 ohm output to COUNTER INPUT set it for 500 mVrms Initial Control Settings COUNTER MODE EXPAND Oft LOCK
130. C4 1 8 T0 1472 F C4 1 8 T0 1002 F C4 1 8 T0 1472 F 4 1 8 0 5111 C4 1 8 T0 1963 F C4 1 8 T0 3831 F C4 1 8 T0 9092 F C4 1 8 T0 5111 F C4 1 8 T0 5111 F C4 1 8 T0 1781 F MF4C1 8 T0 6191 F C4 1 8 TO 1961 F C4 1 8 T0 5112 F 4 1 8 0 5111 C4 1 8 T0 5112 F C4 1 8 T0 4221 F C4 1 8 T0 1002 F C4 1 8 T0 8251 F MODEL 8640B OPTION 004 REFERENCE DESIGNATION A26A4R31 A26A4R32 A26A4R33 A26A4R34 A26A4R35 A26A4R36 A26A4R37 A26A4R38 A26A4R39 A26A4R40 A26A4R41 A26A4R42 A26A4R43 A26A4R44 A26A4R45 A26A4R46 A26A4R47 A26A4R48 A26A4R49 A26A4R50 A26A4R51 A26A4R52 A26A4R53 A26A4R54 A26A4R55 A26A4R56 A26A4R57 A26A4TP1 A26A4TP2 A26A4TP3 A26A4TP4 26 4 5 26 4 6 A26A4TP7 A26A4TP8 26 401 A26A4U2 A26A4U3 26 404 A26A4VR1 A26A4VR2 A26A5 A26A5XA26A6 A26A6 A26A6XA26A2 A26A6XA26A4 A26A6XA26A8 A26A7 A26A8 26 8 1 A26A8C2 A26A8C3 A26A8C4 A26A8C5 A26A8C6 A26A8MP1 A26A8MP2 A26A8R1 A26A8R2 A26A8R3 A26A8R4 A26A8R5 A26A8R6 A26A8R7 A26A8R8 A26A8R9 A26A8R10 HP PART NUMBER QTY 0698 3447 0757 0279 0757 0438 0757 0465 0757 0465 0698 0083 0698 3153 0757 0280 0757 0346 0757 0465 0757 0465 0698 0083 0698 3450 0757 0442 0698 3154 0757 0401 0757 0289 0698 3150 0698 3451 1 0757 0280 0757 0278 0757 0421 0757 0280 0757 0442 0757 0421 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360
131. CAPACITOR FXD 19 10 35VDC TA SOLID 19 10 35VDC TA SOLID 19 10 35VDC TA SOLID 19 10 35VDC TAOSOLID 19 1 35VDC TA SOLID CAPACITOR FXD 1000PF 10 1000WVDC CER CAPACITOR FXD 2 20 10 20VDC CAPACITOR FXD 2 20 10 20VDC CAPACITOR FXC 1000 F 10 1000WVDC CER DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA PART OF ETCHED CIRCUIT BOARD NOT ASSIGNED COIL FXD MOLDED RF CHOCKE 15UH 10 COIL FXD MOLDED RF CHOKE 1UH 10 COIL FXD MOLDED RF CHOKE 33UH 20 COIL FXD MOLDED RF CHOKE 68UH 10 COIL FXD MOLDED RF CHOKE 1 2UH 10 COIL FXD MOLDED RF CHOKE 2 2UH 10 COIL FXD MOLDED RF CHOKE 5 6UH 10 COIL FXD MOLDED RF CHOKE 10UH 10 COIL FXD MOLDED RF CHOKE 15UH COIL FXD MOLDED RF CHOKE 15UH COIL FXD RF CHOKE 43UH 5 COIL FXD MOLDED RF CHOKE 15UH 10 COIL FXD MOLDED RF CHOKE 15UH 10 COIL FXD RF CHOKE 43UH 5 TRANSISTOR NPN SI PD 300MW FT 200MHZ TRANSISTOR PNP SI CHIP TO 18 PD 360MW TRANSISTOR PNP SI CHIP TO 18 PD 360MW TRANSISTOR PNP SI CHIP TO 18 PD 360MW TRANSISTOR NPN 2N5179 SI PD 200MW RESISTOR 51 1 OHN 1 125W F TUBULAR RESISTOR 51 1 OHM 1 125W F TUBULAR RESISTOR 51 1 OHM 1 125W F TUBULAR RESISTOR 10 OHM 1 5W F TUBULAR RESISTOR 5 1K 1 125W F TUBULAR R
132. CAPACITOR FXD 5500PF 0 200WVDC CER CAPACITOR FXD 5500PF 0 200WVDC CER CAPACITOR FXD 5500PF 0 200WVDC CER CONNECTOR RF SMC M SGL HOLE FR CONNECTOR RF SMC N SGL HOLE FR COVER BUFFER BOARD SCREW MACH 4 40 PAN HD POZI REC SST 300 WASHER FL MTLC NO 4 125 IN ID 281 IN GASKET RFI COVER BUFFER BOARD GASKET RFI SCREW MACH 4 40 PAN HD POZI REC SST 300 WASHER FL MTLC NO 4 125 IN ID 281 IN NUT HEX DBL CHAM 10 20 THD 109 THK WASHER LK INTL T NO 10 195 IN ID 381 NUT HEX DBL CHAM 10 32 THD 109 THK WASHER INTL T NO 195 IN ID ID 381 SCREW MACH 4 40 PAN HD POZI REC SST 300 WASHER LK HLCL NO 4 115 IN IC 226 IN WASHER LK HLCL NO 4 115 IN ID 226 IN SCREW MACH 4 40 PAN HD POZI REC SST 300 VARACTOR HEAD FILTER ASSY NRFR MODEL 8640B OPTION 004 MFR CODE 04713 04713 28480 28480 97464 97464 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 07700 97464 28480 28480 28480 78189 28480 78189 28480 28480 73734 28480 28480 79136 28480 71450 28480 01121 01121 01121 01121 01121 01121 2K497 2K497 28480 28480 28480 07700 28480 07700 28480 28480 28480 78189 28480 78189 28480 28480 28480 28480 MFR PART NUMBER SZ 10939 110 SZ 10939 182 08640 60099 08640 60098 7100 12 CD 3100 43 ST CD 1430 0537 1430 0759 08640 00085 08640 20106 8160 0233 08640 20106 08640 20224 08640 60206 2200 0151 2190 0019 20 90044 3100 43
133. CB5155 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 LM301AH LM301AH 517400 SN7408N SZ 10939 182 SZ 10939 182 08640 60029 0160 2228 0160 2228 150D685X903582 150D157X9006R2 30D105G1508A2 150D225X9020A2 150D685X903582 30D505F150CC2 0160 0939 1901 0025 REPLACEABLE PARTS REFERENCE DESIGNATION ASCR6 5 7 ASCR8 A5CR9 5 10 5 11 ASCR12 A5CR13 5 1 ASMP1 ASMP2 501 502 A503 A504 505 506 507 A508 A5Q9 A5Q10 5011 5012 ASR1 A5R2 A5R3 ASR4 ASRS ASR6 ASR7 ASR8 A5R9 A5R10 ASR11 A5R12 A5R13 A5R14 A5R15 ASR16 A5R17 A5R18 A5R19 A5R20 A5R21 A5R22 A5R23 A5R24 A5R25 A5R26 A5R27 A5R28 A5R29 A5R30 HP PART NUMBER 1901 0025 1901 0025 1901 0025 1901 0025 1901 0050 1901 0050 1901 0050 1901 0025 0490 1078 4040 0750 1480 0073 4040 0756 1480 0073 1854 0221 1854 0221 1854 0404 1854 0404 1853 0038 1205 0011 1200 0173 1853 0038 1205 0011 1200 0173 1853 0038 1200 0173 1854 0039 1200 0173 1205 0011 1854 0022 1200 0173 1854 0237 0510 0002 1205 0085 2360 0199 2420 0003 2190 0018 2190 0007 1853 0012 1200 0173 1854 0237 0510 0002 1205 0085 2360 0199 2420 0003 2190 0018 2190 0007 0698 3162 0757 0180 0757 0403 0757 0290 0757 0317 0698 3132 0698 3410 2100 3164 0698 0085 0757 0317 0698 3132 0757 0290 0757 0180 0757 0403 0698 3162 0757 04
134. Crystal Oscillator Y1 is a b MHz crystal oscillator which can be voltage tuned over a 100 Hz range The tuning voltage comes from the TIME BASE VERNIER potentiometer ABA4R Service Sheet 21 The oscillator output is ORed with the INT EXT time base switch 83 The output of OR gate UGB follows the oscillator frequency when 53 is ground INT or is high when 53 is open EXT An external time base reference if present is ac coupled into the output of U6B Transistor Q1 is a buffer amplifier and drives the 5 counter 012 Time Base Reference Decoder A8A3 Depending on the COUNTER MODE and RANGE selected the time base reference frequency is divided by counters U13 U14 and U15 which are programmed by the Preset Decoders The division ratio is given in Table 8 6 The Qp output of U12A drives synchronously loading counters U13 and U14 which together form a program mable 25 32 or 40 counter The counters work as follows At the last count of a 99 count sequence the load inputs LD are enabled with a 1ow The next count input presets the counters to the BCD count at the data inputs DA Dp Dc Dp Counter U13 then counts the clock input T pulses beginning at the preset count When the count reaches nine the counter generates a high carry output TC pulse The carry pulse enables CE counter U14 for one clock period which increments the count of U14 by one Counter U13 then counts from zero to nine and generates another carry pulse
135. DBL CHAM 15 32 32 THD 078 THK WASHER LK INTL T 505 IN ID 63 IN OD RIVET BLIND DOME HD 0 125 DIA GUIDE P C BOARD BLUE RESISTOR 1K 1 5W F TUBULAR OUTPUT AMPLIFIER NSR PART OF A26U1 NSR PART OF A26U1 NSR PART OF A26U1 NSR PART OF A26U1 NSR PART OF A26U1 NSR PART OF A26U1 NSR PART OF A26U1 MODULATOR PREAMPLIFIER CABLE COAX 086 OD CABLE COAX 50 OHM 086 OD CABLE COAX 086 OD CABLE COAX 086 OD BOARD ASSY OUTPUT AMPLIFIER CAPACITOR FXD 1UF 10 100WVDC CER CAPACITOR FXD 1UF 10 100WVDC CER CAPACITOR FXD 1UF 10 100WVDC CER CAPACITOR FXD 200PF 5 300WVDC MICA CAPACITOR FXD 100PF 5 300WVDC MICA CAPACITOR FXD 2 2UF 10 20VDC TA DIODE SWITCHING 2NS 30V 50MA DIODE STABISTOR 10V 250MA DIODE SWITCHING 2NS 30V 50MA DIODE SWITCHING 2NS 30V 50MA DIODE SWITCHING 2NS 30V 50MA DIODE SCHOTTKY COIL FXD MOLDED RF CHOKE 15UH 10 COIL FXD MOLDED RF CHOKE 2 7UH 10 TRANSISTOR PNP 2N23251 SI CHIP TRANSISTOR JFET DUAL N CHAN D MODE SI TRANSISTOR J FET N CHAN D MODE SI TRANSISTOR PNP 2N3251 SI CHIP TRANSISTOR NPN SI PD 300MW FT 200MHZ TRANSISTOR NPN SI TRANSISTOR NPN SI TRANSISTOR NPN SI TRANSISTOR NPN SI PD 300MW PD 300MW PD 300MW PD 300MW FT 200MHZ FT 200MHZ FT 200MHZ FT 200MHZ RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 422 OHM 1 383 OHM 1 125W 750 OHM 1 125W 1 33K 1 125W F 750 OHM 1 125W 125W F TUBULAR F TUBULAR F TUBULAR TUBULAR F TUBULAR RESIST
136. DVM to the reading noted in step 14 then continue The DVM should read 500 mVdc x 1 dB 4 44 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 26 OUTPUT LEVEL ACCURACY TEST Complete Cent d IF Attenuator dB 30 Set Level 20 445 6 561 0 10 445 6 561 0 445 6 561 0 Test Generator DVM Readings OUTPUT LEVEL mVdc 16 Set the IF attenuator to 20 dB and use analyzer s display sensitivity controls to set the DVM to the reading noted at the 131 dBm step above then continue The DVM should read 500 mVdc 1 dB IF Attenuator Test Generator DVM Readings dB OUTPUT LEVEL mVdc 20 131 dBm Set Level 10 141 dBm 445 6 561 0 17 Verify the test accuracy by increasing the RF attenuator by 10 dB The DVM should drop below 300 mVdc If it does not check the test setup for RF leakage paths 18 Check output level accuracy at other output frequencies by setting the two generators for a 3 MHz difference frequency and repeating steps 1 through 17 4 27 OUTPUT LEVEL FLATNESS TEST SPECIFICATION Level F atness t 0 75 dB from 0 5 to 512 MHz referred to output at 190 MHz lt 0 5 dB from 108 to 336 MHz referred to output at 190 MHz Flatness applies to 10 to 10 dBm MODEL 8640B OPTION 004 POWER METER Figure 4 12 Output Level Flatness Test Setup 4 45 Performance Tests PERFORMANCE TESTS 4 27 OUTPUT LEVEL FLATNESS TEST Cont d EQUIPMENT
137. Deficiencies Fill out and forward Standard Form 364 Report of Dis crepancy ROD as prescribed in AR 735 11 2 NAVSUPINST 4440 127E AFR 400 54 MCO 4430 3E and DLAR 4140 55 c Discrepancy in Shipment Report DISREP SF 361 Fill out and forward Discrepancy in Shipment Re port DISREP SF 361 as prescribed in AR 55 38 NAVSUPINST 4610 33B AFR 75 18 MCO P4610 19C and DLAR 4500 15 0 4 Reporting Equipment Improvement Recommendations EIR If your equipment needs improvement let us know Send us an EIR You the user are the only one who can tell us what you don t like about your equipment Let us know what you don t like about the design Tell us why a procedure is hard to perform Put it on an SF 368 Quality Deficiency Report Mail it to Commander US Army Communications and Electronics Materiel Redness Command and Fort Monmouth ATTN DRSEL ME MQ Fort Monmouth NJ 07703 We ll send you a reply 0 5 Administrative Storage Administrative storage of equipment issued to and used by Army activities shall be in accordance paragraph 2 22 0 6 Destruction of Army Electronics Materiel Destruction of Army electronics materiel to prevent enemy use shall be in accordance with TM 750 244 2 General Information Model 8640B Option 004 MODEL 8640B OPTION 004 RACK MOUNTING KIT DEMO CAL LABELS LINE POWER CABLE Figure 1 1 HP Model 8640B Option 004 Signal Generator Option 001 and Accessories Supplied 1
138. End of Band 512 1024 MHz 256 512 MHz 128 256 MHz 64 128 MHz 32 64 MHz 16 32 MHz 8 16 MHz 4 8 MHz 2 4 MHz 1 2 MHz 0 5 1 MHz High End of Band 512 1024 MHz 256 512 MHz 128 256 MHz 64 128 MHz 32 64 MHz 16 32 MHz 8 16 MHz 4 8 MHz 2 4 MHz 1 2 MHz 0 5 1 MHz Frequency Accuracy and Fine Tune Test Counter Readings Difference X10 TIME BASE VERN not CAL cw TIME BASE VERN not CAL ccw FINE TUNE Frequency Stability vs Time and Restabilization Time Test Time After frequency change After band change After RF ON OFF set to ON 4 94 Model 8640B Option 004 Table 4 4 Performance Test Record 2 of 9 Test Description Frequency Stability vs Temperature Test Frequency Stability vs Line Voltage Test 5 to 10 Line Voltage Frequency Stability Test Load Level Mode Harmonics Test Frequency Range 0 5 1 MHz 1 2 MHz 2 4 MHz 4 8 MHz 8 16 MHz 16 32 MHz 32 64 MHz 64 128 MHz 128 256 MHz 256 512 MHz Sub Harmonics and Non Harmonic Spurious Test Below carrier Single Sideband Phase Noise Test At 550 MHz gt 112 dB down At 450 MHz gt 120 dB down Single Sideband Broadband Noise Floor Test gt 130 dB down Performance Tests Performance Tests Model 8640B Option 004 Table 4 4 Performance Test Record 3 of 9 Test Description Residual AM Test gt 78 dB down gt 85 dB down Residual FM Test lt 7 5 Hz 7 5 mVrms 2 5 Hz 2 5 mVrms lt 7 5 Hz 7 5 mVrms
139. FT 200MHZ SI PD 300MW FT 200MHZ SI CHIP PD 300MW SI PD 300MW FT 200MHZ SI PD 300MW FT 200MHZ SI CHIP PD 300MW SI CHIP PD 300MW SI PD 300MW FT 200MHZ HM 1 125W F TUBULAR 1 125W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 5 25W CC TUBULAR 5 25W CC TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR 05W F TUBULAR 2 05W F TUBULAR 1 125W F TUBULAR 05W F TUBULAR 05 W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR REPLACEABLE PARTS MFR MFR PART NUMBER CODE 28480 0160 3455 28480 0160 3466 28480 0160 2207 28480 0160 3877 28480 0160 3879 28480 0160 3879 28480 0160 0174 28480 0160 3094 28480 0160 2201 56289 150D105X9035A2 56289 150D225X9020A2 28480 0160 3879 56289 150D225X9020A2 28480 0160 2055 28480 0160 2055 28480 0160 2055 28480 0160 2204 28480 0160 3876 28480 0160 3876 28480 0160 3876 28480 0160 3456 28480 1901 0040 28480 1901 0040 24226 15 242 24226 15 152 28480 1854 0071 28480 1853 0020 28480 1853 0020 28480 1854 0071 28480 1854 0071 28480 1855 0062 28480 1853 0020 28480 1854 0071 28480 1854 0071 28480 1854 0071 28480 1854 0071 28480 1854 0071 28480 1853 0020 28480 1854 0071 28480 1854 0
140. Filter HP 08640 60502 10dB Step Attenuator HP 355D 20dB Amplifier e sos os os o s s s s HP 84A Spectrum Analyzer HP 141 T 8552B 8554B PROCEDURE l Connect equipment as shown in Figure 4 5 after setting Signal Generator s controls as follows Meter Function COUNTER MODE E x P AND LOCK Source AM FM EE RANGE FREQUENCY TUNE OUTPUT LEVEL Switches OUTPUT LEVEL Vernier RF ON OFF LEVEL off off INT OFF OFF 128 256 MHz 260 MHz 10 dBm CAL 2 Set step attenuator to 60 dB Set analyzer s input attenuation to 0 dB scale switch to log 10 dB div and reference level controls to 30 dBm set resolution bandwidth to 30 kHz frequency span per division scan width to 1 MHz and tune the frequency controls to set 260 MHz at the center of the display Adjust reference level vernier to set signal peak to top reference graticule line on display 3 Set generator s RANGE switch to 256 512 MHz Tune analyzer to display the 520 MHz signal 1 the second harmonic of 260 MHz 4 Tune generators FREQUENCY TUNE for a minimum signal on analyzer s display Set the step attenuator to O dB and again tune FREQUENCY TUNE for a minimum signal 5 The signal on the display should be below the top reference level graticule line Tune the spectrum analyzer slowly to 500 kHz All non harmonic spurious signals and su ha monics should be below the 40 dB g
141. GEAR SPUR GEAR PLANET GEAR COMBINATION GEAR COMBINATION MFR CODE 24546 24546 24546 16299 16299 16299 24546 16299 28480 28480 01295 01295 01295 01295 01295 01295 01295 01295 01295 27014 27014 01295 27014 27014 27014 27014 27014 04713 28480 71785 28480 71744 71744 28480 28480 28480 28480 28480 28480 28480 28480 01121 32997 24546 24546 00779 00779 28480 71785 28480 72136 72136 72136 72136 72136 72136 97464 28480 28480 28480 28480 REPLACEABLE PARTS MFR PART NUMBER C4 1 8 TO 5111 F C4 1 8 TO 3161 F C4 1 8 TO 82R5 F C4 1 8 TO 133R F C4 1 8 TO 3162 F C4 1 8 TO 316R F C4 1 8 TO 1001 F C4 1 8 TO 196R F 3101 1730 0360 1514 SN7400N SN7474N SN7496N SN7408N SN7432N SN7432N SN7404N SN7400N SN7400N DM74L90N DM74L90N SN7490N DM86L75N DM86L75N DM86L75N DM74L90N DM74L90N SZ 10939 230 1813 0006 252 15 30 300 08640 60025 CM7 7683 683 1200 0471 1200 0472 03431 01201 03431 01201 03431 01201 1260 0363 1260 0364 1854 0071 GS4G120P502MZ 3339H 1 103 C3 1 8 TO 5112 G C3 1 8 TO 4642 G 3 331272 0 3 331272 0 08640 60028 252 15 30 300 08640 60117 DM15E560J0300WVICR DM15E56030300WV1CR DM15E56030300WV1CR DM15E56030300WV1CR DM15E56030300WV1CR DM15F271J0300WV1CR 7100 12 CD 1430 0759 1430 0772 1430 0773 1430 0774 MODEL 8640B OPTION 004 REPLACEABLE PARTS TABLE 6 3 R
142. Hz 3 Calibrate the recorder for a zero to full scale reading that corresponds to a 000 to 999 Hz reading of the frequency counter s last three digits 1 1 kHz full scale 4 Warm up the equipment for two hours Establish a reference on the recorder and record the generator s output frequency for 10 minutes The frequency change in 10 minutes should be 500 Hz half of full scale 500 Hz 5 Set the FREQUENCY TUNE control fully and back again to approximately 50 MHz After 15 minutes record the frequency for 10 minutes The frequency change in 10 minutes should be 500 Hz 500 Hz 6 Set RANGE to 16 32 MHz and record the frequency for 10 minutes The frequency change in 10 minutes should be 250 Hz 250 Hz 7 Set RANGE to 32 64 MHz and set RF ON OFF to OFF After one minute set RF ON OFF to ON Record the frequency for 10 minutes The frequency change for 10 minutes should be 500 Hz 500 Hz NOTE If the instrument has been wired to switch the RF Oscillator off with RF ON OFF switch wait 10 minutes after switching RF mode to ON before continuing with step 7 4 17 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 16 FREQUENCY STABILITY VS TEMPERATURE TEST SPECIFICATION Stability vs Temperature lt 50 normal mode NOTE Stability specifications for phase lock mode are determined by counter time base reference See the internal reference tests DESCRIPTION A frequenc
143. Hz to 500 kHz HP 8003A P T Output 21V into 500 Pulse Width down to 1 us Transition Time 50 ns Output 1 MHz level compatible with HP 105B Frequency Counter HP 3400A Stability lt 5 x 10715 24 hours lt 5 x 10 Performance Adjustments T Troubleshooting Quartz Oscillator RMS Voltmeter 1 16 tjs Range 10 Hz to 100 kHz Reading True rms ac only Voltage Range 1 mV to 10V full scale Accuracy 1 of full scale 50 Hz to 50 kHz Scale Voltage and dB Model 8640B Option 004 Signal Generator Audio Spectrum Analyzer Spectrum Analyzer P Performance A Adjustments T Troubleshooting General Information Table 1 2 Recommended Test Equipment 4 of 6 Instrument Type Critical Specifications Suggested Model Use Range 0 45 550 MHz Output gt 13 dBm into 500 Drift 20 ppm 10 min SSB Phase Noise 7130 dB down from 230 to 450 MHz increasing linearly to 122 dB down at 550 MHz stated in a 1 Hz band width at 20 kHz offset from carrier and de creasing approximately 6 dB octave for each divided down range but need not be less than 140 dB down Residual FM 15 Hz rms in 20 Hz to 15 kHz post detection noise bandwidth lt 5 Hz rms in 0 3 3 kHz post detection noise bandwidth Aux RF Out gt 5 dBm Leakage 3 induced in a 2 turn 1 inch diameter loop 1 inch away from any sur face and measured into a
144. Initial conditions and settings Connect high impedance input of frequency counter to TPL to ON Set COUNTER MODE LOCK 781 25 Hz i e division by 78 125 Hz i e division by 100 77 35 liz i e division by 101 18 125 Hz ie division by 100 Check U10 1 11 and associated circuitry _ DECIMAL POINT DECODER 8 56 Initial conditions and settings Set RANGE and COUNTER MODE switches as shown in Table 8 9 8 9 Decimal Point outputs high or decimal points lit as indi cated in the table Check U2 U3 and ciated circuitry Also check AR Ad Ul see Service Sheet 20 PIO A 3 ASSY PIO A8 COUNTER LOCK ASSEMBLY 0860 80119 08640 40057 PIO PEAK RANGE SWITCH ASSY 08640 60117 ee ee ASE REFERENCE DECODER IME BASE 9 Lo lyf 1mH el PRESET DECODER s fmm 1 2 4 5 f tn Ponce E cal mmm BASE REFERENCE CRYSTAL OSC mmm npo 1 1 ares DELODER eS eS eee A i Ulli Si t A oid 6 C26 QUE 29 1 0 01 pF nct Pee Cont E 21 CODE B tt DESI 01yF F 5 2 cM 18 Cl R16 co om l imh Tour 5110 CRI our AN TIME BASES 1
145. Input Code 1248 with 1 on state positive Option 002 compatible with Frequency Counter Output Compatible with Strip Chart Recorder Directional Coupler Range 100 550 MHz HP 778D Coupling Attenuation 20 dB Option 12 Directivity 36 dB VSWR 1 1 1 Distortion Analyzer Range 20 Hz to 600 kHz HP 338A Distortion Range lt 0 1 a Minimum Input lt 300 mVrms FM Discriminator Ranges 100 kHz to 10 MHz HP 52104 Linear Analog Output 1V for fuil scale Filter Kit Output Low Pass Filters for HP 5210A FM HP 10531A Discriminator 20 kHz and 1 MHz Butter worth filters 600 Ohm Feedthrough Impedance 6009 1 shunt HP 11095A Connectors BNC 520 0 1040 MHz Notch Notch Frequency Accuracy 500 540 MHz HP 08640 60502 Filter Notch Rejection gt 60 dB See Figure 1 7 4 MHz Low Pass Filter 4 MHz low pass 3 pole CIR Q TEL 2 required Impedance 502 FLT 21B 4 3 VSWR lt 1 5 1 50 3A 3B Ripple lt 0 2 dB 1 5 MHz Low Pass 1 5 MHz low pass 3 pole CIR Q TEL Filter Impedance 509 FLT 21B 1500K VSWR 1 5 1 3 50 3A 3B Ripple lt 0 2 dB 15 kHz Low Pass Filter 15 kHz low pass 7 pole CIR Q TEL Impedance 500 FLT 21B 15K Ripple lt 0 2 dB 7 50 3A 3B 3 kHz Low Pass Filter 3 kHz low pass 5 pole CIR Q TEL Impedance 500 FLT 21B 3K Ripple lt 0 2 dB 5 50 3A 3B Frequency Counter Range to 550 MHz HP 5327C Input Sensitivity lt 100 mV Inputs 50Q and high impedance 1 MQ P Performance A Adju
146. It explains how to set the frequency amplitude and modulation controls and covers such operator maintenance as fuse and indicator lamp replacement and fan filter cleaning 3 3 PANEL FEATURES 3 4 Front panel controls indicators and con nectors are shown and described in Figure 3 2 The Internal AC DC Switch is described in Figure 3 2 Rear panel controls and connectors are shown and described i 3 5 OPERATOR S CHECKS 3 6 Use the operator s checks Figure 3 5 to verify proper operation of the Signal Generator s main functions 3 7 OPERATING INSTRUCTIONS 3 8 Figures 3 6 and 3 7 explain how to set the frequency amplitude and modulation controls Figure 3 6 Jalso explains how to use the frequency counter and phase lock controls 3 9 OPERATOR S MAINTENANCE 3 10 Fuse The main ac line fuse is located on the rear panel next to the line power cable jack To remove the fuse first remove the line power cable from its jack Slide the fuse compartment cover to the left then pull the handle marked FUSE PULL and remove the fuse CAUTION Be sure to select the correct fuse rating for the selected line voltage see LINE VOLTAGE SELECTION ii Section fuse ratings are listed on the fuse com partment 3 11 Fan The cooling fan s filter is located on the rear panel To service the filter use a No 2 pozidriv screwdriver HP 8710 0900 to remove the four screws that hold the falter to the rear panel
147. MHz 2 287 KHz 16 32 MHz 2 287 kHz 8 16 MHz 2 287 kHz 4 8 MHz 2 287 kHz 4 101 _ Performance Tests Model 8640B Option 004 Table 4 4 Performance Test Record 9 of 9 Para mu Results No Test Description Max Counter External Sensitivity Test 0 5 to 550 MHz 20 Hz to 500 kHz V internal Reference Accuracy Test 15 C to 35 C 4 999 995 Hz 5 000 005 Hz 0 C to 55 c 4 999 985 Hz 5 000 015 Hz Internal Reference Drift Rate Stability Test Time 0 27 Hz Voltage 0 52 Hz Temperature 10 2 Hz Load V no change Level Change V no change Mode Change V no change Phase Lock Restabilization Time Test After two hour warmup After frequency change After band change After 1 min in RF OFF mode 4 102 Model 8640B Option 004 Adjustments SECTION V ADJUSTMENTS 5 1 INTRODUCTION 5 2 This section describes adjustments required to return the Model 8640B Option 004 Signal Gener ator to peak operating condition when repairs are required Included in this section are test setup and check and adjustment procedures Removal and replacement procedures are given on the alphabetic service sheets after the schematics in ection VIII Adjustment location photographs are given on the last foldouts in Section VIII 5 3 SAFETY CONSIDERATIONS 5 4 Although this instrument has been designed in accordance with international safety standards this manual contains information and warnings which must be fo
148. MOUNTS IN GEAR SPUR COVER AUDIO OSCILLATOR SUPPORT COVER AUDIO OSCILLATOR COVER BACK A OSCILLATOR SPACER BUSHING SCREW MACH 4 40 PAN HD POZI REC SST 300 SCREW MACH 6 32 RD HD SLT REC NYL NAT WASHER LK INTL T NO 4 115 IN ID 27 IN NUT HEX W LKWR 4 40 THD 094 THK 25 A F GLIDE NYLON EXTRACTOR PC BOARD BROWN PIN DRIVE 0 250 LG SUPPORT SUPPORT SUPPORT LOWER AUDIO OSCILLATOR LOWER AUDIO OSCILLATOR LOWER AUDIO OSCILLATOR INSULATOR VAR TRANSISTOR PNP TRANSISTOR NPN TRANSISTOR PNP INSULATOR XSTR TRANSISTOR NPN TRANSISTOR NPN TRANSISTOR NPN INSULATOR XSTR TRANSISTOR NPN TRANSISTOR PNP TRANSISTOR NPN TRANSISTOR PNP TRANSISTOR J F TRANSISTOR NPN RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 21 5M 196K 1 78 7K 21 5M 133K 1 AUDIO OSCILLATOR SI CHIP TO 18 PD 360MW SI PD 300MW FT 200MHZ SI CHIP TO 52 PD 360MW TO 5 075 THK SI TO 18 PD 360MW SI TO 39 PD 800MW SI TO 39 PD 800MW TO 5 075 THK SI TO 18 PD 360MW SI CHIP TO 52 PD 360MW SI PD 300MW FT 200MHZ SI CHIP PD 300MW ET N CHAN D MOCE SI SI PD 300MW FT 200MHZ 1 5W F TUBULAR 125W F TUBULAR 1 125W F TUBULAR 1 5W F TUBULAR 125W F TUBULAR MFR CODE 28480 80486 28480 28480 72136 72136 28480 73899 56289 28480 28480 56289 56289 56289 56289 56289 56289 56289 28480 28480 56289 56289 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 2
149. PD 1W INSULATOR XSTR TO 5 075 THK TRANSISTOR PNP SI CHIP TO 18 PD 360MW TRANSISTOR PNP SI CHIP TO 39 PD 1W INSULATOR XSTR TO 5 075 THK MFR CODE 26742 26742 28480 28480 28480 28480 28480 28480 28480 28480 71785 28480 28480 71785 28480 28480 71785 26742 26742 26742 71785 71785 28480 56289 28480 56289 56289 28480 28480 28480 28480 28480 28480 04713 28480 28480 28480 28480 28480 28480 28480 71400 28480 00000 28480 28480 28480 02735 28480 28480 28480 28480 28480 28480 REPLACEABLE PARTS MFR PART NUMBER 91 6915 0702 00 91 6915 0702 00 5060 0109 5060 9409 7120 4264 5020 8122 08640 60018 0403 0153 0403 0154 0403 0155 252 12 30 032 08640 60119 3140 0490 251 06 30 261 5040 0327 08640 60001 252 10 30 300 91 6915 0702 00 91 6915 0702 00 91 6915 0702 00 252 10 30 300 252 10 30 300 08640 60004 150D336X9010B2 0160 3534 30D906G016CC2 150D225X9020A2 0160 2055 1901 0040 1901 0025 1901 0025 1901 0040 1901 0040 SR1358 4 1901 0040 1901 0040 1901 0049 1901 0049 1901 0040 1901 0050 1990 0326 GMW 2A 4040 0752 OBD 1853 0020 1854 0232 1200 0173 2N3528 1854 0003 1853 0027 1200 0173 1853 0050 1853 0027 1200 0173 MODEL 8640B OPTION 004 REFERENCE DESIGNATION A18Q8 1809 18010 18011 18012 18 1 A18R2 A18R3 A18R4 A18R5 A18R6 A18R7
150. Q4 becomes more positive and Q4 more heavily biases the Hall generators The drive transistors turn on harder and rotor speed increases TROUBLESHOOTING It is assumed that the light emitting diode is unlit or that ripple noise or voltage from the 5 2V power supply is suspect or that the fan is operating erratically or not at all Troubleshoot by using the test equipment listed below performing the initial test conditions and following the procedures outlined in the text and the table Test Equipment Digital HP 3480D 3484A Oscilloscope 2 HP 180A 1801A 1820C SERVICE SHEET 23 Cont d Initial Test Conditions Top cover removed see Service Sheet G for removal procedure Use extender board to extend desired assembly set instrument LINE power switch to OFF while removing or inserting circuit boards Initial Control Settings Regulator Circuits A18 The first step in solving a power supply problem is to ensure that the problem is caused by the power supply Minimum load resistances are given below for the supply However depending upon the ohmmeter and resistance range used measured resistance can vary from a few ohms to several kilohms So unless the load is actually shorted to ground measuring load resistance doesn t isolate the problem Another way to isolate a power supply problem is to disconnect the supply from the load and check the supply voltage The quickest way to d
151. R21 ed aa 12 1V Qu Ae Hs OOF gt a n R25 look TEES uud C5 cu 632 110 2 6 0 22 epa Jii ie R28 8250 R29 6810 P O Figure 8 69 Counter Phase Lock Circuits Schematic Diagram P 0 Change 16 CHANGE 17 Page 6 29 Table 6 3 Change A14 to 0960 0443 LINE MODULE WITH FILTER BLACK NOTE For instruments with serial number prefixes below 1607A the recommended replacement for the 14 LINE MODULE is 0960 0443 Service Sheet 22 Schematic Change the part number for A14 to 0960 0443 1 60 Model 8640B Option 004 Service SECTION VIII SERVICE 8 1 INTRODUCTION 8 2 This section contains instructions for trouble shooting and repairing the Hewlett Packard Model 8640B Option 004 Signal Generator 8 3 principles of operation and troubleshooting information are located opposite the schematics on the foldout Service Sheets The last two foldouts in this manual have top and bottom internal views of the instrument showing the locations of the major assemblies and some of the chassis parts Also included are top and bottom internal views with the covers removed from the castings these views show the locations of the sub assemblies the adjustments and most of the instrument s test points The last foldout also shows a rear panel view of the instrument 8 4 The rest of this section has general service information that shou
152. Range Switch Assembly Component Locations Figure Page 8 26 A5 FM Amplifier Assembly Component Locations 8 27 FM Amplifiers Diasran 18 29 8 28 P O A7 FM Shaping Assembly Component Locations 8 31 8 29 FM Shaping Circuits and Phase ck bsp Filter Schematic Diagram J 8 31 8 30 P O Annunciator Assembly Component Locations A9 Peak Deviation and Range Switch Assembly Component Locations 8 32 8 32 P O A7 FM Shaping Assembly Component Locations 8 33 Over Deviation Detector and Meter Control Circuits Schematic Diagram 8 33 8 34 Fixed Frequency Modulation Oscillator Component Locations 8 35 8 35 Fixed Frequency Modulation Oscillator Schematic Diagram 8 36 Variable Frequency Modulation Oscillator Assembly Option 001 Component Locations 8 37 8 37 Variable Frequency Modulation Oscillator Option 001 Schematic Diagram 8 37 8 38 Action of RANGE Switch 8 38 8 39 A10A1 RF Filter Assembly Component Locations 8 40 IRF Filters Schemat N Logic Diagram of the Filter Divider Assembly 8 40 8 42 A10A2 RF Divider Assembly Componer Locations L 8 41 Dividers Schematic rece Modulator Assembly i Locations 8 43 8 45 A26A4 AGC Amplifier Assembly Component Locations 8 46 AGC Amplifiers and Amplitude Modulator Schematic Diagram 8 47 26 1 Pow
153. SI CHIP INSULATOR XSTR TO 5 075 THK TRANSISTOR NPN 2N3738 SI PD 20W PRESS IN NUT 6 32 062 LG 062 HGT HEAT DISSIPATOR SGL TO 49 PKG SCREW MACH 6 32 PAN HD PDZI REC SST 300 NUT HEX DBL CHAM 6 32 THD 094 THK 25 WASHER LK HLCL NO 6 141 IN ID 269 IN WASHER LK INTL T NO 6 141 IN ID 288 RESISTOR 46 4K 1 125W F TUBULAR RESISTOR 31 OHM 1 125W F TUBULAR RESISTOR 121 OHM 1 125W F TUBULAR RESISTOR 6 19K 1 125W F TUBULAR RESISTOR 1 33K 1 125W F TUBULAR RESISTOR 261 OHM 1 125W F TUBULAR RESISTOR 3 16K 1 5W F TUBULAR RESISTOR VAR TRMR 10 OHM 20 C SIDE ADJ RESISTOR 2 61K 1 125W F TUBULAR RESISTOR 1 33K 1 125W F TUBULAR RESISTOR 261 OHM 1 125W F TUBULAR RESISTOR 6 19K 1 125W F TUBULAR RESISTOR 31 6 OHM 1 125W F TUBULAR RESISTOR 121 OHM 1 125W F TUBULAR RESISTOR 46 4K 1 125W F TUBULAR RESISTOR 100 OHM 1 125W F TUBULAR RESISTOR 383 OHM 1 125W F TUBULAR RESISTOR 261 OHM 1 125W F TUBULAR RESISTOR 100 OHM 1 125W F TUBULAR RESISTOR 10 OHM 1 125W F TUBULAR NOT ASSIGNED RESISTOR 21 5 OHM 125W F TUBULAR RESISTOR VAR TRMR 1 10 C SIDE ADJ RESISTOR 1K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 10 OHM 1 125W F TUBULAR RESISTOR 8 25K 1 125W F TUBULAR RESISTOR 7 5K 1 125W F F TUBULAR RESISTOR 23 7K 1 125W F TUBULAR RESISTOR 11K 1 125W F TUUBLAR MODEL 8640B OPTION 004 MFR CODE 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 00000 284
154. SWITCH ASSEMBLY 08640 60179 _ _ P O A9A2 INTERCONNECT ASSEMBLY P O 1 1 DEV BAND SWITCH BD ASSY PIO 2 1 SEE NOTE 1 PIOPl J2 PIO W2 CODE 5 L P O S21 64 128 MHz 128 256 MHz 512 1024 MHz 1 t 1 1 1 1 D 1 t 1 i 1 1 1 1 P O_Figure 8 64 Counter Time Base Schematic Diagmm P O Change 7 7 50 Model 8640B Option 004 08640 90073 CHANGE 7 Cont d 978 JUMPERS TO BOARD Mots Model 8640B Option 004 08640 90073 CHANGE 7 Cont d A9AI Switch Assembly Legend Item Reference Item Reference Number Designator Number Designator A9AIMP31 A9AIMP3 5 A9A1MP30 A9AIMP6 9 28 9 7 8 9 22 A9AIMP41 A9AIMP21 A9AIMP40 9 23 A9A1MP39 A9A1MP24 A9AIMP38 9 1 1 A9AIMP37 A9A1A2 A9AIMP36 A9AIRI A9ATIWI 9 1 25 9 1 35 A9A 1MP28 Not Assigned 9 2 A9A1MP34 A9AIMP13 A9A1MP26 Not Assigned A9A1MP33 9 0 11 9 7 A9AIMP9 A9A1MP32 A9A1MP27 A9AIMP18 20 9 4 16 A9AIMPI 2 NO ta A W A9 Assembly Removal Procedure 1 2 Set PEAK DEVIATION and RANGE switches four positions ccw from full cw Place instrument upside down and remove bottom cover see Service Sheet G Disconnect gray coaxial cable A9A1W1 from 7 Shape
155. SWITCH ASSY AUDIO OSCILLATOR 28480 SWITCH ROTARY 28480 REPLACEABLE PARTS MFR PART NUMBER C4 1 8 TO 2152 F C4 1 8 TO 2153 F MF7C1 2 TO 2404 F 08640 60108 3100 3081 MODEL 8640B OPTION 004 REPLACEABLE PARTS TABLE 6 3 REPLACEABLE PARTS REFERENCE HP PART QTY DESCRIPTION MFR MFR PART NUMBER DESIGNATION NUMBER CODE Al2 08640 601901 RECTIFIER ASSY 28480 08640 60190 12 1 0160 0168 5 CAPACITOR FXD 1UF 10 200WVDC POLYE 56289 292P10492 A12C2 0160 0168 CAPACITOR FXD 1UF 10 200WVDC POLYE 56289 292P10492 A12C3 0160 0168 CAPACITOR FXD 1UF 10 200WVDC POLYE 56289 292P10492 A12C4 0160 0168 CAPACITOR FXD 1UF 10 200WVDC POLYE 56289 292P10492 A12C5 0160 0168 CAPACITOR FXD 1UF 10 200WVDC POLYE 56289 292P10492 12 1 1901 0418 20 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 A12CR2 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 A12CR3 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 12 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 A12CR5 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 Al12CR6 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 Al12CR7 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 A12CR8 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 A12CR9 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 A12CR10 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 12 11 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 Al12CR12 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 1
156. Shield No Spring Shield No Spring Shield No Cam Shaft Cam Shaft Follower D F Top Cover Casting D F Center Casting D F Bottom Cover Casting Bushing Cam Cover Cam Follower Slider Clamp Filter Switch Assembly Riser Board RF Divider Assembly Lockwasher Machine Screw Machine Screw Machine Screw Machine Screw Clamp Support Machine Screw Setscrew Lockwasher Hex Nut Machine Screw Machine Screw Blind Dome Rivet Slider Switch Service Figure 8 88 AIO Divider Filter Assembly Illustrated Parts Breakdown 8 79 Service SERVICE SHEET F A26 Assembly Disassembly Procedure A26A2 A26A4 and A26A8 Access 1 Place instrument right side up and remove top 3 cover see Service Sheet G Remove four pan head screws with lock washers that secure casting top cover to casting Lift cover from casting To service either A26A2 A26A4 or A26A8 gently lift board s extractors and reinstall it on extender board Reassemble by reversing procedures in steps one through four A26A1 and A26A3 Access 1 A10 Assembly Removal and Disassembly SERVICE SHEET E Place instrument upside down and remove bottom cover see Service Sheet G CAUTION While working with and around the semi rigid coaxial cables in the generator do not bend the cables more than necessary Do not torque the RF connectors to more than 2 inch pounds Remove ten pan head screws with lock washers that secure cas
157. Switch Modification Serial Number Prefixes 1406A and Below 7 31 If the line fuse blows as the instrument is switched off the line switch and line power assembly wiring W16 should be modified as explained below The fuse blows because of a momentary short on the primary input that can occur on a switch terminal used in wiring the pilot lamp The modification is simple and requires no special tools 7 32 Modify the switch as follows a Remove the power line cord b Remove instrument bottom cover and side cover nearest line power assembly c Remove nut that secures line switch to front panel and lift line switch free of instrument d Slip insulation tubing off line switch to expose wiring t Remove white green gray 958 wire from switch and clip off near cable sleeve This wire will no longer be used f Unsolder resistor lead from terminal where the white green gray 958 wire was pre viously attached and solder it to the terminal where the white red gray 928 wire is attached Switch wiring should now appear as i Slip insulation tubing back over switch and install switch into front panel h Remove white green gray 958 wire from terminal C of line power assembly and clip off near cable sleeve i Unsolder white yellow gray 948 wire from terminal E and solder it to terminal D where black green 05 wire is also attached 7 17 Manual Changes Insert power cord and check instrument for proper lin
158. TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL STDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD W F TUBULAR W F TUBULAR 05W F TUBULAR 05W F TUBULAR 05W F TUBULAR 5W F TUBULAR 125W F TUBULAR 125W F TUBULAR 5W F TUBULAR 125W F TUBULAR 5W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 05W F TUBULAR W F TUBULAR 05W F TUBULAR 05W F TUBULAR 05 TUBULAR 05W F TUBULAR W F TUBULAR PW TUBULAR 05 TUBULAR T IC DGTL SN74 74 N FLIP FLOP IC DGTL SN74 00 N GATE IC DGTL SN74 00 N GATE IC DGTL SN74 N INVERTER IC DGTL SN74 N FLIP FLOP IC DGTL SN74 02 N GATE IC DGTL LATCH IC DGTL LATCH IC DGTL LATCH IC DGTL LATCH IC DGTL LATCH IC DGTL LATCH IC DGTL SN74 08 N GATE IV FHYL MC 3003P GATE IC DGTL SN74 00 N GATE IC DGTL SN74 00 N GATE IC DGTL SN74 08 N GATE IC DGTL SN74 08 N GATE OC DGTL SN74 192 N COUNTER IC DGTL SN74 192 N COUNTER IC DGTL SN74 192 N COUNTER IC DGLT SN74 192 N COUNTER IC DGTL SN74 192 N COUNTER IC DGTL SN74 192 N COUNTER IC DGTL SN74 02 N GATE IC DGTL SN74 74 N FLIP FLOP IC DGTL MC 3003P GATE IC DGTL SN74 192 N COUNTER IC LIN AMPLIFIER DIODE ZNR 4 22V 5 DIODE ZNR 12 1V 5 TIME BASE ASSY CAPACITOR FXD 1UF CAPACITOR FXD 1UF CAPACITOR FXD 1UF CAPACITOR FXD 1UF CAPACITOR FXD 1UF DO 7 PD 4W TC DO 7 PD 4W 10 100MVDC CER 10 100 WVDC CER 10 100WVDC CER 10 100WVDC CER
159. TP6 voltage should re main at 17V TP6 voltage should de crease within a few seconds to 5V and U26A pin 6 Q should be low U29B pin 7 should be 20V Ground U14A pin 1 TP6 should remain at clears U26 V Set EXPAND to X10 Same results as steps a Repeat steps a throughe through e Ground U14 A pin 1 clears U26 Ground U26 A pin 3 T Initial conditions and settings Then set COUNTER MODE Source to INT and LOCK to ON Turn FREQUENCY TUNE control Repeat above except turn FREQUENCY TUNE control ccw USD pin 11 error signal is 5V high Same as above Set COUNTER MODE LOCK to Off Turn FRE QUENCY TUNE control Initial conditions and settings Gates and switches operate Then set COUNTER MODE correctly Source to INT and exercise EXPAND and LOCK switches U3D pin 11 error signal is OV dc low Check Q6 Q7 Q8 Q11 U26B U29 A and associated circuitry Same as above Same s above Same as above Same as above Check Q16 Q17 and associated circuitry Check Q2 Q15 U3 U16 and associated circuitry Same as above Same as above Check 51 Q1 U3 U4 016 and associated circuitry DOYVICE Model 8640B Option 004 A8 COUNTERILOCK ASSEMBLY 08640 60115 BOARD AS SEMBLY pau LIN AC MC CC CMM a ee ME REFERENCE DESIGNATIONS ABAS RISER o ASSEMBLY 0864
160. TUBULAR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 21 5K 1 125W 10K 1 125W F 3 16K 1 125W F TUBULAR 21 5k 1 125W F TUBULAR 464 OHM 1 125W F TUBULAR F TUBULAR TUBULAR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 5 62K 1 125F TUBULAR 10K 1 125W F TUBULAR 100 OHM 1 125W F TUBULAR 56 2 OHM 1 125W F TUBULAR 100 OHM 1 125W F TUBULAR RESISTOR 56 2 OHM 1 125W RESISTOR 56 2 OHM 1 125W RESISTOR 10 OHM 1 125W F TUBULAR RESISTOR 10 OHM 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR F TUBULAR F TUBULAR RESISTOR 14 7K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 261 OHM 1 125W F TUBULAR NOT ASSIGNED RESISTOR 10 OHM 1 125W F TUBULAR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 10 OHM 1 125W F TUBULAR 1K 1 125W F TUBULAR 196K 1 125W F TUBULAR 3 48K 1 125W F TUBULAR VAR TRMR 2KOHM 10 C RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 6 19K 1 3 16K 1 21 5K 1 2 37K 1 VAR TRMR 125W F TUBULAR 125W F E TUBULAR 125W TUBULAR 125W F TUBULAR 2KOHM 10 C RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 464 OHM 1 125W 5 62K 1 125W F 100 OHM 1 125W F TUBULAR 100 OHM 1 125W F TUBULAR 10K 1 125W F TUBULAR F TUBULAR TUBULAR RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 100 OHM 100 OHM 14 7K 1 2 61K 1 2 61K 1 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 5W F TUBULAR 5W F TUBULAR 1 1 RESISTO
161. The counter s time base is derived from a 5 MHz Reference Oscillator or an external reference and is divided by a divide by N counter the Time Base Decoder The division ratio is programmed by the frequency RANGE and EXPAND X10 and X100 switches The Up Down Counter drives the Storage Buffers which store the previous count while the counter is counting The Counter Display is driven from the Storage Buffers The Decimal Point Decoder decodes the decimal point information on the RANGE switch and the EXPAND switches and drives the display s decimal points The Overflow Detector senses when the count overflows the number of digits available on the display and turns on the OVERFLOW annunciator External Count Mode When the external count mode is selected the external signal enters the counter input in place of the RF oscillator s output When the 0 10 MHz mode is selected the 64 Divider is bypassed The EXT 0 550 MHz and 0 10 MHz switches also program the Time Base Decoder otherwise the counter s operation is identical to the internal count mode Phase Lock Mode When the LOCK switch is first depressed the counter continues to count up until the present count is terminated The count is then stored in the Storage Buffers and the counter enters the phase lock mode The count now proceeds with the count from the Storage Buffers being preset into the Up Down Counter The counter counts down to zero and then underflows i e a
162. Then clean it using a solution of warm water and soap or replace it using the part number listed in the table of replaceable parts in 3 12 The fan motor has factory lubricated sealed bearings and requires no periodic maintenance 3 13 Lamp Replacemerit Figure 3 explains how to replace the lamp located in the line power switch 3 14 Meter Zeroing To mechanically zero the front panel meter set LINE switch to OFF and place instrument in its normal operating position Turn adjustment screw cw until indicator indicates zero then turn adjustment slightly ccw to free mechanism from adjusting peg KNURLED NUT HP 0590 0923 lt 2 A HP 2140 0244 GUIDE PUSHBUTTON PLASTIC LENS HP 3101 0559 POWER LAMP REPLACEMENT Remove lens by pulling straight out Replace lamp replace lens align guide with notch in receptacle Push straight in Figure 3 1 Lamp Replacement 3 1 Operation Model 8640B Option 004 FRONT PANEL FEATURES 0 Meter Function interlocked buttons select one of three functions AM meter indicates percent of amplitude modulation FM meter indicates peak frequency devia tion LEVEL meter indicates RF output level in Vrms or dBm 50 PEAK DEVIATION set to 80 kHz a meter reading of 7 2 indicates that deviation is 72 kHz LEVEL VOLTS 0 3 and 0 10 scales are read in microvolt millivolts or volts de pending upon setting of the OUTPUT LEVEL 10 dB switch The 10
163. Vernier Assembly Machine Screw 2 Shaft Flexible Coupler RF Connector 10 dB Step Attenuator RF Connector Spacer 2 Spacer 2 Switch Wafer Lockwasher 2 A Figure 8 81 1 and 19 Output Level Assemblies Illustrated Parts Breakdown 8 71 SERVICE SHEET B A3 Removal Procedure 1 Place instrument upside down and remove bottom cover Service Sheet G CAUTION While working with and around the semi rigid coaxial cables in the generator do not bend the cables more than necessary Do not torque the R F connectors to more than 2 inch pounds 2 Set frequency to 230 MHz 3 Remove front panel FREQUENCY TUNE and FINE tune control knobs 4 rear of oscillator assembly disconnect coaxial connectors W 2 at A3A1J2 36 and W3 at A3A1J1 39 using wrench supplied 5 Remove two 8 32 nuts 45 that secure connector board assembly A3A4 to chassis Lift out connector board assembly from mating connector 6 Remove four 8 32 screws 20 securing oscillator to center plate of chassis 7 Exert firm pressure on assembly toward the front panel to compress the RFI gaskets and raise assembly about 1 4 inch to clear mounting studs Ease the assembly back and upwards to clear the tuning shafts This completes removal CAUTION Do not twist oscillator assembly while removing or inserting in chassis Doing so may loosen the front section of the oscillator causing excessive R F Ieakage and poor frequency calibration
164. Whenever it is likely that the protection i m e CIRCUITS DIVIDERS PN RF FILTERS OUTPUT ATTENUATORS 26 has been impaired the instrument must INT o ERNI AMPLIFIER be made inoperative and be secured oS I dms NOTE against any unintended operation Om i After repairs are complete see Table 5 2 E uud for the appropriate post repair tests AGC DETECTOR adjustments ol DEVIATION i INPUT OUTPUT 1 o o o SWITCH AGC REFERENCE mol i EU AMPLIFIER ST Lor a RE d b ae METER ATTENUATOR AGC SUMMING E gt 979998 mA AMPLIFIER f PHASE LOCK CIRCUITS _ LEVEL DEMODULATION o ST lt AMPLIFIER MODULATOR ROT er ATIENUATORS DETECTOR CIRCUITS DEMODULATION AMPLIFIER MODULATION DEMOD MODULATION MODULATION i 4 FREQUENCY fore pemon 4 AM t N 4 i pone ee e ouput 3 Figure 8 17 Simplified Block Diagram Figure 8 18 Overall Block Diagram 8 19 Overall Block Diagram SERVICE SHEET 1 Service SERVICE SHEET 2 PRINCIPLES OF OPERATION RF Oscillator Service Sheet 5 The full frequency range of the RF Oscillator is 230 to 550 MHz nominally 256 512 MHz The oscillator uses a single high frequency transistor in a foreshortened cavity Frequency is controlled by varying th
165. a mixer are used to down convert the test Signal Generator s RF output and noise to within the range of the spectrum analyzer A reference level is set on the analyzer with a 5 kHz signal the signal is changed to 1 MHz and removed from the analyzer with a filter and the broadband noise floor is measured SPECTRUM ANALYZER grim REFERENCE SIGNAL 10 dB STEP ATTENUATOR INPUT eese 9 e 9 EE 40 dB AMPLIFIER Figure 4 7 Single Sideband Broadband Noise Floor Test Setup EQUIPMENT Reference Signal Generator HP 8640A Mixer HP 10514A 15 kHz Low Pass Filter LPF e 7 pole 10dB Step Attenuator HP 355D 40 dB Amplifier HP 08640 60506 Spectrum Analyzer HP 141T 8552B 8556A PROCEDURE 1 Connect equipment as shown ih Figure 4 7 after setting test Signal Generator s controls as follows Meter Function LEVEL COUNTER MODE EXPAND l l LOCK Off Source FM OFF RAN GE 256 512MHz FREQUENCY TUNE 500000 MHz OUTPUT LEVEL Switches 7 dBm OUTPUT LEVEL Vernier CAL RF ON OFF LON 2 Set 10 dB step attenuator to 80 dB Set reference signal generator for a 500 005 MHz i e 5 kHz above the test generator s frequency C
166. a peak detector in a spectrum analyzer set to a zero frequency span scan width The ac and dc components are measured with a voltmeter at the detector output vertical output of the spectrum analyzer First the dc component is set to 282 8 mVdc plus a detector offset correction Then the ac component is measured and percent AM calculated at 1 2 the ac component read in mVrms Percent AM is then compared with the ac voltage of the demodulator output Because of the required measurement accuracy the accuracy of the spectrum analyzer s detector offset must be known to 1 mV The offset voltage is calculated by measuring the change in the detector output for a change in RF input and assuming a linear detector over the range of levels used TEST OSCILLATOR MODEL 86408 OPTION 004 CALIBRATED STEP ATTENUATOR SPECT oe ANALYZER VERTICAL pe Figure 4 22 Demodulated Output Accuracy Test Setup 4 65 Performance Tests PERFORMANCE TESTS 4 38 DEMODULATED OUTPUT ACCURACY TEST Cent d EQUIPMENT PROCEDURE Digital Voltmeter 3480D 3484A Option 043 Spectrum Analyzer HP 141T 8554B 8552B Test Oscillator HP 204D 10 dB Step Attenuator HP 355D Option H36 Model 640B Option 004 1 Connect the equipment as shown jn Figure 4 22 after setting the Signal Generator controls as follows Meter Function
167. accuracy of test Signal Generator s output using IF substitution by switching the OUTPUT LEVEL switch in 10 dB steps while switching the IF attenuator the calibrated 10 dB step attenuator The DVM should read 500 mVdc 0 5 dB 4 43 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 26 OUTPUT LEVEL ACCURACY TEST Complete Cent d IF Attenuator Test Generator DVM Readings dB OUTPUT LEVEL mVdc 500 set 529 6 529 6 529 6 529 6 12 Set the RF attenuator to O dB and the IF attenuator to 50 dB Use analyzer s display sensitivity controls to set the DVM to the reading noted at the 51 dBm step then continue The DVM should read 500 mVdc 1 dB IF Attenuator Test Generator DVM Readings dB OUTPUT LEVEL mVdc 50 51 dBm Set Level 40 61 dBm 445 6 561 0 13 Set the IF attenuator to 30 dB OUTPUT LEVEL to 71 dBm and then adjust the OUTPUT LEVEL 1 dB switch and vernier so that the test Signal Generator s panel meter reads 71 dBm then continue The DVM should read 500 mVdc 1 dB IF Attenuator Test Generator DVM Readings dB OUTPUT LEVEL mVdc 14 Set the IF attenuator to 0 dB OUTPUT LEVEL to 101 dBm and then adjust the OUTPUT LEVEL 1 dB switch and vernier so that the test generator s panel meter reads 101 dBm The DVM should read 500 mVdc 1 dB 445 6____________ 561 0 mVdc 15 Set the IF attenuator to 30 dB and use analyzer s display sensitivity controls to set the
168. actory Selected Components ze Post Repair Tests and Adjustments Power Supply Adjustments 5 26 Fixed Frequency Modulation Oscillator Adjustment 5 27 Variable Frequency Modulation Oscillator Adjustment Option 001 eter Adjustments ee 529 RF Detector Offset Aisen hoe eS p Level Vernier and Meter Adjustment 5 5 31 Preliminary AM Adjustments Accuracy Adjustment 5 33 Peak Deviation and Range Switch Adjustment Range Switch Adjustment 535 VT Pot A3R1 Adjustment 5 36 VT Voltage Adjustment 5 37 RF Oscillator End Stop Adfustment E 5 38 RF Oscillator Output Power Adjustment 5 39 RF Filter Adjustment EM 5 40 preliminary FM Adjustments BA FM Linearity Adjustment 5 22 FM Linearity Adjustment Alternate 5 0 Sensitivity Adjustment 5 44 Internal Reference Frequency Adjustment REPLACEABLE PARTS 6 L Introduction a 6 5 Abbreviations 6 7 Replaceable Parts List 6 11 Ordering Information 6 14 Spare Parts Kit Parts Bisikdowng ANUAL CHANGES Introduction 1 3 Manual Changes T6 Manual Change 7 7 Instrument Improvement Modifications 7 9 Improved FM Bandwidth 5 kHz Devia tion Range Serial Number Prefixes 1323A and 1327A n 1 oo LS t 4 09 D AAA 1 11 Section Page A10A2 RF Divider As
169. and RI 1 set the gain of the amplifier such that 100 AM produces 1 Vrms at DEMOD OUTPUT R15 provides adjustment to set the dc level at the output of U2 NOTE If the 20V supply is replaced or repaired perform the Preliminary AM Adjustments 5 31 AM Accuracy Adjustment 5 32 and Demodulated Output Accuracy performance test 4 38 TROUBLESHOOTING It is assumed that a problem has been isolated to the Demod ulation Amplifier as a result of using the troubleshooting block diagrams Troubleshoot by using the test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Oscilloscope HP 180A 1801A 1820C AM Preamplifier A13 A26A2 SERVICE SHEET 14 Service SERVICE SHEET 15 Cont d Initial Test Conditions To test A26A8 Demodulation Amplifier Assembly remove top cover see Service Sheet G for removal procedure remove A26 AM AGC and RF Ampli fier Assembly casting top cover and remove A26A8 and extend for service see Service Sheet F for procedure Initial Control Settings Meter Function 2 004 AM COUNTER MODE EXPAND Off Model 8640B Option 004 Initial Control Settings Cont d LOCK Off Source t o Riu athe etr sese INT MODULUATION 50 MODULATION FREQUENCY 1 kHz EM 5 2 7 20 aca quw OFF RANGE uet 64 128 M
170. associated resistors A8A3R10 and R17 are presented in Change 15 Service Sheet 20 Schematic Change the part number for A8LU U6 to 1990 0507 A8WU20 U24 U28 The recommended replacement for A8A7U20 U24 is 1820 1684 see Change 16 service Sheet 21 Schematic Change the pin designation diagram for A8A2Q6 to read from left to right G D S 7 23 Model 8640B Option 004 08640 90073 CHANGE 1 Page 6 2 Table 6 1 Change A8A2 as follows Part Number New Assy 08640 60189 Page 6 8 Table 6 3 Change A4CI to 0140 0191 CAPACITOR FXD 56 PF 5 300 WVDC MICA Change A4C3 and A4C4 to 0180 0116 CAPACITOR FXD 6 8 UF 10 35 VDC TA Delete A4CRI Change A4R3 to 0757 0449 RESISTOR 20K 1 0 125W F TUBULAR Change A4R5 to 0698 3243 RESISTOR 178K 1 0 125W TUBULAR Add A4R23 0757 0418 RESISTOR 619 OHM 1 0 125W F TUBULAR Add A4R24 0757 1094 RESISTOR 1 47K 1 0 125W F TUBULAR Continued 7 24 Model 8640B Option 004 08640 90073 CHANGE 1 Cont d Page 6 13 Table 6 3 Change A8A2 08640 60027 to A8A2 08640 60189 Page 6 23 Table 6 3 Change A10A2U5 to 1820 0143 IC MC 1027P J K FLIP FLOP Delete A10A2XA10A2U5 and A10A2XA10A2US age 6 28 Table 6 3 Add 12 6 0180 0197 CAPACITOR FXD 2 2 UF 10 20 VDC TA Add A12CR21 1901 0418 DIODE PWR RECT SI 400V MAX VRM 1 5A Add A12Q1 1884 0239 THYRISTOR SCR Add A12R1 and A12R2 0698 3447 RESISTOR 422 OHM 1 0 125W F TUBULAR Add A12VR1 190
171. at high frequencies can be reduced by changing All QI Refer to Service Sheet 9A The new transistor has a higher frequency response Distortion will improve mainly 7 16 Model 8640B Option 004 on the x3k band 60 to 600 kHz and only for the signal at the audio output jacks The change will not affect the signal into the AM and FM circuits 7 17 To make the modification order HP Part Number 1853 0050 and replace 1191 on 11 Variable Frequency Modulation Oscillator Per form the Internal Modulation Oscillator Test check voltage levels only and the Internal Mod ulation Oscillator Distortion Test Option 001 7 18 A12 Rectifier Assembly Input Crowbar Failures Serial Number Prefixes 1339A and Below 7 19 If the input crowbar SCR 1201 should fail do not replace it Instead remove 1201 Refer to Service Sheet 22 The A12 assembly is located directly behind the power transformer With the input crowbar disabled care must be taken to ensure that the Line Power Module is set to the correct line voltage Failure to do so could result in severe damage to major portions of the instrument Also check that the correct line fuse is in place 7 20 Reliability Improvements in AM and Pulse Circuits Serial Number Prefixes 1345A and Below 7 21 The reliability of some of the switching logic in the AM and pulse circuits especially at elevated temperatures can be improved by changing certain germanium diodes to hot ca
172. be adjusted on instruments or test measuring and diagnostic equipments used in precision measure ment Consists of comparisons of two instruments one of which is a certified standard of known accuracy to detect and adjust any discrepancy in the accuracy of the instru ment being compared g Install The act of emplacing seating or fixing into position an item part module component or assembly in a manner to allow the proper functioning of the equip ment or system h Replace The act of substituting a serviceable like type part subassembly or module component or assem bly for an unserviceable counterpart i Repair The application of maintenance services in spect test service adjust align calibrate replace or other maintenance actions welding winding riveting straightening facing remachining or resurfacing to restore serviceability to an item by corroding specific damage fault malfunction or failure in a part subassem bly module component or assembly end item or system j Overhaul That maintenance effort service action necessary to restore an item to a completely serviceable operational condition as prescribed by maintenance stand ards 1 DMWR in appropriate technical publications Overhaul is normally the highest degree of maintenance performed by the Army overhaul does not normally return an item to like new condition k Rebuild Consists of those services actions neces sary for t
173. be sharp and may cause personal injury if not handled with care 6 To gain access to the A8A1 RF Scaler Assem bly remove six pan head screws with lock washers that secure the cover shield Remove the cover shield and gasket A8 Removal NOTE The entire AS Assembly must be removed from the chassis to remove the ASAI and 8 Assemblies Do not attempt to replace components on the ASAI and 8 Assemblies ex cept A 8 103 without removing boards Turn instrument upside down and remove bottom cover see Service Sheet G CAUTION While working with and around the semi rigid coaxial cables in the generator do not bend the cables more than necessary Do not torque the R F connectors to more than 2 inch pounds Disconnect two semi rigid coaxial cables from bottom of A8 Assembly cable W2 at 8 1 2 and cable W14 at 1 1 Disconnect green flexible coaxial cable from bottom of A8 Assembly cable W15 at 1 Turn instrument right side up Remove A8 Assembly by removing four pan head screws with lockwashers that secure the A8 Assem bly to the chassis 8 1 Removal 10 Remove two pan head screws that secure LT A8A1U3 remove two lockwashers two wash ers and two nylon bushings Remove A8A1U3 and two mica washers On bottom of A8 Assembly casting under A8A1 Assembly remove hex nut and lock Model 8640B Option 004 SERVICE SHEET C Cont d washer Remove two hex nuts
174. by activating either the CU or CD input 8 67 The borrow BRW output is low whenever the Q outputs are at BCD zero 0000 The carry CRY output is low whenever the Q outputs are at BCD nine 1001 The master clear input CLR overrides all other input conditions and forces the Q outputs to BCD zero 8 68 Linear Integrated Circuits 8 69 Operational Amplifier Figure 8 15 shows a typical operational amplifier Circuit A is a non inverting buffer amplifier with a gain of 1 Circuit B is a non inverting amplifier with gain determined by the impedance of R1 and R2 Circuit C is an inverting amplifier with gain determined by R2 and Service Circuit D shows typical circuit connections and parameters It is assumed that the amplifier has high gain low output impedance and high input impedance 8 70 An operational amplifier can be character ized as an ideal voltage amplifier having low output impedance high input impedance and very high gain Also the output voltage is proportional to the difference in the voltages applied to the two input terminals In use the amplifier output drives the input voltage difference close to zero through a negative feedback path 8 71 When troubleshooting an operational ampli fier measure the voltages at the two inputs with no signal applied the difference between these volt ages should be less than 10 mV A difference voltage much greater than 10 mV indicates trouble in the amplif
175. carrier is the center spectrum line on the display A 50 dB null is when it drops 50 dB below its CW amplitude set in step 2 5 Set Signal Generators FREQUENCY TUNE to 16 MHz Adjust analyzer to center the carrier on the display Adjust LOW FM SENS adjustment A3A4R2 for at least 50 dB of carrier null 6 Set Signal Generators FREQUENCY TUNE to 32 MHz Adjust analyzer to center the carrier on the display Adjust HI FM SENS adjustment A3A4R4 for at least 50 dB of carrier null 7 Repeat steps 4 through 6 until carrier null is gt 50 dB at 16 24 and 32 MHz 8 Perform the FM Distortion Test 4 44 and FM Sensitivity y and Accuracy Tests 4 45 5 44 INTERNAL REFERENCE FREQUENCY ADJUSTMENT REFERENCE Service Sheet 19 DESCRIPTION An oscilloscope is used to display a Lissajous figure 2 1 to set the internal reference frequency The Lissajous figure is derived from the 10 MHz reference of a frequency counter and the Signal Generator s 5 MHz internal reference This procedure should be performed whenever the internal reference is found to be out of specification HORIZONTAL INPUT MODEL 86408 0 N 004 o0 FS Figure 5 15 Internal Reference Frequency Adjustment Test Setup TIME BASE OUTPUT NEL 10 MHz TIME BASE OUTPUT FREQUENCY COUNTER EQUIPMENT Frequency Counter HP 5327C Option H49 Oscilloscope HP 180A4 1801A 1820C 5 42 Model 8640B Option 004
176. conditions and control settings and following the procedures outlined in the table Test Equipment Digital Voltmeter 34800 3484 Model 8640B Option 004 Initial Test Conditions Bottom cover removed see Service Sheet 6 for removal procedure Extend A7 FM Shaping Assem bly on extender board Initial Control Settings COUNTER MODE LOCK OFF Positive and Negative Shaping A trouble in one of the shaping circuits will usually cause FM sensitivity distortion and meter accuracy to be out of specification and will also prevent FM linearity from being correct y adjusted The quick est way to troubleshoot the shaping circuits is to use the ohms function of the DVM to check the components Phase Lock Loop Filter A trouble in the loop filter will either prevent the generator from becoming phase locked or prevent frequency modulation at low modulation rates Trouble might also cause an increase in SSB noise or residual FM while phase locked A low voltage at 7 2 VARACTOR ANODE may indicate a faulty Phase Lock Loop Filter or Varactor Assem bly shown on Service Sheet 5 FM Shaping Circuits and Phase Lock Loop Filter Troubleshooting Component Test Conditions and or Circuit Control Settings POSITIVE and NEGATIVE SHAPING A7 Remove A7 Assembly from chassis Check com ponent resistances with DVM PHASE LOCK Initial conditions and LOOP FILTER settings Check voltages A7 shown on sch
177. dB amplifier s input impedance switch to 50 ohms Set reference signal generator for a 549 98 MHz CW signal at 13 dBm i e 20 kHz below test generator s frequency Fine adjust its frequency for a 20 kHz signal on analyzer s display Adjust analyzer s display reference level controls so that the 20 kHz signal is 4 3 dB below the top reference graticule line NOTE The correction factors for this measurement are as follows a The DSB to SSB transfer is 6 dB because the mixing process translates two correlated 1 kHz BW portions of the noise into the 1 kHz BW of the analyzer giving twice the effective noise voltage Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 21 SINGLE SIDEBAND PHASE NOISE TEST Cont d NOTE Cont d b 2 5 dB because noise is average detected after logging c 0 8 dB Effective noise BW is 1 2 x 3 dB BW which gives 0 8 dB 10 log actual 3 dB BW nominal dB BW Summing the correction factors gives 4 3 dB 1 O log actual 3 dB B W nominal 3 dB BW or approximately 4 3 dB 1 dB 5 Phase lock the generators by setting test generator s FM switch to DC and by tuning reference signal generator to 550 MHz for a difference frequency of O Hz Monitor phase lock on oscilloscope checking that mixer s output is 0 Vdc if it is not fine tune reference generator until it is 6 Set analyzer s display smoothing video filter to 10 Hz Set step attenuator to 0 dB The top ref
178. dB per division 4 Set analyzer s display reference level controls to display the detected sweep Slowly tune Signal Generator from 8 to 16 MHz while noting amplitude variations from 0 50 kHz on the display The variation should be lt 3 dB referenced to the level at 1 kHz 3 db 5 Set analyzer and Signal Generator as shown below At each RANGE switch setting repeat the procedure outlined in steps 2 through 4 except set analyzer for the frequency and percent AM shown The amplitude variation should in each case be lt 3 dB E Generator AM Frequency Amplitude RANGE Tracking Gen Level span Variation 0 to 35 KHz 0 to 30 KHz 0 to 20 kHz 0 to 15 KHz 0 to 12 5 kHz 4 57 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 35 AM DISTORTION TEST SPECIFICATION AM Distortion at 400 Hz and 1 kHz rates Frequency Bands 50 AM 50 90 AM DESCRIPTION A spectrum analyzer used to demodulate the AM is connected to RF OUT and percent AM is set a distortion analyzer is connected to the analyzer s vertical output and used to measure AM distortion MODEL 8640B OPTION 004 DISTORTION ANALYZER VERTICAL OUTPUT Figure 4 19 AM Distortion Test Setup EQUIPMENT Spectrum Analyzer HP 1417 8552 8554 Distortion Analyzer AA oe HP 333A PROCEDURE 1 Connect equipment as shown ih Figure 4 19 after setting Signal Generator s controls as fo
179. detector over the range of levels used TEST OSCILLATOR CALIBRATED STEP ATTENUATOR ooo lee VERTICAL OUTPUT ERI RF INPUT Figure 5 4 AM Accuracy Adjustment Test Setup EQUIPMENT Digital Voltmeter HP 3480D 3484A Option 043 Spectmm Analyzer HP 141T 8554B 8552B Test Oscillator x 1b 4 a Boe a AHP204D 10 dB Step Attenuator 2 5 HP 355D Option H36 PROCEDURE l Connect the equipment as shown in Figure 514 after setting the Signal Generator controls as follows Meter Function 4 de c9 do o o COUNTER MODE EXPAND LOCK Ue ER Um UR ue 3 ce ces ow Source m Of 2 5 19 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 32 AM ACCURACY ADJUSTMENT Cont d AM OFF MODULATION l l r l o Fully cw RANGE 2 4 MHz FREQUENCY 04 EE 3 MHz OUTPUT LEVEL Switches 43 dBm OUTPUT LEVEL Vernier CAL RF ON OFF LON Let the equipment warm up for two hours to minimize drift of the spectrum analyzer detector output Set calibrated step attenuator to 10 dB Set the spectrum analyzer center frequency to 3 MHz frequency span to 200 kHz per division resolution bandwidth to 300 kHz input attenuation to 20 dB and vertical scale to linear Set the frequency span to zero and tun
180. diagrams Troubleshoot by using the test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital HP 3480D 3484A 180A 1801A 1820C NOTE Use a 10 k resistor in series with the DVM probe tip to reduce spurious oscillations in the amplifier circuitry while making dc measurenents Initial Test Conditions Bottom cover removed see Service Sheet G for removal procedure Extend A5 FM Amplifier Assembly on extender board Remove A7 FM Shaping Assembly from chassis and disconnect cable A9W1 from 7 1 SERVICE SHEET 6 Cent d Initial Control Settings MODULATION FREQUENCY 400Hz EM nom le Baw eta E Boel Wow Xx av s PEAK DEVIATION 5 kHz PEAK DEVIATION Vernier Fully cw RANGE 0 5 1 MHz FREQUENCY TUNE Centered Four turns from stop RF ON OFF 222 555 FM Amplifier Troubleshooting Component Test Conditions and If Indication Buffer Initial conditions 2 Vp p at TP6 Check U1 and Amplifier A5 and settings Ad BUFFER OUT associated just PEAK DEVI circuitry ATION vernier for 2 Vp p at TP5 BUFFER IN Initial conditions FM Amplifier A5 and settings Ad just PEAK DEVI ATION vernier for Peak to peak voltages at TP3 INPUT and TP4 INPUT
181. gam to the detector 1 Vpk ac signal into the Positive Peak Detector will produce 1 Vde out However 0 977 Vde input to the Meter Drive Amplifier A4U1 produces full scale meter de flection In the LEVEL meter mode A26A4U1A Service Sheet 12 provides the proper input level to the peak detector In the AM mode a 1 Vpk ac signal would be reduced to 0 977 Vpk by voltage divider R9 R3 and correspond to full scale meter deflection In the FM mode the signal from the Peak Deviation Switch is not further SERVICE SHEET 17 Cont d attenuated so 1 Vpk would produce slightly greater than full scale meter deflection e g 5 12 MHz on the 5 scale Meter Drive Amplifier A4 Meter Drive Amplifier U1 scales the dc input voltage and drives meter M1 Transistor Q1 is a switch which operates in the inverted mode i e the emitter functions as a collector and the collector as an emitter When Q1 is OFF the amplifier gain is 10 when Q1 is ON the gain is 3 16 With an amplifier gain of 10 and an input of 977 mVde the meter which has a nominal 1mA full scale movement is adjusted to read full scale on the 0 10 scale by means of R19 Breakdown diode VR2 protects the meter from being overdriven or driven negative Autorange Comparator A4 Amplifier U2 functions as a Schmitt Trigger A reference voltage is established at pin 3 by voltage divider R3 and R4 Resistor R5 adds a small amount of hysteresis to the comparator Ripple at the
182. generators RF OUT to analyzer s input after setting Signal Generator s controls as follows Meter Function LEVEL COUNTER MODE EXPAND l r 1 Off LOCK Source INT FM OFF 256 512 MHz FREQUENCY TUNE 512 MHz OUTPUT LEVEL Switches 7 dBm OUTPUT LEVEL Vernier CAL RF ON OFF M We c che 5 ut ue e IAS do ues cR Vue 2 Set spectrum analyzer s input attenuation to 20 dB Adjust center frequency controls to center the 512 MHz signal on the display Adjust scale reference level controls to set the signal to the top O dB graticule line with the scale controls set to display 10 dB per division 3 Set generator s AM switch to PULSE and tune across band The signal on the analyzer s display should decrease and remain more than 40 dB below the reference 256 512 MHz 40 dB 4 Repeat steps 1 through 3 with the RANGE switch set to each of its other positions At each position the signal on the analyzer s display should decrease and remain more than 40 dB below the reference 128 356 MHz 40 dB 64 128 MHz 40 dB 32 64 MHz 40 dB 16 32 MHz 40 dB 8 16 MHz 40 dB 4 8 MHz 40 dB 2 4 MHz 40 dB 1 2 MHz 40 dB 0 5 1 MHz 40 dB 4 77 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 43 FM 3 dB BANDWIDTH TEST SPECIFICATION FM 3 dB Bandwidth Internal and e
183. gt 0 1 duty cycle DESCRIPTION A pulse generator is used to pulse modulate the Signal Generator The RF pulse output is detected and displayed and measured on an oscilloscope For RF outputs above 32 MHz a reference signal generator and a mixer are used to down convert the signal to within the range of the oscilloscope NOTE If a high frequency oscilloscope is available such as the 183C 1830A 1840A the above measurement may be made directly to frequencies slightly beyond the oscilloscope s nominal bandwidth Use the oscilloscope s 509 input See Table 4 1 Recommended Test Abridgements 4 73 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 41 PULSE MODULATION TEST Cont d REFERENCE SIGNAL GENERATOR 600000 MODEL 86408 OPTION 004 UNDER TEST xad AM RF OUT OSCILLOSCOPE PULSE GENERATOR 500 LOAD VEN pur EXTERNAL TRIGGER PULSE OUTPUTS oo 544 TRIGGER OUTPUT Figure 4 26 Pulse Modulation Test Setup EQUIPMENT Reference Signal Generator 8640A Mixer 10514A 50 Ohm Load HP 11593A Pulse Generator 8003A Oscilloscope HP 180A 1801A 1820C NOTE The reference signal generator should have a frequency range of 20 500 MHz with an output of 7 dBm PROCEDURE
184. initial settings before starting any section within the check Meter Function 4 Ge de T lt COUNTER MODE EXPAND Off LOCK ao a a ER wee ege OEE Source TIME BASE VERN AM De Af att NS en hed le 2 DORE AUDIO OUTPUT LEVEL 5 5 1v MODULATION Po do Seo lt amp ve we ge Fally CCW MODULATION FREQUENCY LKH FM v omo we 5 WD Wo Ee ue X 5 ORF PEAK DEVIATION 5S kHz PEAK DEVIATION Vernier Fully CCW 4 5 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 12 BASIC FUNCTIONAL CHECKS Cent d RANGE s s s 05 1 MHZ FREQUENCY TUNE Centered FINE TUNE a s s s s Centered OUTPUT LEVEL IOdB 910 dBm OUTPUT LEVEL 1 dB we din fac dA oap oce e Lie A a gt x OUTPUT LEVEL Vernier Ue hock hee amp CAL RF ON OFF 5 A ahi Sk a dels TA a mo LON atte xm ke exo Une wet 5 us Me es ahd ue TIME BASE rear panel NT 2 Preliminary Checks Refer to step 1 for initial control settings a Set LINE switch to OFF The panel meter should read exactly O when viewed directly from the front The air filter on the rear panel should be clean Set LINE switch to ON The lamp in the switch pushbutton should ligh
185. input overrides all other conditions and forces all outputs low 8 57 Binary Shift Register A five bit binary shift register is shown in Information of the data Dn inputs is transferred to the respective Qn outputs when the load LD input is high The load input is independent of the clock T input 8 58 If the load input is low a high going clock pulse shifts the output to the next adjacent output e g the output at Q now appears as the output of Qc Also the input state at the serial SER input appears at the Q output n A B C or Model 8640E Option 004 8 59 A low at the clear CLR input clears all outputs to a low independent of the clock The clear input overrides the load input BINARY LATCH ENPA co 545 55 909 0 BEFORE clock AFTER CLOCK INPUT D OUTPUT 0 Figure 8 10 Binary Latch 8 60 Decade Counters and Symbols 8 61 Basic Counter The basic decade counter or scaler or divider shown Figure 8 12 has logic states The active high outputs QA QB and QD increment by one BCD count each time the trigger TA or clock input goes from a high to a low The count sequence is also shown in the file The counter may be subdivided into a divide by two and a divide by five counter The two counters are connected in series the QA output connected to the TBD input to obtain a divide by ten counter The counter has two ANDed clear or reset to zero Ro inputs When
186. input pin 2 is reduced by R7 and C2 SERVICE SHEET 17 Cont d Logic Circuitry A4 The logie gates control the meter amplifier gain and scale lamps except for FM as outlined in Table 8 5 Whenever OUTPUT LEVEL switch 151 is in an odd range the ODD RANGE CODE line is grounded The ranges on the switch are num bered consecutively from 1 to 16 The highest output range is 16 which corresponds to a maximum output level of 3 16V For range 15 the maximum output level 15 1V for range 14 0 316V eic When the LEVEL mode is selected the 0 10 scale lamp is iurned on by Q2 when the range is odd and ihe input above the autorange reference or the 0 3 scale lamp is turned on by Q3 when the input is below the autorange reference When the range 1s even the lamp sequence is reversed the reversal is accomplished by Exclusive OR Invert function formed by gates U3B U3C and U4B In the AM meter mode the logic conditions are the same as for the LEVEL mode on an odd range In both the AM and LEVEL modes the Autorange Comparator and AND gate U4A tum on Q1 when the input to the Meter Drive Amplifier is below the autorange reference and turn off Q1 when above it Table 8 5 Meter Drive Amplifier Data Input Below Autorange Reference Input Above Autorange Reference Q1 Test Nom MUI Poi oint e Gain Q1 Either Either Odd Even NOTES No autoranging in FM mode
187. inside diameter intermediate frequency PEE impregnated EREE E inch E incandescent include s ree re input insulation All abbreviations in the parts list will be in upper case Replaceable Parts Table 6 2 Reference Designations and Abbreviations 1 of 2 m integrated circuit microcircuit HOSE e de electron tube voltage regulator breakdown diode cable transmission crystal unit piezo electric or quartz tuned cavity tuned circuit inductance capacitance light emitting diode low frequency linear taper used in ports list TERE linear LK WASH lock washer LO low local oscillator LOG logarithmic taper used in parts list log logrithm ic LPF low pass filter LV low voltage meter distance milliampere maximum T megohm meg 106 used in parts list MET FLM metal film MET OX metallic oxide MF medium frequency microfarad used in parts list manufacturer 2 milligram 2 megahertz 2 millihenry 2 mho minimum minute time minute plane 24 EAS MINAT m iniature mm millimeter 6 3 Replaceable Parts Model 8640B Option 004 Table 6 2 Reference Designations and Abbreviations 2 of 2 MOD MOM momentary MOS metal oxide semiconductor millisecond mounting meter indicating device modulator millivolt
188. label is provided with each instrument which contains ac values for particular AM factors to accuracy of ti 4 and 2 20 to 30 C The AC DC method for calculation of AM uses the following relationship AM 100 Vrms o accuracy 3 0 55 Vde 1 11 General Information Model 8640B Option 004 Table 1 1 Specifications 5 of 6 MODULATION CHARACTERISTICS Cont d Pulse Modulation Frequency Bands MHz 051 1 2 28 832 32512 Fise ard Fal Time ai 50 Hz to 50 Hz to ES Hz to 50 Hz to Pulse Repetition Rate 50 kHz 100 kHz ES kHz 500 kHz Pulse Width Minimum for level accuracy within 10 us 1 dB of CW 0 196 duty cycle Pulse ON OFF ratio gt 40 dB Peak Input Required 1 gt 0 5V 5 max sinewave or pulse return to zero Frequency Modulation Deviation Maximum allowable deviation equals 1 of FM Distortion at 400 Hz and 1 kHz rates See lowest frequency in each band as below 7 lt 1 for deviations up to 1 8 maximum allowable Frequency Band Maximum Peak lt 3 for maximum allowable deviation Deviation kHz External FM Sensitivity 1 volt peak yields maximum deviation indicated on PEAK DEVIATION switch with FM vernier at full cw position External FM Sensitivity Accuracy 6 from 15 to 35 C for FM excluding maximum peak deviation position Maximum peak deviation position 9 typically Indicated FM Accuracy 400 Hz and 1 kHz rates using internal mete
189. line in each case If necessary use generator s OUTPUT LEVEL 1 dB switch and vernier to reset panel meter to 1 dB Signal Generator Spectrum Anal yzer RF Level Set Log Reference Output Level 10 dB with Panel Level Control Meter dBm Display Amplitude dB 3 steps ccw Set Level 4 steps ccw 5 steps ccw 6 steps ccw 42 0 42 0 7 Set analyzer s vertical scale log reference level to 10 dBm and reset the 10 dB step attenuator to 30 dB with the vertical scale log reference vernier set the signal peak to the same level with respect to the horizontal center reference graticule line as the last measurement recorded on the preceding table NOTE If generator appears to be out of specification check accuracy of spectrum analyzer s vertical scale calibration 8 Step Signal Generators OUTPUT LEVEL 10 dB switch and analyzer s vertical scale log reference level control as shown in the followimg table Verify that the amplitude is within the specified tolerance If necessary w generator s OUTPUT LEVEL 1 dB switch and vernier to reset panel meter to 1 dB Signal Generator Spectrum Analyzer RF Level Set Log Reference Output Level 10 dB with Panel Level Control Display T ER Meter dBm 6 stepsCCW Bet level 7 steps ccw 8 steps ccw 9 steps ccw 10 steps ccw 9 Set step attenuator to 0 dB set spectrum analyzer s vertical scale log reference to 20 dBm Adjust vertical scale log reference vernier to give
190. list of recommended abridgments to the performance tests The abridg ments suggest rapid and relatively inexpensive ways to test the instrument while retaining those tests which are considered of prime importance in characterizing the generator Where alteration of a test is recommended a justification remark is also given Should individual needs make the justification invalid the test should be performed in its entirety For example the Incidental AM Test sometimes known as AM on FM has been omitted as being of secondary importance Should your application require characterization of this specification the test should be performed Performance Tests Model 8640B Option 004 Table 4 1 Recommended Test Abridgements 1 of 3 Frequency Range Test Check only 0 5 1 MHz range Frequency Accuracy and Fine Tune Test Omit steps 5 to 8 Frequency Stability vs Time and Restabilization Time Test Omit steps 5 to 7 Ranges obtained by binary division of 230 550 MHz RF oscillator All dividers operate on 0 5 1 MHz range Fine tune of secondary importance Restabilization time of secondary importance Frequency Stability vs Omit test Drift is small in a normal lab environment Temperature Test Frequency Stability vs Omit test Line Voltage Test Frequency Stability vs Omit test Load Level and Mode Test Frequency shifts are small in a normal lab environment RF oscillator well buffered from externa
191. low Current source Q7 charges capacitor C4 and Q12 discharges it Any phase difference from the phase detector results in a net charge or discharge i e an increase or decrease in voltage of C4 FET Q6 is a high impedance buffer amplifier which drives buffer Q11 Q11 drives the Phase Lock Loop Filter in the FM shaping circuits Service Sheet 2 In the EXPAND X10 mode transistors Q16 and 17 are switched Resistor capacitor networks R51 and C15 R52 and C16 now hold Q16 and Q17 on longer which in turn hold transistors Q8 and Q9 on longer to increase the duration of the pulse stretcher Capacitor C17 is also switched in to reduce ripple on C4 In the normal count mode U26A U26B are both set and cleared i e both Q and Q are high the current sources Q13 and Q14 are switched on to bias C4 at a nominal mid range voltage Error Detector A8A2 If the phase lock tune voltage from Q11 is too high or too low the limit of the lock range is approached so an error exists The error is sensed by transistors Q2 and Q15 The emitter of Q2 is held at 14 9V Q15 normally holds Q2 on If the base of Q15 is low the collector current is insufficient to hold resistor R30 and the base of Q2 at the 14 3V needed to keep Q2 on If the base of Q15 is high Q15 saturates and the collector voltage rises as the base rises When the collector voltage of Q15 exceeds 14 3V Q2 switches off and a low appears at the input of UIGA which represent
192. low It remains high until S1 is unlocked Transistor Q1 and diodes CR1 and CR2 form an OR gate with TIME BASE and S1 as inputs When the phase lock error exceeds a predetermined limit an error condition exists and a low appears at the input to NAND gate U16A and at the input to NAND gate U3D of the cross coupled pair formed by U3C and U3D The output of U3D goes high and turns on the Flash Oscillator Service Sheet 20 The output of is normally high but goes low when an error exists with USA high The output of NAND gate U16C is low when phase lock exists This is true when the output of USA is high i e 51 has been depressed and after that TIME BASE has gone low and the output of USC is high i e in addition no error exists The output of U16C is delayed by the resistor capacitor network of R38 and C7 and inverted by U4D which enables the Stall Counter and the main counter When an error occurs the output of U1LGC goes high and the counter reverts to the count mode until S1 has been released and then depressed NAND gate U16D prevents the error condition from reaching gate U3D when TP4 is grounded as an aid to troubleshooting Phase Lock Circuits A8A2 A phase error is sensed in the Null Phase Detector by detecting the difference in time of occurence of the 999 999 count of the counter see Service Sheet 20 and the TIME BASE signal D flip flops U26A and U26B and NAND gate U15C form the phase detector When phase locked
193. mVrms of reading in step 14 5 mVrms 16 Use MODULATION FREQUENCY range switch and vernier to tune oscillator across each range except 400 and 1000 Hz FIXED FREQ Monitor voltage level at A11TP3 the DVM should read within 10 mVms of level noted at 20 on vernier dial from 200 Hz to 100 kHz It should read within 20 mVrms of level noted at 20 on vernier dial from 20 Hz to 600 kHz 200 Hz tO 100kHz X 10 mVrms 20Hzto600kHz A A J 2X20mVrms 17 Set MODULATION FREQUENCY range switch to and vernier to 20 Connect DVM to AM OUTPUT jack through 600 ohm feedthrough Adjust AUDIO LEVEL adjustment 11 40 for 3 00 0 03 Vrms at the jack 2 97 3 03 Vrms 18 Set AM to OFF and FM to INT Connect DVM to FM OUTPUT jack through the 600 ohm feedthough The DVM should read 3 0 0 06 Vrms 19 Check that AUDIO OUTPUT LEVEL control indicates 3V when turned fully cw If it does not loosen its setscrews and adjust it so that it does then tighten setscrews Adjustments ADJUSTMENTS 5 28 METER ADJUSTMENTS REFERENCE Service Sheet 17 DESCRIPTION Model 8640B Option 004 The panel meter is mechanically zeroed The meter circuitry is then adjusted at zero and full scale EQUIPMENT Digital Voltmeter PROCEDURE HP 34800 3484 1 With LINE switch set to OFF place Signal Generator in its normal operating position e g if its normal operating position is tilted up with the tilt stand locked down place
194. metallic tuning tool NOTE The 256 512 MHz high band is the most difficult to adjust and usually takes many iterations Start with the adjustment capacitors oriented as in Figure 5 10 Stop band minimum loss should be gt 30 dB from 692 1000 MHz 5 31 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 39 RF FILTER ADJUSTMENT Cont d Table 5 3 RF Filter Check Signal Generator Sern BDETMMM Band Stop Band Analyzer Frequency Division 256 512 MHz Fully cw oe 100 MHz 550 MHz lt 3 dB 692 MHz gt 30 dB C81 84 Fully ccw 50 MHz 356 MHz lt 3 dB 460 MHz gt 30 dB L43 45 128 256 MHz Fully cw a 0 MHz 275 MHz lt 3 dB 346 MHz gt 30 dB L40 42 Fully ccw 0 MHz 128 MHz 3 dB 230 MHz gt 30 dB L37 39 54 128 MHz Fully cw 20 MHz 137 MHz lt 3 dB 173 MHz gt 30 dB L31 33 Fully ccw 10 MHz 89 MHz 3 dB 115 MHz gt 25 dB None 32 64 MHz Fully cw he 0 MHz 9 MHz lt 3 dB 86 5 MHz gt 25 dB None Fully ccw MHz 5 MHz lt 3 dB 58 MHz gt 25 dB None 8 16 MHz Fully cw High 16 32 MHz Fully cw oe 5 MHz 34 MHz lt 3 dB 43 2 MHz gt 20 dB None Fully ccw 2 MHz 22 MHz lt 3 dB 28 7 MHz gt 20 dB None 2 None 2 one i ab ii Fully Low MHz 0 MHz lt 3 dB 14 3 MHz gt 15 dB mw e 2 MHz os IMi MHz 22 2 MHz d 2 2 70 MHz MHz The 0 5 to 8 MHz bands have single filter for each band Ge
195. of the Meter Amplifier which is proportional to the detector output is amplified by the Meter Drive Amplifier On both AM and LEVEL one range of autoranging is provided The Autorange Compara tor senses the autorange condition and switches the gain of the Meter Drive Amplifier Logic circuits control gain switching of the Meter Drive Amplifier and turn on the proper scale lamps TROUBLESHOOTING It is assumed that a problem has been isolated to the AM AGC circuits and output amplifier as a 8 22 Model 8640B Option 004 result of using the overall block diagram Trouble shoot by using the test equipment and procedures specified below Test Equipment Digital Voltmeter HP 3480D 3484A Option 043 180 1801 1820 Power Meter and Sensor HP 435A 8482A Frequency Counter HP 5327C Initial Test Conditions Top and bottom covers removed see Service Sheet G Procedure Set the generator s controls as specified in the box at the right hand side of the diagram To check a voltage at a test point change the control setting as specified in the box associated with that test point check the voltage then reset the controls to the settings specified in the box at the right hand side The blocks are keyed by the numbers located in their lower right hand corners to the Service Sheets that have the circuit schematics NOTE The last two foldouts in this manual have to
196. of inverter U4B is normally high Counter U14 generates a low at the carry CRY output on the count of nine but the output of U4B remains high At the count of ten the carry output of U14 retums high output of U4B goes low until SERVICE SHEET 20 Cont d resistor R49 discharges capacitor C14 and the output returns to a high While U4B is low D flip flop clears Shortly after TIME BASE goes low the output of U16B goes high and toggles D flip flop USB If a low was present at the D input the Q output goes high tums on transistor 916 and lights the OVER FLOW lamp otherwise Q remains low When the TIME BASE goes high the Q output of U5A goes or remains high and remains so until an overflow carry is generated Counter Operation Phase Lock Count Down A8A2 When COUNTER MODE LOCK switch S1 is in ON the count just prior to the acquisition of phase lock is transferred to the storage buffers U7 through U12 and then the buffers are latched The decade counters U19 to U24 then count the input pulses counting down from the count stored in the buffers The count sequence is as follows The count proceeds down to zero then to 999 999 generating a borrow output in U19 The borrow causes the Stall Counter decade counter U28 with D flip flop U1B to be cleared from its normal nine count and the main counters to be preset from the Storage Buffers The input to the main counter is inhibited while the input to the Stall Counter
197. on a supply appears to be excessive check the reference either internal or external and its associated filter capacitor and ihe regulator amplifier Noise may either be of the broadband type ie white noise or it may consist of random jumps in level on the order of 1 mV i e popcorn noise SERVICE SHEET 22 Cont d Regulator Circuits A20 and 22 The first step in solving a power supply problem is to ensure that the problem is caused by the power supply Minimum load resistances are given in the table for each supply However depending upon the ohmmeter and resistance range used measured resistance can vary from a few ohms to several kilohms So unless the load is actually shorted to ground measuring load resistance doesn t always isolate the problem Another way to isolate a power supply problem is to disconnect the supply from the load and check the supply voltage The quickest way to do this is to unsolder and lift pins on the extender board However under some failure conditions the regulator integrated circuit can regulate correctly with the load removed from the power supply and yet cannot regulate correctly when the supply has its correct load To isolate a power supply problem to a specific cireuit use the data given in the table NOTE The voltmeter input must float i e both connections must be ungrounded when checking voltages with extender board pins open SERVICE SHEET 22 Cont d warnine Any a
198. power Poor contact on slide switch Changing bands does noi change output frequency even though the counter may indicate a change Divider Filter switch assembly The filters slide switches and the relays driven by the Schmitt Trigger circuits are shown and discussed on Service Sheet 10 Component or Circuit NOTE Check that the control inputs to the RF gates are correct before suspecting the gates themselves RF Divider Troubleshooting Test Conditions and Control Settings Normal Indication SCHMITT TRIG GER A10A2 Initial conditions and set tings 10V at TP1 If Indication is Abnormal Check slide switches Service Sheet 10 and pot Service Sheet 9 3 at TP2 OV 5V at TP4 Cheek U1 and associa ted circuitry Check U6 and ted circuitry Check U6 Q1 and associated circuitry Set FREQUENCY TUNE to 230 MHz 8 OV al TP1 V4 Check pot Service Sheet 5 ee a 5V at 2 Check U1 and associa ted circuitry 5V at TP3 Check U6 and assacia ted circuitry OV at TP4 Check U6 Q1 and RF DIVIDERS A10A2 8 40 Initial conditions and set tings then set RANGE to each position 10 dBm on panel meter associated circuitry Check appropriate divider and associated circuitry Check that following divider is off Service oervi
199. shown in Figure 8 83 Replace transistor cap 31 including the two RF I plugs 33 and 34 5 Connect power meter sensor HP 435A 8482A to the Divider Filter Buffer Amplifier output A3A1J1 41 Measure output power while tuning oscillator across band it should always be within 40 5 to 4 5 dBm If not perform adjustment irj paragraph 5 38 6 Connect power meter sensor to the Counter Buffer Amplifier Output A3A1J2 37 Measure output power while tuning oscillator across band it should always be within 12 to 2 dBm If not perform adjustment ig paragraph 5 38 1 and A9 Assemblies Removal and Disassembly SERVICE SHEET A Service PIN SIDE BOTTOM X 1 8 LONG pm m VIEWED FROM CUT PINS FLUSH WITH BOTTOM OF TRANSI STOR Figure 8 82 RF Oscillator Transistor Preparation Figure 8 83 RF Oscillator Transistor Orientation 8 72 Model 8640B Option 004 Service MP59 RFI Gasket MP60 Retaining Collar MP74 Setscrew 2 A3MP25 Fine Tune Shaft 26 Retaining Ring 4 Spur Gear A3 RF Oscillator Assembly Legend A3 RF Oscillator Assembly Legend 2 of 2 Reference re Reference ae 50 ASA1MP7 Machine Screws 2 A3A1MP8 1 2 Lockwashers 2 RF Divider Filter Buffer Amplifier Assembly Filter Capacitor Filter Capacitor 1 5 1 6 o 1o0 0 0 17 Setscrew 801 Transistor 1 Potentio
200. signal 6002 source impedance NOTE DEMOD OUTPUT is calibrated only when the OUTPUT LEVEL Vernier is in the CAL detent and not calibrated when the OUTPUT LEVEL 10 switch is set to 16 dBm An internal switch controls the level of the DEMOD OUTPUT signal Refer to Figure 3 3 FM selects frequency modulation and source OFF no FM INT FM by internal oscillator AC FM by external source through FM INPUT jack gt 20 Hz ac de lt 5 Vpk DC FM by external source through FM INPUT jack ac de lt 5 Vpk CAL used to calibrate external modulation input do not use when phase locked PEAK DEVIATION switch and concentric vernier vary FM frequency deviation as indicated on the meter Vernier range is from zero to the peak deviation selected by the switch INPUT OUTPUT 600 ohm input for exter nal FM nominally 1 Vpk 0 7071 Vrms required for full peak deviation selected by PEAK Figure 8 2 Front Panel Controls Indicators and Connectors 3 of 4 Model 8640B Option 004 Operation FRONT PANEL FEATURES DEVIATION switch never more than 5 Vpk Output for intemal oscillator whenever FM selector is set to INT 600 ohm source impedance level controlled by AUDIO OUTPUT LEVEL DEMOD CAL Label lists values of rms voltage by which percent AM can be set very accurately within 1 with a high impedance voltmeter at DEMOD OUTPUT Values provided by the factory apply when the internal
201. the gear on pot s shaft Set DVM to measure ohms and connect it between 936 and 938 wires on the pot Without changing position of FREQUENCY TUNE knob rotate compensation pot s shaft until DVM indicates between 0 and 9 ohms across the two wires Remove DVM tighten setscrews and set LINE to ON To adjust calibration voltage set FM switch to CAL set DVM to measure dc voltage and connect DVM to FM BUFFER IN test point ASTP5 Adjust FM CAL POT A13R3 for 1 000 0 001 Vdc at 5 5 To adjust amplifier offset voltages set FM switch to DC and set FREQUENCY TUNE to 300 MHz Connect DVM to BUFFER OUT test point ASTP6 and adjust BUFFER OFFSET adjustment ASR23 for 0 0 5 mVdc at ASTP6 Connect DVM to OUTPUT test point ASTP2 and adjust AMPLIFIER OFFSET adjustment A5R8 for 0 1 0 mVdc at ASTP2 Connect DVM to VARACTOR CATHODE test point A7TP3 and set PEAK DEVIATION switch as shown below The DVM should read as specified PEAK DEVIATION DVM Reading at A7TP3 lt 1 5 mVdc lt 1 0 mVdc 0 75 mVdc 0 50 mVdc 0 50 mVdc 0 50 mVdc 0 50 mVdc 0 50 mVdc 0 50 mVdc 0 50 mVdc AA AA A A lt A Reset PEAK DEVIATION switch to 2 56 MHz Turn PEAK DEVIATION vernier and FREQUENCY TUNE control through their ranges The voltage at A7TP3 should remain less than 1 5 mVdc 1 5 mVdc Set FM switch to OFF and note frequency displayed on generator s counter Set FM to DC the fre quency shoul
202. the INT counter mode the RF signal from the RF oscillator Frequency Counter Buffer Amplifier Service Sheet 5 passes through relay into Comparator US which converts the input signal to EECL compatible pulses In the EXT counter mode the external input couples into US through relay K2 and a diode network CR2 to CR5 which protects U5 from large voltages Dividers A8A1 EECL dividers U1 and U2 divide the frequency by 2 and 16 respectively U4 is an ECL divide by two In the INT or EXT 0 550 MHz counter modes the divider stages are enabled through the OR input of U1 and set S input of U4 The output of U3A is high U3D is low U3B inverts the Q output of U4 Note that for ECL and EECL ground is a logical high and an open and a negative is a logical low In the EXT 0 10 MHz counter mode the OR input of U1 is disabled high and the set S input of U4 is high therefore the output is low The output of U3A is low U3D inverts the RF input and U3B inverts the output from U3D with no frequency division Transistors Q1 and Q2 shift the EECL logic levels to ECL logic levels The output from the bypass gate U3D is ac coupled into transistor A8A3Q2 which converts the ECL logic levels to TTL logic levels The output of A8A3Q2 drives the counter circuits TROUBLESHOOTING It is assumed that a problem has been isolated to the counter RF scaler circuits as a result of using the troubleshooting block diagrams Troubleshoot by using th
203. the molding is in contact with a surface the loop antenna is one inch from the surface See Table 4 Recommended Test Abridgements 4 51 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 31 OUTPUT LEAKAGE TEST Cont d LOOP MODEL 86408 OPTION 004 ANTENNA 20 dB AMPLIFIER 0 1 400 MHz O 0 0 0 0 O 9e QuTeu 20 dB AMPLIFIER 400 1200 MHz Figure 4 15 Output Leakage Test Setup NOTE To avoid disturbing antenna s field and causing measurement error grasp antenna at the end that has the BNC connector EQUIPMENT One Inch Loop Antenna HP 08640 60501 20 dB Amplifier 0 5 400 MHz i i HP 8447A 20 dB Amplifier 400 1200 9 8447B Spectrum Analyzer o HP 71417 8552 8554 50 Ohm Load 7 required er s s s s HP 11593A PROCEDURE l 4 52 Connect equipment as shown in Figure 4 5 with Signal Generator connected to spectrum analyzer through 0 5 400 MHz amplifier after setting Signal Generator s controls as follows Meter Function 0 LEVEL COUNTER MODE EXPAND zb dioe mS owe 0 LOCK Off Source NT FM OFF RANGE we E RR URS 64 128 MHz FREQUENCY 100 MHz OUTPUT LEVEL Switches 107 dBm OUTPUT LEVEL Vernier RF ON OFF Set spectrum analyzer s resolution bandw
204. the noise when the OUTPUT LEVEL 1 dB switch is turned fully ccw 4 38 Model 8640B Option 004 PERFORMANCE TESTS 4 26 OUTPUT LEVEL ACCURACY TEST Complete SPECIFICATION Range a 10 dB step attenuator and a 1 dB step attenuator with vernier allow selection of output levels from 15 dBm to 142 dBm 1 3V to 0 018 into 502 Output Level dBm 15 to lo lo to 50 50 to 142 Total Accuracy as Indicated on 1 5 dB 2 0 dB 2 5 dB Level Meter DESCRIPTION RF output level accuracy above 10 dBm is measured with a power meter below 10 dBm cumulative error is measured against a lab calibrated step attenuator using an IF substitution technique The test Signal Generator s output is down converted to 3 MHz the IF using a mixer and a reference signal generator The 3 MHz IF is fed through the calibrated step attenuator to a spectrum analyzer A reference level is established on the analyzer and the step attenuator and the test generator s OUTPUT LEVEL 10 dB switch are stepped together Any amplitude variations are measured with a DVM connected to the analyzer s vertical output Performance Tests A spectrum analyzer tracking generator is connected with the two signal generators in a phase lock loop that prevents relative drift between the units See Table 4 1 Recommended Test Abridgements EQUIPMENT NOTE This procedure allows the output level accuracy to be verified down to 142 dBm Care must be
205. this test NOTE See Service Sheet H for component identification 4 63 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 37 PEAK INCIDENTAL PHASE MODULATION TEST Cont d 2 4 64 Meter Function AM COUNTER MODE EXPAND POSS Gey ste Ue Ra ds ee ICI o unen esu Source INT FM OFF RANGE maux devenu ROMERO Yt 256 512 MHz FREQUENCY TUNE 512 MHz OUTPUT LEVEL Switches 7 dBm OUTPUT LEVEL Vernier CAL RF ON OFF Set function generator for 1 kHz at approximately 500 mVrms and adjust Signal Generator s MODULATION control for 3096 AM as read on Signal Generator s panel meter Set function generator for 0 1 Hz Percent AM remains the same The low rate is necessary for the vector voltmeter s metering circuitry Set Signal Generator s AM switch to OFF Set vector voltmeter s frequency range to 300 600 MHz Zero the voltmeter s phase meter Set Signal Generator s AM switch to DC The vector voltmeter s phase meter should indicate less than 17 2 of deviation maximum 17 2 Set Signal Generator s RANGE to 64 128 MHz FREQUENCY TUNE to 128 MHz and repeat steps 3 through 5 except set vector voltmeter frequency range to 80 150 MHz The voltmeter s phase meter should indicate less than 8 6 of deviation maximum 8 6 D
206. with an external VOR ILS audio generator requiring DEMOD OUTPUT 0 1 Vrms reverse the procedure in step 2 to return the AC DC switch to DC 4 40 AM FLATNESS TEST SPECIFICATION Frequency Response 0 05 dB from 90 Hz to 150 Hz 108 to 118 MHz and 329 to 335 MHz 0 05 dB from 9 kHz to 11 kHz 108 to 118 MHz DESCRIPTION The Signal Generator is amplitude modulated and the modulation is demodulated by a peak detector in a spectrum analyzer set to a zero frequency span scan width The demodulated AM is measured with a digital voltmeter as the frequency of modulation is varied from 90 to 150 Hz and 9 to 11 KHz 4 71 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 40 AM FLATNESS TEST Cent d TEST OSCILLATOR MODEL 8640B OPTION 004 9 999 079 VERTICAL OUTPUT Figure 4 25 AM Flatness Test Setup EQUIPMENT Spectrum Analyzer 141T 8554B 8552B Test Oscillator HP 204D Digital Voltmeter HP 3480D 3484A Option 043 PROCEDURE 1 Connect equipment as shown in Figure 4 25 after setting Signal Generator s controls as follows Meter Function AM COUNTER MODE EXPAND Off LOCK Source s i a INT AM OFF MODULATION 2 5 5 2 r r Fully cew FM OFF RANGE mde 64 128 MHz FREQUENCY TUNE 5 5 10 59 5 50 113 MHz OUTPUT LEVE
207. 0 10 Preset Count af ULA Table 8 8 Count Modes of Counter ASABUTS U15 Data Inputs COUNTER Count Total MODE Condition Preset Count Count Division 0550MHz BAT 0 10 MHz Count 10 Preset Count SERVICE SHEET 19 Cont d Lock Decoder A8A3 The lock decoder further divides the time sase reference fre quency and adjusts the time base duty cycle for phase lock and non phase lock modes Counters 1711 and U10 each function as 10 counters In the uniocked mode LOCK is low as 15 the output of AND gate U4C which drives the reset to zero inputs at pin 2 of U11 and U10 The two counters in series count to 100 At the 100th count the Qp output of U10 goes low as does the output of buffer gate U5D the Q4 output of U12B goes high The output gate U5C is normally low being held low by resistor R12 on the inputs When the Q4 output of U12B goes high capacitor C24 ac couples the high into the reset to nine inputs of the counters and resets them to nine A short tune later the output of USC returns low The next pulse into the T 4 input of U11 clocks counters 1711 and 1 10 to zero and the output of U12B goes low The count sequence now repeats The result of the sequence is that the output of U12B is low for 100 counts of the input of U11 and high for one count dividing the frequency by 101 In the locked mode the LOCK line is high Counters U11 and U10 c
208. 0 35VDC TA SOLID CAPACITOR FXD 10 10 35VDC TA SOLI CAPACITOR FXD 10 10 35VDC TA SOLID CAPACITOR FXD NOT ASSIGNED 01UF 80 20 100WVDC CER MFR CODE 24546 16299 24546 19701 16299 24546 24546 16299 24546 16299 24546 16299 16299 16299 24546 16299 24546 16299 19701 16299 162999 24546 24546 16299 28480 28480 28480 28480 28480 28480 28480 28480 07263 01295 01295 04713 28480 28480 28480 95121 95121 95121 95121 28480 2K497 24226 24226 24546 16299 16299 24546 24546 28480 28480 00779 28480 56289 56289 56289 28480 REPLACEABLE PARTS MFR PART NUMBER C4 1 8 TO 1001 F C4 1 8 TO 196R F C4 1 8 TO 5111 F ET50X201 C4 1 8 TO 1962 F C4 1 8 TO 511R F C4 1 8 TO0 51R1 F C4 1 8 T0 4642 F C4 1 8 T0 5111 F C4 1 8 T0 4642 F 4 1 8 0 5111 4 1 8 0 2611 C4 1 8 T0 4642 F C4 1 8 T0 2371 F 4 1 8 0 5111 4 1 8 0 4221 4 1 8 0 5111 4 1 8 0 4222 4 1 8 0 1332 C4 1 8 T0 4640 F C4 1 8 TO 1961 F C4 1 8 T0 1002 F C4 1 8 T0 5111 F C4 1 8 TO 1961 F 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 710HM SN5400N SN74123N SZ 10939 158 08640 60016 0160 3094 0160 3094 TYPE QC TYPE QC TYPE QC TYPE QC 08640 60163 700177 1 15 152 15 471 C3 1 8 TO0 511R G C4 1 8 T0 2610 F C4 1 8 T0 2610 F C4 1 8 T0 511R F C4 1 8 T0 511R F 08640 80003
209. 0 Top Internal Views Option 001 Shown 8 91 Rear Panel Views 8 92 Bottom Internal Views Option 001 Shown 8 85 Model 8640B Option 004 WARNINGS SAFETY To avoid the possibility of injury or death the following precautions must be followed before the instrument is switched on a If this instrument is to be energized via an autotransformer for voltage reduction make sure that the common terminal is connected to the earthed pole of the power source b The power cable plug shall only be inserted into a socket outlet provided with a protective earth contact The protective action must not be negated by the use of an extension cord without a protective conductor grounding c Before switching on the instrument the protective earth terminal of the instrument must be connected to a protective conductor of the power cord This is accomplished by ensuring that the instrument s internal earth terminal is correctly connected to the instrument s chassis and that the power cord is wired correctly see Service Sheet 22 Whenever it is likely that the protection has been impaired the instrument must be made inoperative and be secured against any unintended operation Any interruption of the protective grounding conductor inside or outside the instrument or disconnection of the protective earth terminal is likely to make the instrument dangerous Inten tional interruption is prohibited HIGH VOLTAGE Any a
210. 0 0 040 0 040 0 040 0 748 749 750 ESSE 752 753 754 FSCM 28480 28480 28480 28480 28480 28480 28480 98291 98291 28480 28480 28480 28480 28480 28480 28480 28480 00779 71450 71744 07263 09353 15818 28480 28480 28480 28480 28480 28480 28480 28480 24226 NATIONAL STOCK NUMBER 5999 00 230 8834 6625 00 031 4796 5999 00 415 1213 5999 00 230 8835 5999 00 230 8832 5999 00 230 8836 5999 00 230 8837 5935 00 428 2944 5935 00 858 8794 6625 00 412 1204 6625 00 911 7214 6625 00 435 3153 5970 00 470 7622 5340 00 494 7440 5935 00 004 6303 5340 00 435 5340 6625 00 903 0348 5999 00 574 4399 5905 00 532 2926 6240 00 060 2941 5962 00 248 2636 5930 00 050 1198 5962 00 453 7739 6150 00 008 5075 6625 00 521 2801 6625 00 521 2802 6625 00 521 2803 6625 00 521 2809 6625 00 525 5256 6625 00 525 5263 6625 00 525 5311 5950 00 584 0107 PART NUMBER 9000 9100 9100 9100 9100 9100 9100 9100 2 9100 3 9140 0 9140 0 9140 0 9140 0 9140 0 9140 0 9140 0 9140 0 9140 0 612 615 618 620 622 641 232 512 036 098 12 14 37 42 44 78 80 974 307 PART NUMBER NATIONAL STOCK NUMBER TABLE 6 5 CROSS REFERENCE INDEX FSCM 73734 28480 28480 28480
211. 0 5910 00 883 6281 0180 0291 28480 5910 00 931 7055 0160 2307 28480 5910 00 406 9675 0180 0374 28480 5910 00 931 7050 0160 2357 28480 5910 00 451 3194 0180 1714 28480 5910 00 172 3138 0160 3046 28480 5910 00 138 5048 0180 1735 28480 5910 00 430 6016 0160 3094 28480 5910 00 847 9842 0180 1743 28480 5910 00 430 6017 0160 3219 28480 5910 00 430 5821 0180 1746 28480 5910 00 430 6036 0160 3456 28480 5910 01 014 2874 0180 2206 28480 5910 00 879 7313 0160 3457 28480 5910 00 832 9122 0180 2208 28480 5910 00 172 3140 0160 3458 28480 5910 01 005 9921 0180 2214 28480 5910 00 009 3200 0160 3459 28480 5910 00 894 6728 0180 2530 28480 5910 00 103 7651 0160 3872 28480 5910 01 027 9482 0340 0037 28480 5940 00 056 5560 0160 3876 28480 5910 00 572 5507 0340 0039 58480 5970 00 072 1625 0160 3878 28480 5910 00 348 2617 0360 0124 28480 5940 00 993 9338 0160 3879 28480 5910 00 477 8011 0360 1514 28480 5940 00 150 4513 0160 3934 28480 5910 00 500 9087 0490 1073 28480 5945 01 006 1410 0160 3936 28480 5910 00 500 9092 0490 1078 28480 5945 01 021 1345 0160 3937 28480 5910 00 500 9114 0490 1080 28480 5945 01 014 8137 0160 3938 28480 5910 00 488 3048 0510 0015 28480 5365 00 804 9672 PART NUMBER 0510 0052 0683 0475 0683 3355 0698 0024 0698 0082 0698 0083 0698 0084 0698 0085 0698 3 0698 3 0698 3 0698 3 0698 3 0698 3 0698 3 0698 3 0698 3 0698 3 0698 3 0698 3 0698 3 0698 3 32 36 50 51 52 53 5
212. 0 60028 NULL PHASE DETECTOR aa PULSE WIDTH STRETCHER a ee CURRENT SOURCE a BUFFER OUTPUT COUNTER LOAD IL CLT 15 1831 CR1 2 20 01 2 6 1 2 1 38 51 4 REFERENCE DESIGNATIONS WITHIN OUTLINED 51 ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN TP3 4 6 CLUDES ASSEMBLY NUMBER g RI OF ASSEMBLY Al 15 AIR DESIGNATIONS OF OTHER COMPONENTS 3 4 14 15 COMPLETE 5 SHOWN 116 26 29 VRL2 2Z0N 20V D NOTES 6 Tstt BACKDATING C yos AND 7 2 R25 n R27 MN 1854 ABA cig 0K 29 100K a TOP VIEW 4 5 8 LEN S Cd IK 1680 uF zh uF Pig mms ERROR DETECTOR summ 20V EXP 10 D 6 D 11 1 4 22 5 uw D ERROR ABA2U3 4 14 16 26 COUNTER MODE z 16 pi Ub 20 TOPVIEW EXPAND 2 n la 8 4 R33 1820 0054 SIA OFF a 14 7K um CRI rai 10K 7 S og i 19 1853 0020 i 16 ban mo du 14 8 ji HE 1960 ae 23 3 DELAYED LOCK iHi em 20 l oo00000 ia 090090 Jos R35 re na 1854 0071 5H KEY B R32 3 10K TIME BASE 20 TIME BASE 180 LOCK
213. 0 with the attached figure pig 5086 2089 Oe ue 320 Figure 7 5 ASAI RF Scaler Assembly Component Locations Backdating Change H 7 10 Model 8640B Option 004 Manual Changes MANUAL CHANGES CHANGE G Cont d Service Sheet 18 schematic Delete A8A1CR4 and CRS Service Sheet 22 schematic Change part number for A20Q4 to 1853 0038 NOTE See paragraph 7 25 for recommended instrument modification CHANGE 1 Page 6 3 Table 6 4 Change 1801 to 1826 0010 Page 6 31 Table 6 3 Change 2001 and U2 to 1826 0010 6 32 and 6 33 Table 6 8 Change A22 to 08640 60006 Change A22R6 to 0698 3154 RESISTOR FXD 4 22K 1 0 125W F TUBULAR Delete A22R28 Change A22U1 and U2 to 1826 0010 Delete A22VR6 Page 6 42 Table 6 3 Change W16 to 8120 1525 CABLE SHLD 6 COND 22 AWG Service Sheet 22 Principles of Operation Change the first sentence of 20V Regulator A22 as follows R5 R6 and R7 and is compared directly with the zener diode reference at pin 4 of U2 7 11 Manual Changes Model 8640B Option 004 MANUAL CHANGES CHANGE Cont d Service Sheet 22 component locations Replac _Figure 8 73 with the attached figure A22 Figure 7 6 A22 20V and 20V Regulator Assembly Component Locations Backdating Change I Service Sheet 22 schematic Change part number for A22 to 08640 60006 2 places Change part number for v
214. 00PF 1 100WVDC MICA 750PF 1 300WVDC MICA 500PF 1 300WVDC MICA 47PF 5 300WVDC MICA 80PF 2 300MVDC MICA 80PF 2 300MVDC MICA 51PF 5 300WVDC MICA 27PF 5 300WVDC MICA 51PF 5 300WVDC MICA 51PF 5 300WVDC MICA 300WVDC MICA 91PF 1 300WVDC MICA 00 1 300WVDC MICA 500PF 1 300WVDC MICA 480PF 1 300WVDC MCIA 340PF 1 100WVDC MICA 360PF 1 300WVDC MICA 250PF 1 100WVDC MICA 22PF 5 500MVDC CER 0 39PF 5 300WVDC MCIA 39PF 5 300WVDC MICA 24PF 5 500WVDC CER 0 13PF 5 500WVDC CER 0 24PF 5 500WVDC CER 0 24PF 5 500WVDC CER 0 16 5 500WVDC CER 0 10 5 500WVDC 0 18PF 5 500WDVC CER 0 18PF 5 500WVDC CER 0 5 500WVDC CER 0 TRMR CER 2 8PF TRMR CER 5 5 18P F TRMR CER 5 5 18PF TRMR CER 2 8PF 47UF 80 20 25WVDC CER MFR CODE 72136 72136 72136 72136 72136 72136 28480 28480 28480 28480 28480 72136 28480 28480 28480 28480 72136 72136 28480 28480 72136 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 72136 28480 28480 72136 72136 28480 28480 28480 28480 28480 72136 28480 28480 28480 28480 28480 28480 28480 28480 28480 72136 72136 72136 28480 28480 28480 28480 72136 72136 28480 28480 28480 28480 28480 28480 28480 28480 28480 73899 73899 73899 73899 28480 REPLACEABLE PARTS MFR PART NUMBER DM15F321F0300WV1C
215. 01 0698 3446 0698 3132 0757 0401 0757 0346 0698 3430 2100 3154 0757 0280 0757 0280 0757 0346 0757 0441 0757 0440 0698 3158 0757 0443 QTY 14 M 15 TABLE 6 3 REPLACEABLE PARTS DESCRIPTION DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE GEN PRP 100V 200MA DIODE SWITCHING 2NS 80V 200MA DIODE SWITCHING 2N2 80V 200MA DIODE SWITCHING 2NS 80V 200MA DIODE GEN PAP 100V 200MA RELAY REED 1 5A 200V CONT 4V COIL EXTRACTOR PC BOARD RED PIN DRIVE 0 250 LG EXTRACTOR P C BOARD WHITE PIN DRIVE 0 250 LG TRANSISTOR NPN DUAL 200 10MV VBE TRANSISTOR NPN DUAL 200 10MV V8E TRANSISTOR NPN SI TO 18 PD 360MW TRANSISTOR NPN SI TO 18 PD 360MW TRANSISTOR PNP SI CHIP TO 39 PD 1W HEAT DISSIPATOR SGL TO 5 PKG INSULATOR XSTR TO 5 075 THK TRANSISTOR PNP SI CHIP TO 39 PD 1W HEAT DISSIPATOR SGL TO 5 PKG INSULATOR XSTR TO 5 075 THK TRANSISTOR PNP SI CHIP TO 39 PD 1W INSULATOR XSTR TO 5 075 THK TRANSISTOR NPN 2N3053 SI PD 1W INSULATOR XSTR TO 5 075 THK HEAT DISSIPATOR SGL TO 5 PKG TRANSISTOR NPN SI TO 39 PD 700MW INSULATOR XSTR TO 5 075 THK TRANSISTOR NPN SI PD 20W PRESS IN NUT 6 23 062 LG 062 HGT HEAT DISSIPATOR SGL TO 49 PKG SCREW MACH 6 32 PAN HD POZI REC SST 300 NUT HEX DBL CHAM 6 32 THD 094 THK 25 WASHER LK HLCL NO 6 141 IN ID 269 IN WASHER LK INTL T NO 6 141 IN ID 288 TRANSISTOR PNP 2N2904A
216. 01 0025 A10A2CR3 1901 0025 10 2 4 1901 0025 10 2 5 1901 0025 10 2 1901 0025 10 2 7 1901 0025 10 2 8 1901 0025 10 2 9 1901 0025 10 211 2104212 A10A2L3 9100 1620 A10A2LA4 9140 0096 A10A2L5 9100 1612 A10A2L6 9140 0094 A10A2L7 9100 1615 A10A2L8 9140 0098 A10A2L9 9100 1618 A10A2L10 9140 0114 A10A2L11 9100 1620 A10A2L12 9100 1620 A10A2L13 9100 1628 A10A2L14 9100 1620 A10A2L15 9100 1620 A10A2L16 9100 1628 A10A201 1854 0071 A10A202 1853 0034 A10A203 1853 0034 A10A204 1853 0034 A10A205 1854 0345 10 2 1 0757 0394 A10A2R2 0757 0394 A10A2R3 0757 0394 A10A2RA 0757 0984 A10A2R5 0757 0438 A10A2R6 0698 7194 A10A2RT7 0698 7223 A10A2R8 0698 7223 A10A2R9 0757 0394 A10A2R10 0757 0984 A10A2R11 0757 0438 A10A2R12 0698 7194 A10A2R13 0698 7223 A10A2R14 0698 7223 A10A2R15 0757 0394 A10A2R16 0757 0438 A10A2R17 0757 0984 A10A2R18 0698 7194 A10A2R19 0698 7223 A10A2R20 0698 7223 A10A2R21 0757 0398 A10A2R22 0757 0984 A10A2R23 0757 0438 A10A2R24 0698 7224 A10A2R25 0698 7219 A10A2R26 0698 7190 A10A2R27 0698 7227 A10A2R28 0698 7227 A10A2R29 0698 3437 A10A2R30 0757 0399 QTY TABLE 6 3 REPLACEABLE PARTS DESCRIPTION CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 10 10 35VDC TA SOLID CAPACITOR FXD 10 10 35VDC TA SOLID CAPACITOR FXD 10 10 35VDC TA SOLID CAPACITOR FXD 10 10 35VDC TAOSOLID CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD
217. 02 Output Level 2100 mV in 500 One Inch Loop Antenna To ensure measurement accuracy no substitution HP 08640 60501 is possible Fabrication depends upon machining and assembling to very close tolerances 10 dB Step Attenuator Attenuation 0 120 dB in 10 dB steps HP 355D P A Range 0 45 550 MHz Attenuation 0 120 dB in 10 dB steps HP 355D P A Accuracy 0 02 0 015 dB 10 dB step Option H36 at 3 MHz Accuracy 1 5 dB 90 dB 0 3 dB to 120 dB below 1 kHz 3 dB Attenuator Accuracy 0 5 dB to 550 MHz HP 8491 Opt 003 10 dB Attenuator Accuracy 0 5 dB to 550 MHz HP 8491A Opt 010 20 dB Attenuator Accuracy 0 5 dB to 550 MHz HP 8491A Opt 020 Crystal Detector Range 0 45 550 MHz HP 8471A Low Level Sensitivity 70 35 mV uW v 2 HP 465A Calibrated Step Attenuator No internal dc return Crystal Detector Range 10 550 MHz Maximum Sensitivity at 15 17 dBm input With internal dc return P Performance A Adjustment T Troubleshooting 1 14 Model 8640B Option 004 General Information Table 1 2 Recommended Test Equipment 2 of 6 Critical Specifications Suggested Model Digital Voltmeter DC Accuracy 0 01 of reading 0 02 of 3480D 8484A range with Options AC True RMS Accuracy 0 1 of reading 042 043 Ohms Range to 1 Digital to Analog Accuracy 1 of full seale HP 581A Converter
218. 02 4 DIODE ZENER 15V VZ 1W MAX PD 04713 5211213 191 A22VR2 1902 3256 2 DIODE ZNR 23 7V 5 DO 7 PD 4W 04713 SZ 10939 290 A22VR3 1902 0761 2 DIODE ZENER 6 2V VZ 25W MAX PD 04713 1N821 A22VR4 1902 0202 DIODE ZENER 15V 2 1W MAX PC 04713 5211213 191 A22VR5 1902 3256 DIODE ZNR 23 7V 5 DO 7 PD 4W 04713 52 10939 290 A22VR6 1902 0761 DIODE ZENER 6 2V VZ 25W MAX PD 04713 1N821 A22XF1A 1251 2313 CONNECTOR 1 CONT SKT 04 DIA 00779 3 332070 5 A22XF1B 1251 2313 CONNECTOR 1 CONT SKT 04 DIA 00779 3 332070 5 A22XF2A 1251 2313 CONNECTOR 1 CONT SKT 04 DIA 00779 3 332070 5 A22XF2B 1251 2313 CONNECTOR 1 CONT SKT 04 DIA 00779 3 332070 5 A23 NOT ASSIGNED A24 08640 600071 SERIES REGULATOR SOCKET ASSY 28480 08640 60007 A24MP1 0361 0009 1 RIVET SEMITUBULAR OVAL HD 0 188 LG 00000 OBD A24MP2 0403 0152 1 GUIDE P C BOARD BLACK 28480 0403 0152 24 01 1200 0041 5 SOCKET ELEC XSTR 2 TO 3 PKG SLDR 00014 PTS 1 24 02 1200 0041 SOCKET ELEC XSTR 2 CONT TO 3 PKG SLDR 00014 PTS 1 24 03 1200 0041 SOCKET ELEC XSTR 2 TO 3 PKG SLDR 00014 PTS 1 A24XQ4 1200 0041 SOCKET ELEC XSTR 2 CONT TO 3 PKG SLDR 00014 PTS 1 A25 NOT ASSIGNED A26 08640 600581 AM CASTING ASSY 28480 08640 60058 26 1 0160 2049 CAPACITOR FXD 5000 80 20 500WVDC CER 28480 0160 2049 A26C2 0160 2049 CAPACITOR FXD 5000PF 80 20 500WVDC CER 28480 0160 2049 A26C3 0160 3219 3 CAPACITOR FXD 100PF 20 500WVDC CER 28480 0160 3219 A26C4 0160 3219 CAPACITOR FXD 100PF
219. 040 0392 A8MP21 5040 0393 A8MP22 5040 0394 A8MP23 5040 0395 A8MP24 2190 0368 A8MP25 2190 0019 A8MP26 2200 0147 A8MP27 2200 0107 A8MP28 2200 0151 A8MP29 2190 0005 A8MP 30 2950 0006 QTY 1 16 PRR RPP TABLE 6 3 REPLACEABLE PARTS DESCRIPTION RESISTOR 61 9 OHM 1 125W F TUBULAR RESISTOR 75 OHM 1 125W F TUBULAR RESISTOR 90 9 OHM 1 125W F TUBULAR RESISTOR 121 OHM 1 125W F TUBULAR RESISTOR 162 OHM 1 125W F TUBULAR RESISTOR 100 OMM 1 125W F TUBULAR NOT ASSIGNED NOT ASSIGNED NOT ASSIGNED RESISTOR 2 37K 1 125W F TUBULAR RESISTOR 1 1K 1 125W F TUBULAR RESISTOR 42 2K 1 125W F TUBULAR RESISTOR 42 2K 1 125W F TUBULAR RESISTOR 2 37K 1 125W F TUBULAR RESISTOR 750 OHM 1 125W F TUBULAR RESISTOR 8 25K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 10 OHM 1 125W F TUBULAR RESISTOR 511 OHM 1 125W F TUBULAR TERMINAL SLDR SUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD IC LIN AMPLIFIER IC DGTL COMPARATOR ANALOG IC DGTL SN74 05 N INVERTER DIODE ZNR 6 19V 5 DO 7 PD 4W DIODE ZNR 12 2V 5 DO 7 PD 4W COUNTER LOCK ASSY CAPACITOR FXD 5000PF 80 20 500WVDC CER CAPACITOR FXD 5000PF 80 20 500WCDV CER CAPACITOR FXC 5000PF 80 20 500WVDC CER CAPACITOR FXD 5000PF 80 20 500WVDC CER CAPACITOR FXD 1000PF 80 20 500WVDC CER CAPACITOR FXD 1000PF 80 20 500WVDC CER CAPACITOR FXD 5500
220. 060 0222 5660 8737 5060 0767 1490 0030 5000 0051 5060 8740 5009 6711 Table 6 3 Replaceable Parts FIGURE 6 1 CABINET PARTS FRAME ASSY 5 X 16 FRONT CASTING 5H FM PANEL REAR COVER 5 IDE PERFORATED COVER FRONT S IDE COVE TOP COVER BOTTOM HANDLE ASSY 5H SIDE HANDLE RETAINER FOOT ASSY FM WIREFORM TRIM STRIP KIT RACK MOUNT 5H MINT GRAY COVER FRONT SIDE MINT GRAY See introduction to this section for ordering information Replaceable Parts Mfr Part Number 08640 20075 08640 20231 08640 00026 5000 8705 5000 8707 08640 00003 08640 00004 5060 0222 5060 8737 5060 0767 1490 0030 5000 0051 5060 8740 5000 8711 Replaceable Parts Model 8640B Option 004 Table 6 3 Replaceable Parts Reference HP Part ipti Mfr Mfr Part Number FIGURE 6 2 TYPE N CONNECTOR 1250 0914 CONNECTOR RF APC N FEM 90 131 150 1250 0915 CONTACT RF CONNECTOR FEMALE CENTER 131 149 2190 C104 WASHER LK INTL T 4 439 IN 10 547 IN 00 1922 04 2950 0132 NUT HE CHAM 7 16 28 THD a 094 THK T6500NP 5040 0306 INSULATOR 5040 0306 08555 20093 CENTER CONDUCTOR 08555 20093 08555 20094 BODY BULKHEAD 08555 20094 08751 2027 INSULATOR 08761 2027 See introduction to this section for ordering information Model 8640B Option 004 Replaceable Parts Table 6 4 Code List of Manufacturers Manufacturer Name NECHM ANY SUPPLIER OF U S A ARIZONA COIL INC ILLUMINATEO PRODUCTS I NC BEE LINE SPE
221. 071 28480 1853 0020 28480 1853 0020 28480 1854 0071 16299 C4 1 8 TO 196R F 24546 C4 1 8 TO 5111 F 24546 C3 1 8 TO 5111 G 24546 C3 1 8 TO 5111 G 24546 C3 1 8 TO 1331 G 24546 C3 1 8 TO 1331 G 24546 C3 1 8 TO 2611 G 24546 C3 1 8 TO 2611 G 24546 C3 1 8 TO 5112 G 24546 C3 1 8 TO 5112 G 01121 CB8245 01121 CB8245 24546 C3 1 8 TO 1962 G 24546 C3 1 8 TO 3162 G 24546 C3 1 8 TO 5112 G 24546 C3 1 8 TO 1962 G 24546 C3 1 8 TO 1003 G 24546 C3 1 8 TO 1003 G 24546 C3 1 8 TO 5112 G 24546 C3 1 8 TO 1473 G 24546 C3 1 8 TO 5111 G 24546 C3 1 8 TO 5111 G 24546 C3 1 8 TO 5112 G 24546 C3 1 8 TO 1002 G 24546 C3 1 8 TO 1003 G 16299 C4 1 8 TO 1963 F 24546 C3 1 8 TO 1002 G 24546 C3 1 8 TO 1002 G 24546 C3 1 8 TO 6811 G 24546 C3 1 8 TO 8251 G MODEL 8640B OPTION 004 REFERENCE DESIGNATION A8A2R31 A8A2R32 A8A2R33 A8A2R34 A8A2R35 A8A2R36 A8A2R37 A8A2R38 A8A2R39 A8A2R40 A8A2R41 A8A2R42 A8A2R43 A8A2R44 A8A2R45 A8A2R46 A8A2R47 A8A2R48 A8A2R49 A8A2R50 A8A2R51 A8A2R52 A8A2R53 A8A2R54 A8A2R55 A8A2R56 A8A2R57 A8A2S1A A8A2S1B A8A2S1C A8A2TPl A8A2TP2 A8A2TP3 A8A2TP4 A8A2TP5 A8A2TP6 A8A2U1 A8A2U2 A8A2U3 A8A2U4 A8A2U5 A8A2U6 A8A2U7 A8A2U8 A8A2U9 A8A2U10 A8A2U11 A8A2U12 A8A2U13 A8A2U14 A8A2U15 A8A2U16 A8A2U17 A8A2U18 A8A2U19 A8A2U20 A8A2U21 A8A2U22 A8A2U23 A8A2U24 A8A2U25 A8A2U26 A8A2U27 A8A2U28 A8A2U29 A8A2VR1 A8A2VR2 A8A3 A8A3C2 A8A3C3 A8A3C4 A8A3
222. 0757 0290 0757 0440 0757 0424 0757 0440 0757 0465 0757 0442 0757 0442 2100 2514 0698 31562 0757 0442 0698 3156 0757 0438 0698 3453 0698 3153 0757 0464 1 0757 0438 0757 0438 0757 0278 0757 0290 0698 0083 0757 0458 0757 0438 0757 0458 0698 3154 0757 0442 0757 0441 TABLE 6 3 DESCRIPTION CAPACITOR FXD 50 CAPACITOR FXD 1 CAPACITOR FXD 2 CAPACITOR FXD 47 CAPACITOR FXD 0 CAPACITOR FXD 0 CAPACITOR FXD 56 CAPACITOR FXD 1 CAPACITOR FXD CAPACITOR FXD 12 CAPACITOR FXD 51 CAPACITOR FXD 0 CAPACITOR FXD 47 DIODE SWITCHING DIODE SWITCHING DIODE SWITCHING DIODE SWITCHING DIODE STABISTOR DIODE STABISTOR DIODE SWITCHING DIODE SWITCHING DIODE SWITCHING DIODE STABISTOR DIODE SWITCHING DIODE STABISTOR DIODE SCHOTTKY DIODE SCHOTTKY DIODE SWITCHING RELAY REED 1C COIL FXD MOLDE COIL FXD MOLDE EXTRACTOR PC BOARD PIN DRIVE 0 250 EXTRACTOR PC BOARD PIN DRIVE 0 250 TRANSISTOR TRANSISTOR TRANSISTOR TRANSISTOR TRANSISTOR NPN D NPN 5 PNP 2 NPN D PNP S TRANSISTOR NPN S TRANISTOR PNP SI TRANSISTOR NPN S TRANSISTOR NPN S REPLACEABLE PARTS OOFF 10 250WVDC CER UF 10 35VDC TA SOLID 20 10 20VDC TA OOPF 10 18UF 10 1UF 10 200WVDC POLYE PF 5 300WVDC MICA UF 10 35VDC TA SOLID 01UF 80 20 100WVDC CER 200WVDC POLYE OOPF 10 OPF 5 100WVCC MICA 2U 20 100WVDC VER OOPF 10 2NS 2NS 2NS 2NS 10 30V 50MA 30 50MA 30V 50M
223. 0757 0416 A8A1R9 0757 0416 A8A1R10 0757 1094 A8A1R11 0757 0416 A8A1R12 0698 7221 2 A8A1R13 0698 7197 1 A8A1R14 0698 7221 8 101 1820 0736 2 8 102 1820 1003 1 A8A1U3 1820 0145 6 A8A1U4 1820 0102 6 A8A1U5 5086 7089 1 A8A2 08640 60027 1 A8A2 08640 60087 A8A2C1 0160 3456 A8A2C2 0160 3094 19 A8A2C3 0160 3094 A8A2C4 0180 0049 1 A8A2C5 0180 1735 A8A2C6 0180 0197 A8A2C7 0160 3456 A8A2C8 0180 0228 A8A2C9 0180 0228 A8A2C10 0160 3455 2 TRANSISTOR NPN TRANSISTOR NPN RESISTOR 1K 2 NOT ASSIGNED NOT ASSIGNED RESISTOR 3 16K RESISTOR 3 16K RESISTOR 100 RESISTOR 51 1 RESISTOR 511 RESISTOR 511 RESISTOR 1 47K RESISTOR 511 RESISTOR 237 RESISTOR 23 7 RESISTOR 237 IC DGTL COUNTE IC DGTL COUNTE OC DGTL MC 101 IC DGTL MC 101 TRIGGER AMPLIF COUNTER LOCK Bi RESTORED 08640 CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD SI TO 18 PD 360MW SI TO 18 PD 360MW 05W F TUBULAR 2 05W F TUBULAR 2 05W F TUBULAR HM 2 05W F TUBULAR OHM 1 125W F TUBULAR HM 1 125W F TUBULAR HM 1 125W F TUBULAR 1 125W F TUBULAR HM 1 125W F TUBULAR HM 2 0 05 F TC 100 2 0 05W F TC 100 HM 2 0 05W F TC 100 R R OP GATE 3P FLIP FLOP IER OARD ASSY 60027 REQUIRES EXCHANGE 1000PF 10 1000WVDC CER lUF 10 100WVDC CER IUF 10 100WVDC CER 200 75 10 50VDC AL 22 10
224. 08640 80003 50864 3 08640 60165 150D105X9035A2 1500105 9035 2 1500105 9035 2 0160 2055 MODEL 8640B OPTION 004 REFERENCE DESIGNATION A26A4C6 A26A4C7 A26A4C8 A26A4C9 A26A4C10 26 4 11 A26A4C12 A26A4C13 A26A4C14 A26A4C15 A26A4C16 A26A4C17 A26A4C18 A26A4CR1 A26A4CR2 A26A4CR3 A26A4CR4 A26A4CR5 A26AA4CR6 A26A4CR7 A26A4CR8 A26AA4CR9 A26A4CR10 A26AA4CR11 A26AA4CR12 A26A4CR13 A26A4CR14 A26AA4CR15 A26A4K1 A26A4L1 A26A4L2 A26A4MP1 A26A4MP2 A26A4Q1 A26A4Q2 26 403 26 404 26 405 26 406 26 407 26 408 A26A4Q9 A26A4R1 A26A4R2 A26A4R3 A26A4R4 A26A4R5 26 4 6 A26A4R7 A26A4R8 A26A4R9 A26A4R10 A26A4R11 A26A4R12 A26A4R13 A26A4R14 A26A4R15 A26A4R16 A26A4R17 A26A4R18 A26A4R19 A26A4R20 A26A4R21 A26A4R22 A26A4R23 A26A4R24 A26A4R25 A26A4R26 A26A4R27 A26A4R28 A26A4R29 A26A4R30 HP PART NUMBER QTY 0160 34581 0180 0291 0180 0197 0160 01572 0160 03021 0160 0161 0140 0191 0180 0291 0160 2055 0160 02971 0160 3534 0160 34591 0160 0157 1901 0040 1901 0040 1901 0040 1901 0040 1901 0022 1901 0022 1910 00163 1910 0016 1910 0016 1901 0022 1901 0040 1901 0022 1901 0539 1901 05181 1901 0040 0490 1080 9100 1641 9100 1641 4040 0749 1480 0073 4040 0753 1480 0073 1854 0221 1854 0071 1853 0007 1854 0221 1853 0034 1854 0071 1853 0034 1854 0071 1854 0071 2100 24891 2100 2521 0757 0401 0757 0290
225. 1 A26A3L2 A26A3R1 A26A3R2 A26A3R3 A26A3R4 A26A3R5 A26A3T1 A26A3T2 A26A3XU2A E A26A4 26 4 1 A26A4C2 A26A4C3 A26A4C4 26 4 5 0757 0280 0698 3440 0757 0438 2100 2413 1 0698 3157 0757 0416 0757 0394 0698 3162 0757 0438 0698 3162 0757 0438 0698 0085 0698 3162 0698 3150 0757 0438 0698 3154 0757 0438 0698 3450 0757 0289 0698 0082 0698 0083 0757 0442 0757 0438 0698 0083 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 1826 0114 1 1820 0448 1 1820 0579 1 1902 3139 1 08640 600161 0160 3094 0160 3094 0150 0048 4 0150 0048 0150 0048 0150 0048 08640 601631 1250 1425 1 9100 1620 9140 0112 1 0698 7229 0698 3132 0698 3132 0757 0416 0757 0416 08640 800032 08640 80003 1251 2613 08640 601651 0180 0291 0180 0291 0180 0291 0160 2055 TABLE 6 3 REPLACEABLE PARTS DESCRIPTION RESISTOR 1K 1 125W F TUBULAR RESISTOR 196 OHM 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR VAR TRMR 200 OHM 10 C RESISTOR 19 6K 1 125W F TUBULAR RESISTOR 511 OHM 1 125W F TUBULAR RESISTOR 51 1 OHM 1 125W F TUBULAR RESISTOR 46 4K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 46 4K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 2 61K 1 125W F TUBULAR RESISTOR 46 4K 1 125W F TUBULAR RESISTOR 2 37K 1 125F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RES
226. 1 Connect the equipment as shown in Figure 5 3 after setting the Signal Generator controls as follows Meter Function x LEVEL COUNTER MODE EXPAND Off LOCK x Xx 4 x 3 2 OFF Source 2 a ow e oco MODULATION Centered eee he sw OFF RANGE 2 2 128 256 MHz FREQUENCY 200 s s s 190 2 MHz OUTPUT LEVEL Switches 2 s s s s 720 dBm 20 0 OUTPUT LEVEL Vernier CAL RF ON OFF Adjustments Model 8640B Option 004 5 31 2 10 11 12 13 5 18 ADJUSTMENTS PRELIMINARY AM ADJUSTMENTS Cont d With the RF set to OFF connect a clip lead from DET A26A8TP2 to ground Connect the DVM to BUFFER DET 26 8 and set to read dc volts Adjust BUFFER OFFSET A26A8R3 to give a reading of 0 1 mVdc Set the AC DC switch A26A8S1 to DC and adjust the DC OFFSET A26A8RI15 for 0 1 mVdc at DEMOD A26A8TP3 Unclip the ground lead to A26A8TP2 Set RF ON OFF to ON Set the DVM to read ac volts and connect it to AM IN A26A2TPI Set the test oscillator for approximately 0 4 Vrms at 100 Hz Set AM to DC ad adjust the MODULATION control for a reading of 353 6 0 5 mVrms at A26A2TPI Set the DVM to read dc volts and connect it to AM OUT A26A2TP3 Record the voltage should be between 1 9 and 2 1 Vdc Vdc at A26A2TP3__ Vdc Multiply the voltage from
227. 1 LA 851 LA 851 LA 851 221 68 143 953 220 502 C4 1 8 TO 10R0 F 08640 60046 150D224X9035A2 150D224X9035A2 150D684X9035A2 150D335X9050B2 30D506G050DD2 150D157X9006R2 HEW 238T 150D225X9035B2 0160 2204 30D506G050DD2 150D157X9006R2 0160 2204 150D606X9006B2 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0025 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 3728104 2 0490 1080 MODEL 8640B OPTION 004 TABLE 6 3 REPLACEABLE PARTS REPLACEABLE PARTS MFR MFR PART NUMBER CODE 28480 4040 0751 00000 OBD 28480 4040 0748 00000 OBD REFERENCE HP PART QTY DESCRIPTION DESIGNATION NUMBER 7 4040 0751 1 BD ORN LEXAN 062 BD THKNS 1480 0073 PIN DRIVE 0 250 LG 7 2 4040 0748 3 EXTRACTOR BOARD BLACK 1480 0073 PIN DRIVE 0 250 LG 701 1854 0071 TRANSISTOR NPN SI PD 300MW FT 200MHZ 702 1854 0071 TRANSISTOR NPN SI PD 300MW FT 200MHZ 703 1854 0022 TRANSISTOR NPN SI 0 39 PD 700MW 1200 0173 INSULATION XSTR TO 5 075 THK 704 1853 0020 11 TRANSISTOR PNP SI CHIP PD 300MW 705 1854 0071 TRANSISTOR NPN SI PD 300MW FT 200MHZ 706 1853 0038 TRANSISTOR PNP SI CHIP 0 39 PD 1W 1200 0173 INSULATION XSTR TO 5 075 THK 707 1853 0020 TRANSISTOR PNP SI CHIP PD 300MW 708 1853 0020 TRANSISTOR SI CHIP PD 300MW 7 1 0698 3162 RESISTOR 46 4K
228. 1 Amplifier 7 A26U2 Amplifier 8 A26J1 RF Connector 9 A26MP26 Coaxial Cap A26W2 Cable Assembly A26W1 Cable Assembly A26W4 Cable Assembly A26W3 Cable Assembly A26MP1 Gasket A26MP2 Gasket 26 Gasket A26MP4 Gasket 2 A26L1 3 6 L8 Inductor A26L2 Inductor A26L7 Inductor P OA26U1 2 Heat Sink A26MP5 Cover A26MP6 Cover A26MP7 Cover A26MP8 Casting A26MP9 Cover A26A5 Riser Board A26A6 Mother Board A26A2 AM OFF PUL Assembly A26A4 AGC Amplifier Assembly 2 A26A3 Modulator Assembly 26 1 Power Amplifier Detector Assembly N N A26MP10 Cover gt 93 x8 A26MP11 Guide NS N A26MP12 Guide Sy 3 A26MP13 Guide amp lt 26 14 Machine Screw INE A26MP15 Machine Screw SES A26MP16 Machine Screw 8 A26MP17 Hex Nut N 26 18 Lockwasher S A26MP19 Lockwasher x Sk A26MP20 Lockwasher x A26MP21 Lockwasher R A26MP22 Washer A26MP23 Hex Nut A26MP24 Lockwasher A26MP25 Blind Dome Rivet A26A8 Demodulator Amplifier Assembly im A26MP26 Guide Figure 8 89 A26 AM AGC and RF Amplifier Illustrated Parts Breakdown 8 81 A26 Assembly Removal and Disassembly 4 SERVICE SHEET F Service SERVICE SHEET G General Removal Procedures Top and Bottom Cover Removal CAUTION Before attempting to disassemble or re move any part of the generator remove line power from the instrument by dis connecting the instrument s line power cable from the line power outlet Remove top cover by removi
229. 1 ppm Stability vs Modulation Mode Change CW to FM lt 17 of selected peak deviation or 200 Hz whichever is greater DESCRIPTION A frequency counter is used to measure frequency shift as the output load is changed by means of an adjustable stub as RF OUTPUT LEVEL is changed 6 dB and as modulation mode is changed from CW to FM The frequency is monitored at the rear panel auxiliary RF output jack See Recommended Test Abridgements COUNTER INPUT 500 MODEL 8640B OPTION 004 AUX RF OUTPUT REAR PANEL 9o 0 99 Figure 4 4 Frequency Stability us Load Level and Mode Test Setup EQUIPMENT Frequency Counter HP 5327C Adapter Male to GR 874 HP 1250 0874 Adjustable Stub wx General Radio 874 DSOL PROCEDURE 1 Connect equipment as shown ih Figure 4 4 after setting Signal Generator s controls as follows FM OFF RANG E DI 1 1 1 256 512 MHz FREQUENCY 512 MHz OUTPUT LEVEL Switches 16 dBm OUTPUT LEVEL Vernier CAL RF ON OFF 2 Slowly slide adjustable stub through its range and note maximum and minimum counter readings The difference in counter readings should be less than 512 Hz 512 Hz 4 20 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 18 FREQUENCY STABILITY VS LOAD LEVEL AND MODE TEST Cont d 3 Remo
230. 100 OHM 1 125W F TUBULAR A7R30 0757 0403 RESISTOR 121 OHM 1 125W F TUBULAR ATR31 0757 0399 RESISTOR 82 5 OHM 1 125W F TUBULAR 7 32 0757 0395 1 RESSITOR 56 2 OHM 1 125W TUBULAR ATR33 0698 3435 1 RESISTOR 38 3 OHM 1 125W F TUBULAR ATR34 0698 3432 2 RESISTOR 26 1 OHM 1 1 25W F TUBULAR ATR35 0757 0294 1 RESISTOR 17 8 OHM 1 125W F TUBULAR ATR36 0698 3427 1 RESISTOR 13 3 OHM 1 125W F TUBULAR ATR37 0757 0346 RESISTOR 10 OHM 1 125W F TUBULAR 7 38 0757 0401 RESISTOR 100 OHM 1 125W TUBULAR ATR39 0757 0280 RESISTOR 1K 1 125W F TUBULAR A7TR40 0757 0200 2 RESISTOR 5 62K 1 125W F TUBULAR 7 41 2100 3109 RESISTOR VAR TRMR 2KOHM 10 SIDE ADJ ATR42 0757 0442 RESISTOR 10K 1 125W F TUBULAR ATRA3 0698 3155 RESISTOR 4 6K 1 125W F TUBULAR ATR44 0757 0443 RESISTOR 11K 1 125W F TUBULAR 7 45 0757 0460 RESISTOR 61 9 1 125W TUBULAR ATR46 0757 0123 RESISTOR 34 8K 1 125W F TUBULAR 47 0698 3449 4 RESISTOR 28 7 1 125W TUBULAR 7 48 0757 0199 RESISTOR 21 5K 1 125 TUBULAR ATR49 0698 3136 1 RESISTOR 17 8K 1 125W F TUBULAR 7 50 0757 0442 RESISTOR 10K 1 125W TUBULAR 7 51 0757 0440 RESISTOR 7 5K 1 125W TUBULAR ATR52 0757 0200 RESISTOR 5 62K 1 125W F TUBULAR A7R53 0698 3151 2 RESISTOR 2 87K 1 125W F TUBULAR ATR54 0757 1094 RESISTOR 1 47K 1 125W F TUBULAR ATR55 0757 0401 RESISTOR 100 OHM 1 125W F F TUBULAR ATR56 0698 3432 RESISTOR 26 1 OHM 1 125W F TUBULAR 7 57 0698 3433 1 RE
231. 101 0070 3101 0163 3101 0973 3101 1395 3101 1728 3130 0445 3130 0446 3140 0490 3339H 1 103 36D392G050AC2B 36D822G025AC2A 37JR104 2 PART NUMBER NATIONAL STOCK NUMBER TABLE 6 5 CROSS REFERENCE INDEX FSCM 28480 28480 00779 00779 56489 56289 56289 56289 32997 32997 32997 32997 28480 28480 28480 28480 28480 28480 28480 28480 28480 32997 56289 56289 24931 NATIONAL STOCK NUMBER 5935 00 974 6874 5935 00 565 8380 5935 00 188 0135 5935 00 267 2973 5935 00 405 7720 5935 00 236 7955 5935 00 446 8768 5310 00 450 3324 5310 00 454 1335 5999 00 137 1142 5935 00 104 1184 5910 00 827 1209 5910 00 027 7069 5910 00 879 0123 5910 00 138 7324 5905 00 107 4881 5905 00 243 1778 5905 00 359 5421 5905 00 428 5335 5930 01 037 6226 5930 00 919 1755 5930 00 490 4829 5930 00 455 0120 5930 00 164 0850 5930 01 025 9369 5930 00 574 4432 5930 00 574 4437 6105 00 032 0345 5905 01 020 9348 5910 00 103 7651 5910 00 127 1848 5935 00 068 3546 4 4 4 4 4 4 4 50 045 4610 50 051 0109 5000 0051 5040 0170 5040 0218 5040 0306 5040 0447 5060 0109 5060 0222 5060 0767 50864 3 550 683 710HM 7101 723BE 8120 1378 8120 1829 8120 1830 8120 1831 8120 1832 8120 1887 8120 1892 8120 1905 8123 UMBER 040 0 040 0 040 0 04
232. 101 09731 0360 1514 0360 1514 0360 1514 1820 0158 1820 00811 1902 0202 1902 0202 TABLE 6 3 DESCRIPTION REPLACEABLE PARTS RESISTOR RESISTOR 8 25K 1 125F W TUBULAR 75K 1 125W F TUBULAR RESISTOR 619 OHM 1 125W F TUBULAR RESISTOR 75K 1 125W F TUBULAR RESISTOR VAR TRMR 50KOHM 10 C SIDE ADJ SWITCH SL DPOT NS 5A 125VAC DC TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD IC LIN LM302 FOLLOWER IC DGTL GATE DIODE DIODE ZENER ZENER 15V VZ 15V VZ 1W MAX PD 1W MAX PD MFR CODE 245446 24546 24546 24546 32997 79727 28480 28480 28480 27014 07263 04713 04713 REPLACEABLE PARTS MFR PART NUMBER C4 1 8 T0 8251 F C4 1 8 T0 7502 F C4 1 8 T0 619R F C4 1 8 T0 7502 F 3006P 1 503 GF126 0018 0360 1514 0360 1514 0360 1514 LM302H 911HC 5211213 191 5211213 191 MODEL 8640B OPTION 004 REFERENCE DESIGNATION C2 c3 C4 c5 C6 DS1 FT J1 J2 J3 44 J5 J6 J7 M1 MP1 MP2 MP3 MP4 MP5 MP6 MP7 MP8 MP9 MP10 MP11 MP12 MP13 MP14 MP15 MP16 MP17 MP18 MP19 MP20 MP21 MP22 MP23 MP24 MP25 MP26 MP27 MP28 MP29 MP30 MP31 MP32 MP33 MP34 MP35 MP36 HP PART NUMBER QTY 0180 2530 2 0180 2530 0180 2334 1 0180 2277 2 0180 2277 0160 4048 1 2140 0244 1 2110 0002 1 2110 0094 1 1120 0539 1 0360 0053 1 0340 0486 1 0370 2376 1 0370 2378 1 0370 23
233. 10A1L22 A10A1L23 A10A1L24 A10A1L25 A10A1L26 A10A1L27 A10A1L28 A10A1L29 A10A1L30 10 1131 A10A1L32 A10A1L33 A10A1L34 A10A1L35 A10A1L36 A10A1L37 A10A1L38 A10A1L39 10 1140 10 1141 10 1142 10 1143 10 1144 10 1145 10 1146 10 1147 10 1148 10 1149 10 1150 10 1151 10 1152 10 1153 10 1154 10 1 10 1 2 10 1 10 1 4 10 1 5 0180 0197 0160 0174 0180 0197 0160 0174 0180 0197 0160 2055 0160 0204 0160 0204 0160 0204 1250 1220 1250 1220 1250 1220 1250 1220 0490 1073 0490 1073 0490 1073 0490 1073 9100 3375 9100 3365 9100 3375 9100 3361 9100 3362 9100 3361 9100 3364 9100 3374 9100 3363 9100 3369 9100 3370 9100 3369 9100 3368 9100 3367 9100 3368 9100 3374 9100 3372 9100 3373 9100 3359 9100 3360 9100 3359 9100 3357 9100 3358 9100 3357 9100 3372 9100 3370 9100 3371 9100 3355 9100 3356 9100 3355 9100 3513 9100 3513 9100 3513 9100 3370 9100 3365 9100 3366 9100 3512 9100 3512 9100 3512 9100 3514 9100 3514 9100 3514 9100 3514 9100 3514 9100 3514 9140 0144 9140 0144 08640 80001 08640 80001 08640 80001 08640 80001 1480 0352 08443 20003 08640 00029 08640 20082 08640 20083 QTY e ENEN PR TABLE 6 3 REPLACEABLE PARTS DESCRIPTION CAPACITOR FXD 2 20 10 20VDC CAPACITOR FXD 47UF 80 20 25WVDC CER CAP
234. 1R3 0698 0096 1 RESISTOR 968 OHM 1 125W F TUBULAR 03888 PME55 I 8 TO 9680 F A1R4 0698 3495 1 RESISTOR 866 OHM 1 125W F TUBULAR 16299 C4 1 8 T0 866R F 1 5 0698 4462 1 RESISTOR 768 OHM 1 125W F TUBULAR 24546 C4 1 8 T0 768R F A1R6 0757 0419 1 RESISTOR 681 OHM 1 125W F TUBULAR 24546 C4 1 8 T0 681R F A1R7 0698 3162 7 RESISTOR 46 4K 1 125W F TUBULAR 16299 C4 1 8 T0 4642 F A1R8 0757 0418 2 RESISTOR 619 OHM 1 125W F TUBULAR 24546 C4 1 8 T0 619R F 1 9 0698 7676 1 RESISTOR 546 OHM 1 125W TUBULAR 19701 MF 4C1 8 TO 546R F A1R10 0698 3178 1 RESISTOR 487 OHM 1 125W F TUBULAR 16299 C4 1 8 T0 487R F 1 11 0757 0414 1 RESISTOR 432 OHM 1 125W TUBULAR 24546 C4 1 8 T0 432R F A1R12 0698 3446 3 RESISTOR 383 OHM 1 125W F TUBULAR 16299 C4 1 8 T0 383R F A1R13 0698 3445 5 RESISTOR 348 OHM 1 125W TUBULAR 16299 C4 1 8 T0 348R F 1 14 0698 4449 1 RESISTOR 309 OHM 1 125W F TUBULAR 16299 C4 1 8 T0 309R F 1 15 0698 6250 1 RESISTOR 2 5K 1 125W F TUBULAR 24546 C4 1 8 T0 2501 F 151 3130 0485 1 SWITCH ROTARY WAFER 28480 3130 0485 A1S1B 3130 0486 1 SWITCH ROTARY WAFER 28480 3130 0486 A1S1C 3130 0487 1 SWITCH ROTARY WAFER 28480 3130 0487 1 1 08640 60063 1 ATTENUATOR ASSY 28480 08640 60063 1 1 91 NSR P O 1 1 A1A1J2 NSR P O 1 1 A2 08640 60055 1 BOARD ASSY METER SELECT 28480 08640 60055 2 1 0160 0128 CAPACITOR FXD 2 2UF 20 25WVDC CER 28480 0160 0128 A2C2 0180 1746 4 CAPACITOR FXD 150 10 20VDC T
235. 1W3 10 1 10 10 1 10 A10A2 10 2 1 A10A2C2 A10A2C3 10 2 4 A10A2C5 A10A2C6 A10A2C7 A10A2C8 A10A2C9 A10A2C10 10 2 11 A10A2C12 A10A2C13 A10A2C14 A10A2C15 A10A2C16 A10A2C17 A10A2C18 A10A2C19 A10A2C20 A10A2C21 A10A2C22 A10A2C23 A10A2C24 A10A2C25 A10A2C26 A10A2C27 A10A2C28 A10A2C29 A10A2C30 A10A2C31 A10A2C32 A10A2C33 A10A2C34 A10A2C35 A10A2C36 A10A2C37 A10A2C38 A10A2C39 A10A2C40 HP PART NUMBER 08640 20200 08640 20214 08640 20219 08640 40004 08640 20064 2200 0105 08640 20133 3030 0007 2200 0145 08640 20206 0510 0015 0757 0346 0757 0346 0757 0346 0757 0346 0757 0346 0757 0346 0757 0346 0757 0346 0757 0346 08640 60106 08640 60106 08640 60106 08640 60106 08640 60106 08640 60106 8120 1830 8120 1832 8120 1831 1251 2035 1251 2026 08640 60023 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 2055 0160 2055 0160 3456 0160 2055 0160 3456 0160 3456 0160 3456 0180 0100 0160 3456 0180 0100 0180 0197 0180 0374 0180 1743 0180 0374 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 2055 0160 2055 0160 2055 0160 2055 0160 2055 QTY 11 TABLE 6 3 REP DESCRIPTION CAST COVER BUSHING CAM H COVER CAM FOLLOWER CAM CAM SLIDER LACEABLE PARTS TTOM D F OUSING SCREW MACH 4
236. 2 A12CR13 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 Al2CR14 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 Al12CR15 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 A12CR16 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 12 17 1901 0418 DIODE PWR RECT 400 1 5A 04713 SR1846 12 A12CR18 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 Al2CR19 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 A12CR20 1901 0418 DIODE PWR RECT 400V 1 5A 04713 SR1846 12 12 1 0403 0026 4 GLIDE NYLON 28480 0403 0026 A1201 NOT ASSIGNED Al2R1 NOT ASSIGNED A12R2 NOT ASSIGNED 1263 0757 0199 RESISTOR 21 5K 1 125W TUBULAR 24546 C4 1 8 TO 2152 F A12R4 0757 0442 RESISTOR 10K 1 125W F TUBULAR 24546 C4 1 8 TO 1002 F 1265 0757 0442 RESISTOR 10K 1 125W TUBULAR 24546 C4 1 8 TO 1002 F 1266 0757 0442 RESISTOR 10K 1 125W TUBULAR 24546 C4 1 8 TO 1002 F A12R7 0757 0442 RESISTOR 10K 1 125W F TUBULAR 24546 C4 1 8 TO 1002 F A12VR1l NOT ASSIGNED A13 08640 600571 BOARD ASSY MODULATION METERING MOTHER 28480 08640 60057 13 1 0180 2208 5 CAPACITOR FXD 220UF 10 10VDC 56289 150D227X901052 A13C2 0180 2208 CAPACITOR FXD 220UF 10 10VDC TA 56289 150D227X901052 A13C3 0180 2208 CAPACITOR FXD 220UF 10 10VDC TA 56289 150D227X901052 13 4 0180 2208 CAPACITOR FXD 220UF 10 10VDC TA 56289 150D227X901052 A13J1 1250 0257 3 CONNECTOR RF SMB M PC 28480 1250 0257 A13J2 1251 3055 2 CONNECTOR STRIP 8 MALE CONTACT 74868
237. 2 0698 7188 0698 3445 0698 7214 0698 7224 0757 0422 0698 7193 0698 3445 0698 7214 08640 00007 08640 60037 0160 3456 0160 3456 0160 3878 0160 3456 0160 3456 0160 3878 0160 3456 9140 0142 9140 0142 1200 0173 1854 0247 1854 0247 0757 0422 0698 7212 0698 7188 0698 3445 0698 7216 0698 7224 0757 0422 0698 7193 0698 3445 0698 7196 0698 7196 0698 7205 08640 00007 08640 60196 2100 3054 2100 3109 2100 3123 2100 3154 QTY 41 1 TABLE 6 3 REPLACEABLE PARTS DESCRIPTION RF DIVISION FILTER BUFFER AMPLIFIER ASSY CAPACITOR FXD 1000 10 1000WVDC CER CAPACITOR FXD 1000PFD 1000PF 10 1000WVDC CER CAPACITOR FXD 1000PF 20 100WVDC CER CAPACITOR FXD 1000 10 1000WVDC CER CAPACITOR FXD 1000PF 10 1000WVDC CER CAPACITOR FXD 1000PF 20 100WVDC CER CAPACITOR FXD 1000PF 10 1000WVDC CER CAPACITOR FXD 4 7PF 5 200WVDC CER CAPACITOR FXD 47PF 20 200WVCC CER COIL FXD MOLDED PF CHOKE 2 2UH 10 COIL FXD MOLDED RF CHOKE 2 2UH 10 INSULATOR XSTR TO 5 075 THK TRANSISTOR NPN SI TO 39 PD 1W FT 800MHZ TRANSISTOR NPN SI TO 39 PD 1W FT 800MHZ RESISTOR 909 OHM 1 125W F TUBULAR RESISTOR 100 OHM 2 05W F TUBULAR RESISTOR 10 OHM 2 05W F TUBULAR RESISTOR 348 OHM 1 125W F TUBULAR RESISTOR 121 OHM 2 05W F TUBULAR RESISTOR 316 OHM 2 05W F TUBULAR RESSITOR 909 OHM 1 125W F TUBULAR RESISTOR 16 2 OHM 2 05W F TUBULAR RESISTOR 348 OHM 1 12
238. 2 Adjust OSC LEVEL adjustment Al1R6 for a 840 10 mVrms reading on DVM at A11TP3 3 Connect DVM through 600 ohm feedthrough to AM OUTPUT Set AUDIO OUTPUT LEVEL to 100 mVrms as read on DVM The AUDIO OUTPUT LEVEL dial should read 100 mVrms If it does not loosen setscrews on knob and align knob so that it does 4 Set MODULATION FREQUENCY to 400 Hz Set AUDIO OUTPUT LEVEL fully cw The DVM should read 1 Vrms Vrms 5 27 VARIABLE FREQUENCY MODULATION OSCILLATOR ADJUSTMENT OPTION 001 REFERENCE Service Sheet 9A DESCRIPTION A digital voltmeter and a frequency counter are used to monitor output voltage and frequency while adjusting the oscillator The MODULATION FREQUENCY dial and the AUDIO OUTPUT LEVEL dial are adjusted EQUIPMENT Digital Voltmeter HP 3480D 3484A Option 043 Frequency Counter bo cee e Sekt dde ser ub ed el CHIP 59327 600 Ohm Feedthrough HP 11095A PROCEDURE l Check that modulation oscillator is installed with all of its covers in place 2 the knobs have been removed turn MODULATION FREQUENCY vernier shaft fully cw Install frequency dial on vernier shaft so that the gears mesh and number 200 on the dial is 10 to 20 to the left ccw of the cursor Turn MODULATION FREQUENCY switch shaft fully ccw and install range knob on switch shaft so that 400 Hz FIXED FREQUENCY position is at the cursor top Install vernier knob The knobs should not tou
239. 2 3393 DIODE ZNR 75V 5 DO 7 PD 0 4W TC 0 077 Page 6 38 Table 6 3 Change A26 A4R34 and R35 to 0683 1055 RESISTOR 1M 5 0 25W CC TUBULAR Service Sheet 11 sehematic Change part number for A10A2US to 1820 0143 Service Sheet 12 schematic Change 26 A4R34 and R35 to 1MQ Service Sheet 17 component locations Replace Figure 8 57 with the attached figure 4 Figure 8 57 A4 Meter Annunciator Drive Assembly Component Locations P O Change 1 Continued 7 25 Model 8640B Option 004 08640 90073 CHANGE Cont d Service Sheet 17 schematic Replace appropriate portions of schematic with the attached partial schematics P O Figure 8 59 1 of 2 and 2 of 2 AUTORANGE A COMPARATOR TA P O Figure 8 59 Meter Circuits Schematic Diagram P O Change 1 1 of 2 A4 METER ANNUNCIATOR DRIVE ASSEMBLY 08640 60056 P O Figure 8 59 Meter Circuits Schematic Diagram P O Change 1 2 of 2 Continued Model 8640B Option 004 CHANGE 1 Cont d Service Sheet 20 Component Locations Replac Figure 8 66 with attached figure P O A8A2 08640 90073 Figure 8 66 P 0 A8A2 Counter Lock Board Assembly Component Locations P O Change 1 Service Sheet 20 schematic Change part number for A8A2 subassembly to 08640 60189 Continued 7 27 Model 8640B Option 004 08640 90073 CHANGE 1 Cont d Service Sheet 21 component locations Replac Figure 8 68 with attac
240. 20 35 vee TOP view FeO E a a 1 n 1 T GND 0 ae ip A25A2U3 VIFW 6 16 o 10 16 9 2060 SU FSI 2 1 2 GND 2060 30 20 10 A26A1 06 A26A2UI TOP VIEW TOP VIEW REFERENCE DESIGH ATIONS WITHIN OUTLINED 1 m m 1 ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IH CLUDES aSSEMBLY HUMBER DF ASSEMBLY al I AIR DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE 4 SHOWN 5 13 ATA 1941 26 A26A2 Figure 8 49 RF Amplifier Pulse Switching und Step Attenuators Schematic Diagram 8 45 RF Amplifier Pulse Switching and Step Attenuators 1 1 A19A1 A26 A26A1 A26A2 SERVICE SHEET 13 oervice SERVICE SHEET 14 PRINCIPLES OF OPERATION AM Offset A26A2 The AM Offset Amplifier establishes the AGC reference for the output leveling system and superimposes on it the AM modulation signal The modulation signal is coupled into the amplifier through slide switch A1352C and MODULATION potentiometer R2 The amplifier input stage is the differential transistor pair Q1B Tran sistor Q2 is a constant current source for the emit ters of Q1 Transistors Q3 and Q4 form a second dif ferential amplifier stage Transistor Q5 is a common emitter output stage Resistors R16 R19 and R38 form a resistive feedback divider The ac voltage gain 2 is adjusted by R19 Transistor Q6 is a constant current source T
241. 20 and A22 should light Connect DVM to each of the test points listed below The voltages should be within the tolerances shown if not adjust appropriate resistor for a reading within the indicated tolerances Test Point Adjust Voltage Level 18 5 A18R2 5 200V 10 mV A2OTPIO A20R16 5 200V 10 mV A22TP4 A22R7 20 000V 10 mv A22TP9 22 19 20 000 10 mV A20TP4 A20R8 44 600V 100 mV For ambient temperatures other than 25 C modify the voltage level setting by 4 2 mV C Perform FM CAL adjustment paragraph 5 40 step 5 time base adjustment paragraph 5 44 and AM accuracy Adjustment p Perform VARACTOR BIAS adjustment 5 40 step 11 and AM accuracy Adjustment palagraph 5 32 5 26 FIXED FREQUENCY MODULATION OSCILLATOR ADJUSTMENT REFERENCE Service Sheet 9 DESCRIPTION A digital voltmeter is used to monitor the audio oscillator s output while setting its level The AUDIO OUTPUT LEVEL dial is also adjusted EQUIPMENT Digital Voltmeter HP 3480D 3484A Option 043 600 Ohm Feedthrough HP 11095 5 8 Model 8640B Option 004 Adjustments ADJUSTMENTS 5 26 FIXED FREQUENCY MODULATION OSCILLATOR ADJUSTMENT Cont d PROCEDURE 1 Connect DVM to OUT Set Signal Generator s controls as follows AM INT MODULATION FREQUENCY 100 FM AUDIO OUTPUT LEVEL Do 1o fo ifo S cw
242. 20 Hz 1 51 Multi Function Meter and Annunciators 1 52 The front panel meter on the Signal Gener ator monitors the RF output level in dBm and volts the AM modulation percentage and the FM peak deviation in kHz or MHz The accuracy of this meter is usually better then 3 of reading Pushbuttons select the meter function and scale lights indicate the range on which the meter reading should be made For RF output level and AM the scales autorange for better resolution For FM the appropriate scale is selected by the PEAK DEVIATION range switch 1 53 Also provided are three front panel annunci ators that indicate when certain settings of RF level and modulation controls exceed specified limits Besides giving a warning indication the annunciators instruct the operator about returning the instrument to proper operation SPECIFIED gt FOR 3 1 kHz RATE lt gt lt FM DISTORTION 0 20 40 6 80 100 FM RATE kHz Figure 1 6 FM distortion vs FM rate measured in the 8 16 MHz band but applies to all bands sup plemental information only 1 54 The REDUCE PEAK POWER annunciator lights whenever the combined settings of RF output and AM modulation levels exceed allowable knits The specification allows for up to 100 AM on all RF output ranges except the 16 dBm range On the 16 dBm range RF levels with up to 50 AM are normally possible before the annunciator will light When the annunciator lights
243. 226 28480 0004 0004 24226 24226 24226 24226 24226 24226 24226 24226 84226 24226 24226 28480 28480 28480 28480 00000 28480 28480 28480 28480 REPLACEABLE PARTS MFR PART NUMBER 150D225X9020A2 0160 0174 150D225X902A02 0160 0174 150D225X9020A2 0160 2055 SMF8 A2 SMFB A2 SMFB A2 50 051 0109 50 051 0109 50 051 0109 50 051 0109 0490 1073 0490 1073 0490 1073 0490 1073 9100 3375 AE 500J P 9100 3375 AD 300J P AD 323J P AD 300J P 8 002 9100 3374 4 742 9100 3369 9100 3370 9100 3369 9100 3368 AE 646J P 9100 3368 9100 3374 9100 3372 9100 3373 AC 231J P AC 250Jg P 2310 AC 150Jg P AC 162J P AC 150Jg P 9100 3372 9100 3370 9100 3371 AC 115Jg P AC 125J P 1154 8123 2 8123 2 8123 2 9100 3370 AE 500J P AE 592J P 8123 1 8123 1 8123 1 8123 3 8123 3 8123 3 8123 3 8123 3 8123 3 10 471 10 471 08640 80001 08640 80001 08640 80001 08640 80001 1480 0352 08443 20003 08640 00029 08640 20082 08640 20083 MODEL 8640B OPTION 004 REFERENCE DESIGNATION 10 1 6 10 1 7 10 1 8 10 1 9 10 1 10 10 1 11 10 1 12 10 1 13 10 1 14 10 1 15 10 1 16 10 1 1 10 1 2 10 1 10 1 4 10 1 5 10 1 6 10 1 7 A10A1R8 10 1 9 10 151 10 152 10 153 10 154 A10A1S5 A10A1S6 A10A1Wl A10A1W2 A10A
244. 24546 24546 24546 16299 24546 24546 24546 01121 16299 16299 01121 16299 16299 24546 30983 24546 C4 1 8 TO 383R F C4 1 8 TO 751 F C4 1 8 TO 1331 F C4 1 8 TO 751 F C4 1 8 TO 1001 F C4 1 8 TO 8251 F C4 1 8 TO 287R F C4 1 8 TO 2152 F C4 1 8 TO 2152 F C4 1 8 TO 5112 F CB3355 C4 1 8 TO 4222 F C4 1 8 TO 4222 F CB1055 C4 1 8 TO 147R F C4 1 8 TO 2610 F C4 1 8 TO 5111 F ET50W201 C4 1 8 TO 1002 F MODEL 8640B OPTION 004 REPLACEABLE PARTS TABLE 6 3 REPLACEABLE PARTS REFERENCE HP PART QTY DESCRIPTION MFR MFR PART NUMBER DESIGNATION NUMBER CODE A26A1R21 0757 0420 RESISTOR 750 OHM 1 125W F TUBULAR 24546 C4 1 8 TO 751 F A26A1R22 NOT ASSIGNED A26A1R23 0683 1055 RESISTOR IM 5 25W CC TUBULAR 01121 CB1055 A26A1TP1 0340 0044 1 TERMINAL STUD DBL TURRET PRESS MTG 25 83330 92 1500 26 1 2 0360 1514 TERMINAL SLDR STUD 28480 0360 1514 A26A1VR1 1902 0184 1 DIODE ZNR 16 2V 5 00 7 PD 4W 28480 1902 0184 A26A1VR2 1902 0048 1 DIODE ZNR 6 81V 5 DO 7 PD 4W 28480 1902 0048 26 1 01 1251 2613 2 CONNECTOR 1 5 033 DIA 00779 50864 3 A26A2 08640 600141 AM OFFSET amp PULSE SWITCHING ASSY 28480 08640 60014 A26A2C1 0180 0291 CAPACITOR FXC 1UF 10 35VDC TA SOLID 56289 1500105 9035 2 A26A2C2 0180 0291 CAPACITOR FXD 10 10 35VDC TA SOLID 56289 1500105 9035 2 26 2 3 0180 0291 CAPACITOR FXD 1UF 10 35VDC TA SOLID 56289 1500105 9035 2 A26A2C4 0180 0291 CAPACITOR FXD 1UF 10 35VDC TA SOLID 5628
245. 28480 1990 0330 28480 1990 0330 28480 08640 60168 28480 08640 60097 56289 150D225X9020A2 56289 150D225X9020A2 28480 0160 3879 28480 0160 3879 28480 0160 3879 28480 0160 3877 28480 0160 3872 28480 1901 0050 28480 1901 0050 28480 1901 0050 28480 1901 0050 28480 1901 0050 98291 50 051 0109 98291 50 051 0109 28480 0490 1073 28480 0490 1073 28480 08640 20088 97300 SIZE A 97300 SIZE A 00000 OBD REFERENCE HP PART QTY DESIGNATION NUMBER A8MP31 2200 0140 1 A8MP 32 08640 00058 2 A8MP 33 2200 0105 A8MP 34 0520 0127 2 A8MP35 2190 0014 2 A8MP36 0516 0005 1 A8MP37 2200 0103 1 A8MP 38 2200 0155 2 A8MP39 0361 0207 1 A8MP 40 2200 0504 1 8 41 8 42 2190 0012 2 A8MP 43 2190 0057 1 8 44 2680 0128 1 A8MP45 08640 20088 2 801 1990 0330 6 A8U2 1990 0330 A8U3 1990 0330 A8U4 1990 0330 805 1990 0330 806 1990 0330 A8Al 08640 60168 1 A8Al 08640 60097 8 1 1 0180 0197 A8A1C2 0180 0197 A8A1C3 0160 3879 9 A8A1C4 0160 3879 A8A1C5 A8A1C6 0160 3879 A8A1C7 0160 3877 4 A8A1C8 0160 3872 1 A8A1CR1 1901 0050 A8A1CR2 1901 0050 A8A1CR3 1901 0050 A8A1CR4 1901 0050 A8A1CR5 1901 0050 1 1 1250 1220 6 A8A1J2 1250 1220 A8A1K1 0490 1073 6 A8A1K2 0490 1073 A8A1MP1 08640 20088 A8A1MP2 0360 0124 2 A8A1MP3 0360 0124 A8A1MP4 0361 0036 1 A8A101 1854 0404 A8A102 1854 0404 A8A1R1 0698 7236 2 A8A1R2 A8A1R3 A8A1R4 0698 7248 4 A8A1R5 0698 7248 A8A1R6 0698 7212 A8A1R7 0757 0394 A8A1R8
246. 2R27 A8A2R28 A8A2R29 A8A2R30 HP PART NUMBER 0160 3455 0160 3466 0160 2207 0160 3877 0160 3879 0160 3879 0160 0174 0160 3094 0160 2201 0180 0291 0180 0197 0160 3879 0180 0197 0160 2055 0160 2055 0160 2055 0160 2204 0160 3876 0160 3876 0160 3876 0160 3456 1901 0040 1901 0040 9100 1622 9100 1620 1854 0071 1853 0020 1853 0020 1854 0071 1854 0071 1855 0062 1853 0020 1854 0071 1854 0071 1854 0071 1854 0071 1854 0071 1853 0020 1854 0071 1854 0071 1853 0020 1853 0020 1854 0071 0698 3440 0757 0438 0698 7253 0698 7253 0698 7239 0698 7239 0698 7246 0698 7246 0698 7277 0698 7277 0683 8245 0683 8245 0698 7267 0698 7272 0698 7277 0698 7267 0698 7284 0698 7284 0698 7277 0698 7288 0698 7253 0698 7253 0698 7277 0698 7260 0698 7284 0698 3453 0698 7260 0698 7260 0698 7256 0698 7258 QTY TABLE 6 3 REP DESCRIPTION CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD DIODE SWITCHIN DIODE SWITCHIN COIL FXD MOLI COIL FXD MOLI TRANSISTOR NPN TRANSISTOR PNP TRANSISTOR PNP TRANSISTOR NPN TRANSISTOR NPN TRANSISTOR J TRANSISTOR PNP TRANSISTOR NPN TRANSISTOR NPN TRANSISTOR NPN TRANSIS
247. 2UH COIL FXD MOLDED RF CHOKE 000001UH COIL FXD MOLDED RF CHOKE 1 18UH 5 COIL FXD MOLDED RF CHOKE 12UH 5 COIL FXD MOLDED RF CHOKE 125UH 5 COIL FXD MOLDED RF CHOKE 125UH 5 COIL FXD 75UH 500VAC RMS 3 1 2 T COIL FXD 75UH 500VAC RMS 3 1 2 T COIL FXD 75UH 500VAC RMS 3 1 2 T COIL FXD MOLDED RF CHOKE 00001UH COIL FXD MOLDED RF CHOKE 5UH 5 COIL FXD MOLDED RF CHOKE 592UH 5 COIL FXD 50UH 500VAC RMS 2 1 2 T COIL FXD 50UH 500VAC RMS 2 1 2 T COIL FXD 50UH 500VAC RMS 2 2 2 T COIL FXD 30UH 500VAC RMS 1 1 2 T COIL FXD 30UH 500VAC RMS 1 1 2 T COIL FXD 30UH 500VAC RMS 1 1 2 T COIL FXD 30UH 500VAC RMS 1 1 2 T COIL FXD 30UH 500VAC RMS 1 1 2 T COIL FXD 30UH 500VAC RMS 1 1 2 T PART OF ETCHED CIRCUIT BOARD PART OF ETCHED CIRCUIT BOARD PART OF CIRCUIT BOARD COIL FXD MOLDED RF CHOKE 4 7UH 10 COIL FXD MOLDED RF CHOKE 4 7UH 10 TOROID FILTER TOROID FILTER TOROID FILTER TOROID FILTER PIN DETENT 0 055 X 0 750 DIA ROLLER DETENT SPRING DETENT SHAFT CAM SHAFT CAN FOLL 6 20 MFR CODE 56289 28480 56289 28480 56289 28480 01121 01121 01121 98291 98291 98291 98291 28480 28480 28480 28480 28480 0004 28480 0004 0004 0004 0004 28480 0004 28480 28480 28480 28480 0004 28480 28480 28480 28480 0004 0004 0004 0004 0004 0004 28480 28480 28480 0004 0004 0004 24226 24226 24
248. 3 COUPLER SHAFT Add MP82 08640 00037 INSULATOR BOTTOM COVER Change W4 to 08640 60180 Service Sheet 6 component locations Replac Figure 8 25 1 of 2 and 2 of 2 with the attached Figures 8 25A and 8 25B Service Sheet 6 schematic Replace appropriate portions of schematic with attached partial schematics P 1 of 2 and 2 of 2 Service Sheet 7 schematic Replace appropriate portion of schematic with attached partial schematic P O Figure 8 29 Service Sheet 8 component locations Replace Figure 8 31 1 of 2 and 2 of 2 with the attached Figures 8 3 A and 8 31B Service Sheet 8 schematic Replace appropriate portion of schematic with attached partial schematic P O Figure 8 33 Service Sheet 15 schematic Replace appropriate portion of schematic with attached partial schematic P O Figure 8 53 Service Sheet 19 schematic Replace appropriate portion of schematic with attached partial schematic P O Figure 8 64 Service Sheet 25 schematic Change 9 to A9A2PI Delete all wire color codes leading away from A9A2PI Change description at Pin 24 to read NON FUNCTIONING LINE Service Sheet D Illustrated Parts Breakdown Replac and associated text with attached figure and text Model 8640B Option 004 08640 90073 CHANGE 7 Cont d A9A1A2 Figure 8 25A A9A1A2 FM Gain Switch Board Assembly Component Locations P O Change 7 7 21 Model 8640B Option 004 08640 90073 CHANGE 7 Cont d
249. 3155 0698 3449 2100 3154 0757 0438 0811 2813 0757 01581 0757 0397 0698 3447 0811 16663 0757 0420 2100 3123 0698 3150 0757 0416 0698 3440 0757 0420 0811 2813 0757 0316 0757 0397 0698 3447 0811 1666 0811 1666 0698 7246 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 1826 0177 1826 0177 1902 0025 1902 32341 1902 02441 1902 33451 1902 3005 TABLE 6 3 DESCRIPTION CAPACITOR FXD 1000PF 10 CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD 2700PF 10 CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD DIODE PWR RECT DIODE SWITCHING 2NS DIODE PWR RECT DIODE SWITCHING 2NS DIODE SWITCHING 2NS PHOTO DEVICE PHOTO DEVIC FUSE 3A 125V FUSE 1A 125V EXTRACTOR P C SW PNP SI 3V SW PNP SI 3V REPLACEABLE PARTS 200WVDC POLYE 10VDC TA SOLID 75VDC TA WET 15VDC TA SOLID 200WVDC POLYE 33UF 10 330 20 22UF 10 2200 10 330 10 lUF 10 10VDC TA 10VDC TA SOLID 100WVDC CER 750MA 80V 200 750MA 80V 200MA 80V 200 400V 400V 05MW PD 05MW PD BOARD BLACK PIN DRIVE 0 250 LG EXTRACTOR PC BOARD GREEN PIN DRIVE 0 250 LG THRYISTOR SCR TRANSISTOR NPN INSULATOR XSTR TRANSISTOR NPN INSULATOR XSTR TRANSISTOR PNP INSULATOR XSTR TRANSISTOR PNP TRANSISTOR NPN THYRISTOR SCR RESISTOR 31 6K RESISTOR 147 OHM 1 RESISTOR 75K 1 RESISTOR 1 96K RESISTOR 1 96K
250. 4 55 56 57 58 60 61 62 0698 3243 0698 3260 0698 3334 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 PART NUMBER NATIONAL STOCK NUMBER TABLE 6 5 CROSS REFERENCE INDEX FSCM 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 NATIONAL STOCK NUMBER 5365 00 422 0240 5905 00 407 2349 5905 00 402 4264 5905 00 891 2808 5905 00 974 6075 5905 00 407 0052 5905 00 974 6073 5905 00 998 1814 5905 00 828 0388 5905 00 891 4247 5905 00 481 1357 5905 00 246 8634 5905 00 420 7130 5905 00 974 6081 5905 00 891 4215 5905 00 976 3418 5905 00 974 6084 5905 00 433 6904 5905 00 858 8927 5905 00 974 6078 5905 00 974 6082 5905 00 840 8162 5905 00 891 4227 5905 00 998 1809 5905 00 407 2350 5905 00 405 3724 5905 00 475 8180 5905 00 420 7136 5905 00 407 0105 5905 00 407 0076 5905 00 997 4071 5905 00 402 7080 NUMBER 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 0698 34 n NS 0698 4014 0698 4197 0698 4471 0698 7212 0698 722
251. 4 The main counter holds at 999999 while the stall counter counts 1 2 3 5 On count 4 of the stall counter the main counter s second decade counts dawn by one fie the display is 999989 6 10 The counter holds at 999989 while the stall counter counts 5 5 7 8 9 lion The main counter counts down normally OVERFLOW Initia conditions and settings OVER FLOW lamp lit DETECTOR with test points ungrounded A8A2 Set COUNTER MODE to INT and EXP X100 FLASH Initial conditions and settings Display flahses at approx OSCILLATOR Set COUNTER MODE Lo imately a 2 Az rate and A8A2 INT LOCK to ON and turn digits count up as FRE FREQUENCY TUNE ew QUENCY TUNE is turned cw 8 58 Mogel 60405 Option 004 Figure 8 65 A amp A4 Counter Display Assembly Component Locations P O 48 a 3 vef nr farni Figure 8 66 P O 8 2 Counter Lock Board Assembly Component Locations 0 8 1 emm STORAGE BUFFERS 1820 0701 COUNTER LOAD DELAYED LOCK H REFERENCE DESIGN ATIONS W THIM OUTLINED ASSEMBLIES ARE ABBREYIATED FULL DESIGNATION WH CLUDES ASSEMBLY NUMBER wg RI OF ASSEMBLY Al 15 AJRI DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS E c peri 1820 0174 s oU BASE CAL DEI gt i T j Jg gt m ce e on Li
252. 40 40067 3030 0007 3VH10 1JN12 251 06 30 261 5040 0327 143 953 220 502 221 68 1854 0063 1854 0063 1854 0250 1854 0063 1854 0063 2100 3325 C4 1 8 T0 2872 F 53 67280 121 A1H GF 126 0000 7101 9100 3350 8120 1378 8120 0660 C 8120 1890 1 08640 60127 8150 0447 8150 0496 8150 0498 8120 1881 8120 1882 8120 0580 8150 0447 8150 0496 8150 0498 MODEL 8640B OPTION 004 REFERENCE HP PART QTY DESIGNATION NUMBER 10 8120 0661 1 wil 8120 0663 1 W12 08640 601281 W13 8120 1182 1 W14 8120 0659 1 W15 08640 601241 W16 8120 1593 1 W17 08640 600591 118 8120 0662 1 01 XQ2 XQ3 4 XQ5 1200 0041 TABLE 6 3 DESCRIPTION REPLACEABLE PARTS CABLE ASSY COAX 5 409 CABLE ASSY COAX 2 864 CABLE ASSY AM INPUT OUTPUT CABLE SHIELD 2 COND 24AWG CABLE ASSY COAX 12 104 COUNTER INPUT CABLE CABLE CABLE CABLE ASSY EXTERNAL TIME BASE IN OUT SHLD 5 COND 22AWG ASSY DEMOD OUTPUT ASSY AN ASSY NOT ASSIGNED NOT ASSIGNED NOT ASSIGNED NOT ASSIGNED SOCKET ELEC MFR CODE 28480 28480 28480 83501 28480 28480 28480 28480 28480 XSTR 2 CONT T0 3 PKG SLDRO0014 REPLACEABLE PARTS MFR PART NUMBER 8120 0661 8120 0663 08640 60128 OBD 8120 0659 08640 60124 8120 1593 08640 60059 8120 0662 PTS 1 Model 8640B Option 004 Reference ea Description Designation Number Qty Code 08640 20075 99640 20231 08640 00026 5000 8705 5000 8707 08640 00003 08640 00004 5
253. 40 PANHD POZI REC SST 300 SUPPORT CLAMP SCREW SET 4 40 SMALL CUP PT HEX REC ALY SCREW MACH 4 40 PAN HD POZI REC SST 300 RETAINER SLID RETAINER RING RESISTOR 10 CHI RESISTOR 10 CHI RESISTOR 10 OHI RESISTOR 10 OHI RESISTOR 10 OHI RESISTOR 10 OHI RESISTOR 10 OHI RESISTOR 10 OHI RESISTOR 10 OHI SWITCH SLIDE SWITCH SLIDE SWITCH SLIDE SWITCH SLIDE SWITCH SLIDE SWITCH SLIDE CABLE COAX 50 CABLE COAX 50 CABLE COAX 50 CONNECTOR PC CONNECTOR PC RF DIVIDER ASS CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD NOT ASSIGNED CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD NOT ASSIGNED CAPACITOR XD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACTIOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD ER 125 DIA CAD PLT STL M 1 125W F TUBULAR M 1 125W F TUBULAR M 1 125W F TUBULAR M 1 125W F TUBULAR M 1 125W F TUBULAR M 1 125W TUBULAR M 1 125W F TUBULAR M 1 125W F TUBULAR M 1 125W F TUBULAR D F D F D F D F D F OHM 086 OD CHM 086 0D OHM 086 00 EDGE 15 CONT DIP SOLDER EDGE 18 CONT DIP SOL
254. 40B and must accompany it whenever it is transferred or turned in The illustrations will help you identify these items b Section III Basic Issue Items Not applicable These are the minimum essential items required to place the HP 8640B in operation to operate it and to perform emergency repairs Although shipped separately packed they must accompany the HP 8640B during operation and whenever it is transferred between accountable of ficers The illustrations will assist you with hard to identify kerns This manual is your authority to requisition replacement BII based on TOE MTOE authorization of the end item B 3 Explanation of Columns a Illustration This column is divided as follows 1 Figure number Indicates the figure number of the illustration on which the item is shown 2 Item number The number used to identify item called out in the illustration b National Stock Number Indicates the National stock number assigned to the item and which will be used for requisitioning c Description Indicates the Federal item name and if required a minimum description to identify the item The part number indicates the primary number used by the manufacturer which controls the design and charac teristics of the item by means of its engineering drawings specifications standards and inspection requirements to identify an item or range of items Following the part number the Federal Supply Code for Manufacturers FSCM is sho
255. 41T 8552B 8554B listed above except Span Width which should be 0 100 MHz should be compatible with Tracking Generator Recorder Strip Chart Compatible with Digital to Analog Converter Accuracy 0 5 of full scale Temperature Controlled Range 0 55 C Statham Chamber Model 325 Test Oscillator Range 10 Hz to 10 MHz HP 652A Output Impedance 60022 and 5022 Distortion 740 dB down Output Level gt 1 Vrms Test Oscillator Range 30 Hz 50 kHz HP 204D Level 71V into 6002 Distortion 60 dB low crossover distortion Tracking Generator Output to 0 dBm 5022 HP 8444A Flatness 0 5 dB Compatible with Spectrum Analyzer HP 141T 8552B 8554B HP 141T 8552B 8554B Tracking Generator Output to 0 dBm 50Q HP 8443B Compatible with Spectrum Analyzer HP 141T 8552B 8553B Variable Phase Range 20 Hz to 60 kHz HP 203A P A Oscillator Output Impedance 6009 Phase Variability 0 to 360 Distortion gt 64 dB down Variable Voltage Range 5 10 of nominal line volt GR W5MT3A Transformer age 100 120 220 or 240 volts For 120V range is 105 130 Vrms Metered Accuracy 1 Vrms Vector Voltmeter Range 1 550 MHz HP 8405A Sensitivity 20 uV Phase Range 18 full scale down to 6 full scale Phase Resolution 0 1 Phase Accuracy 1 5 Voltage Ratio Accuracy 0 2 dB P Performance A Adjustments T Troubleshooting Tracking Generator Output to 0 dBm 5022 HP 8444A P
256. 46 1220 0102 nd 8 ee Xm 1000 FECL 1 1000 EECL i 1000 T tio 0 01 0 0 O1UF ECL O lyr T gt CL a a i d Se NEN LL ELLA p hi EM bee Ono OG M mc MD c EE ae m E Sud EQ E 1 Figure 8 43 RE Dividers Schematic Diagram Figure 8 42 A10A2 RF Divider Assembly Component Locations 8 41 SERVICE SHEET 12 PRINCIPLES OF OPERATION General The A26A3 Modulator Assembly contains a current controlled attenuator which varies the RF output level The A26A4 AGC Amplifier controls the drive to the modulator Attenuation is determined by the OUTPUT LEVEL vernier and by the AM input signal when the AM switch is on or by the pulse input signals when AM is set to PULSE Modulator A26A3 The RF signal from the binary dividers is amplified by Modulator Preamplifier A26U2 The amplifier is a sealed microcircuit that plugs into the rear of the modulator board The amplifier drives the AUX RF OUT port through resistor RI and drives the modulator diodes Diodes through CR8 for a balanced resistive network in which the resistance is controlled by the current biasing them Capacitors C3 through C6 improve the modulator balance at high frequencies The control current comes from the AGC output amplifier through choke L2 and then splits between R4 to CR4 and R3 or R5 CR5 to CR8 and R2 The RF signal is coupled
257. 465A Capacitor 5 F 0180 2211 50 Ohm Load 11593A PROCEDURE 1 Connect equipment as shown Figure 4 8 with the generator connected to the rms voltmeter through the detector amplifier 15 kHz LPF and across the 50 ohm load Set Signal Generator s controls as follows 4 30 Model 8640B Option 004 PERFORMANCE TESTS Performance Tests 4 23 RESIDUAL AM TEST Cont d Meter Function ia 4 LEVEL COUNTER MODE EXPAND Off LOCK Off Source INT MODULATION MODULATION FREQUENCY 1 kHz RANGE 256 512 MHz FREQUENCY 500 MHz OUTPUT LEVEL Switches Woo sm 4 a x CFLS dBm OUTPUT LEVEL Vernier CAL RF ON OFF ON 2 Set Meter Function to AM and slowly turn Signal Generator s MODULATION control clockwise until its panel meter indicates 1076 AM Note voltmeter reading in dB 3 Set generator s AM switch to OFF The residual AM should read gt 58 dB below the reference noted in step 2 1 gt 78 dB down The 10 AM after detection is 20 dB below the carrier level Residual AM is then 20 dB 78 dB 58 dB 58 dB 4 Replace the 15 kHz LPF with the 3 kHz LPF Add the capacitor between amplifier and filter and repeat steps 1 through 3 The residual AM should read gt 65 dB below the reference noted in step 2 1 gt 85 dB down 65 dB 4 24 RESIDU
258. 480 28480 28480 28480 28480 28480 28480 24226 24226 28480 28480 28480 24546 24546 24546 16299 24546 24546 24546 24546 16299 24546 28480 28480 28480 28480 28480 28480 28480 28480 28480 24226 24226 28480 28480 28480 24546 24546 24546 16299 24546 24546 24546 24546 16299 24546 24546 24546 28480 28480 32997 32997 32997 32997 MFR PART NUMBER 08640 60024 0160 3456 0160 3456 0160 3878 0160 3456 0160 3456 0160 3878 0160 3456 0160 3873 0160 3876 10 221 10 221 1200 0173 1854 0247 1854 0247 C4 1 8 TO 909R F C3 1 8 TO 100R G C3 1 8 TO0 10R G C4 1 8 TO 348R F C3 1 8 TO 121R G C3 1 8 TO 316R G C4 1 8 TO 909R F C3 1 8 TO0 16R2 G C4 1 8 TO 348R F C3 1 8 TO 121R G 08640 00007 08640 60037 0160 3456 0160 3456 0160 3878 0160 3456 0160 3456 0160 3878 0160 3456 10 221 10 221 1200 0173 1854 0247 1854 0247 C4 1 8 TO 909R F C3 1 8 TO 100R G C3 1 8 TO0 10R G C4 1 8 TO 348R F C3 1 8 TO 147R G C3 1 8 TO 316R G C4 1 8 TO 909R F C3 1 8 TO0 16R2 G C4 1 8 TO 348R F C3 1 8 TO0 21R5 G C3 1 8 TO0 21R5 G C3 1 8 TO0 51R1 G 08640 00007 08640 60196 3006P 1 503 3006P 1 202 3006P 1 501 3006P 1 102 REPLACEABLE PARTS REFERENCE DESIGNATION A3A4R6 A3A4R7 A3A4R8 4 9 A3A4TP1 A3A4TP2 A3A4U1 4 4 1 A4C2 A4C3 A4C4 A4C5 AACRI BACR2 AAMPI 401 402 A403 A4R1 A4R2 A4R3 A4R4 A4R5
259. 56 512 MHz and tune to 550 MHz Counter should read 550 MHz on EXT 0 550 COUNTER MODE Tune frequency to approximately 345 MHz Slowly rotate FREQUENCY TUNE in a cw direction A faint but audible click should be heard when tuning through the range 355 357 MHz This is relay switching of the high band filters Meter and Modulation Oscillator Checks Refer to step 1 for initial control settings a Set FM to INT AM to AC MODULATION fully cw and Meter Function to AM Connect FM OUTPUT to AM INPUT through a BNC tee Connect an ac voltmeter to the tee Set AUDIO OUTPUT LEVEL to 0 707 Vrms as read on the voltmeter The generator s front panel meter should read between 9 6 and 10 4 Return AM to OFF Connect FM OUTPUT to COUNTER INPUT with COUNTER MODE set to EXT 0 10 and EXPAND XI 00 The counter should read between 980 and 1020 Hz for standard instruments or 970 and 1030 Hz for Option 001 Record this frequency for future reference 950 1020 Hz 970 1030 Hz Option 001 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 12 BASIC FUNCTIONAL CHECKS Cent d For Option 001 only set MODULATION FREQUENCY to and MODULATION FRE QUENCY vernier to 100 Change MODULATION FREQUENCY range as shown below The counter should read within the frequency limits indicated MODULATION FREQUENCY Range Frequency Limits Hz 90 110 900 1100 9 000 11 000 90 000 110 000 270 000 330 000 Outp
260. 58 8959 0757 0290 28480 5905 00 858 8826 0757 0461 28480 5905 00 089 7577 0757 0294 28480 5905 00 974 5709 0757 0462 28480 5905 00 493 0783 0757 0316 28480 5905 00 981 7475 0757 0464 28480 5905 00 420 7155 0757 0317 28480 5905 00 244 7189 0757 0465 28480 5905 00 904 4412 0757 0346 28480 5905 00 998 1906 0757 0472 28480 5905 00 257 9210 0757 0379 28480 5905 00 244 7190 0757 0934 28480 5905 00 102 8023 0757 0394 28480 5905 00 412 4036 0757 0984 28480 5905 00 221 8312 0757 0395 28480 5905 00 891 4210 0757 1094 28480 5905 00 917 0580 0757 0397 28480 5905 00 232 3125 0757 1100 28480 5905 00 917 0586 0757 0398 28480 5905 00 788 0291 0811 1553 28480 5905 00 139 9567 0757 0399 28480 5905 00 929 7774 0811 1662 28480 5905 00 475 8185 0757 0400 28480 5905 00 998 1902 0811 1666 28480 5905 00 402 7082 0757 0401 28480 5905 00 981 7529 08553 6012 28480 5950 00 138 1335 0757 0403 28480 5905 00 412 4023 08555 20093 28480 5999 00 008 8444 0757 0405 28480 5905 00 493 0738 08640 60004 28480 6625 00 528 8978 0757 0414 28480 5905 00 764 2021 08640 60005 28480 6625 00 521 2598 0757 0416 28480 5905 00 998 1795 08640 60007 28480 6625 00 521 2600 0757 0418 28480 5905 00 412 4037 08640 60014 28480 6625 00 521 2604 0757 0419 28480 5905 00 891 4213 08640 60016 28480 6625 00 521 2605 0757 0420 28480 5905 00 493 5404 08640 60022 28480 6625 00 521 2606 0757 0421 28480 5905 00 891 4219 08640 60028 28480 6625 00 521 2607 0757 0422 28480 5905 00 728 9980 08640 60163 28480 5961 00 577 0556
261. 5910 00 828 0808 5910 00 772 6726 5910 00 831 8690 5910 00 728 4974 5910 00 494 5056 5910 00 057 3934 5910 00 961 9591 5910 00 497 7598 5910 00 911 9271 5910 00 917 0668 5910 00 234 9817 5910 00 936 0577 5910 00 058 7916 5910 00 411 3606 5910 00 776 4174 5910 00 776 4176 5910 00 477 8013 5910 00 455 0119 5910 00 247 8593 TABLE 6 5 PART NUMBER NATIONAL STOCK NUMBER CROSS REFERENCE INDEX NATIONAL NATIONAL PART STOCK PART STOCK NUMBER FSCM NUMBER NUMBER FSCM NUMBER 0160 2055 28480 5910 00 211 1611 0160 3939 28480 5910 00 488 3049 0160 2152 28480 5910 00 410 9365 0160 3940 28480 5910 00 488 3054 0160 2199 28480 5910 00 244 7164 0160 3961 28480 5910 00 487 7558 0160 2204 28480 5910 00 463 5949 0180 0049 28480 5910 00 893 5179 0160 2207 28480 5910 00 430 5675 0180 0058 28480 5910 00 027 7069 0160 2228 28480 5910 00 719 9880 0180 0094 28480 5910 00 082 5119 0160 2236 28480 5910 00 444 6724 0180 0100 28480 5910 00 752 4172 0160 2260 28480 5910 00 789 6956 0180 0116 28480 5910 00 809 4701 0160 2261 28480 5910 00 430 5750 0180 0141 28480 5910 00 879 0123 0160 2262 28480 5910 00 887 9754 0180 0197 28480 5910 00 850 5355 0160 2263 28480 5910 00 401 7891 0180 0228 28480 5910 00 719 9907 0160 2265 28480 5910 00 444 6725 0180 0229 28480 5910 00 403 2449 0160 2266 28480 5910 00 430 5754 0180 0234 28480 5910 00 430 5953 0160 2276 28480 5910 00 469 2953 0180 0269 28480 5910 00 043 1396 0160 2306 2848
262. 5W F TUBULAR RESISTOR 121 OHM 2 05W F TUBULAR LOOP BUFFER INPUT COUNTER BUFFER AMPLIFIER ASSY CAPACITOR FXD 1000PF 10 1000WVDC CER CAPACITOR FXD 1000PF 10 1000WVDC CER CAPACITOR FXD 1000PF 20 100WVDC CER CAPACITOR FXD 1000PF 10 1000WVDC CER CAPACITOR FXD 1000PF 10 1000WVDC CER CAPACITOR FXD 1000PF 20 100WVDC CER CAPACITOR FXD 1000PF 10 1000WVDC CER COIL FXD MOLDED RF CHOKE 2 2UH 10 COIL FXD MOLDED RF CHOKE 2 2UH 10 INSULATION XSTR TO 5 075 THK TRANSISTOR NPN SI TO 39 PD 1W FT 800MHZ TRANSISTOR NPN SI TO 39 PD 1W FT 800MHZ RESISTOR 909 CHM 1 125W F TUBULAR RESISTOR 100 OHM 2 05W F TUBULAR RESISTOR 10 OHM 2 05W F TUBULAR RESISTOR 348 OHM 1 125W F TUBULAR RESSITOR 147 OHM 2 05W F TUBULAR RESISTOR 316 OHM 2 05W F TUBULAR RESISTOR 909 OHM 1 125W F TUBULAR RESISTOR 16 2 OHM 2 05W F TUBULAR RESISTOR 348 OHM 1 125W F TUBULAR RESSITOR 21 5 OHM 2 05W F TUBULAR RESISTOR 21 5 OHM 2 05W F TUBULAR RESISTOR 51 1 OHM 2 05W F TUBULAR LOOP BUFFER INPUT VARACTOR HEAD ASSY NFRF NSR PART OF A3A2 NSR PART OF A3A2 NSR PART OF A3A2 NSR PART OF A3A2 OSCILLATOR LOOP ASSY NRFR CONNECTOR BOARD ASSY NOT ASSIGNED NOT ASSIGNED RESISTOR VAR TRMR 50KOHM 10 C SIDE ADJ RESISTOR VAR TRMR 2KOHM 10 C SIDE ADJ RESISTOR VAR TRMR 500 OHM 10 C SIDE ADJ RESISTOR VAR TRMR 1KOHM 10 C SIDE ADJ NOT ASSIGNED REPLACEABLE PARTS MFR CODE 28480 28480 28480 28
263. 6 zb det 46 5 d k 1 2 Q 1820 066 MU R E m R cR V Vel m gua iv w CI n RISER ASSY COUNTLOCK TO TIME BASE DS RE Pig a 58 iene TIME BASE 19 200 TIME BASE VERNIER gt a 1 NC cl cla Y 3 LOCK EXP 100 iLi 21 Q EXP 1001 21 o LOCK NEN heu eoi cg us t DOT RM ERES 210 EXP 10 tU gt i i M 02 Le FOUNTEA TIME BASE iilii OPTION 122A EXP 10 1H PHASE LOCK TUNE ee ul PAR e acus REFERENCE DEMGHATIONS WITHIN DUTLIMED ARE ABBREVIATED FULL GESIGHATION CLUDES ASSEMBLY NUMBER ag OF AI 15 DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE 5 SH NN cua uU SERERE Ir ERATE D M ts STUN AE LOCK DECODER lt ac n 20 we BRE ie i ER 200 20V 1 2 lt 1000 JT 67 lt A 52v mr 9 5 2 service REFERENCE DESIGNATIONS 1 COD A CODES d LOW oL 1 PRFIHZ C1 6 8 34 40 CRI Yt DELETED ABA3CT NOIES copt4 1 7 5 8 TIME BASE DECIMAL P
264. 6 7363 2N5415 2735 5961 00 139 9588 901 0418 28480 5961 00 721 3615 2100 1758 28480 5905 00 228 5989 901 0518 28480 5961 00 430 6819 2100 1986 28480 5905 00 139 2306 901 0539 28480 5961 00 577 0558 2100 2061 28480 5905 00 105 1775 902 00 78189 5310 00 261 7352 2100 2413 28480 5905 00 138 5086 902 0025 28480 5961 00 914 3087 2100 2489 28480 5905 00 105 1774 902 0048 28480 5961 00 912 3099 2100 2514 28480 5905 00 828 5431 902 0049 28480 5961 00 911 9277 2100 2521 28480 5905 00 170 3842 902 0184 28480 5961 00 835 3237 2100 2633 28480 5905 00 476 5796 902 0202 28480 5961 00 873 0867 2100 3154 28480 5905 00 615 8111 902 0244 28080 5961 00 787 4343 2100 3216 28480 5905 01 020 9348 902 3005 28480 5961 00 577 0559 2100 3265 28480 5905 00 474 8813 902 3059 28480 5961 00 458 4506 2100 3325 28480 5905 01 037 1599 902 3070 28480 5961 00 931 6989 2101 10 00 78189 5940 00 155 7685 902 3094 28480 5961 00 493 5428 2110 0332 28480 5920 00 921 6502 902 3104 28480 5961 00 494 8988 2140 0016 28480 6240 00 060 2941 902 3139 28480 5961 00 494 4848 2140 0244 28480 6240 00 951 3376 902 3182 28480 5961 00 229 1966 2190 0014 28480 5310 00 522 9950 PART NUMBER 251 06 30 261 251 15 30 400 252 06 30 300 252 10 30 300 252 15 30 300 252 15 30 340 252 18 30 300 2950 0001 2950 0035 3 331272 0 3 332070 5 30D107G025DD2 30D506G025CC2 30D506G050DD2 30D906G016CC2 3006P 1 102 3006P 1 103 3006P 1 202 3006P 1 501 3100 3081 3
265. 6 PF 300V CAPACITOR FXD 56 PF 300V CAPACITOR FXD 56 PF 300V CAPACITOR FXD 56 PF 300V CAPACITOR FXD 100 PF 300V SELECTED COMPONENT CAPACITOR FX13 680 PF 300V SELECTED COMPONENT CAPACITOR FXD 1500 PF 300V SELECTED COMPONENT CAPACITOR FXD 100 PF 300V RESISTOR FXD 1K OHM RESISTOR FXD 1 78 OHM RESISTOR FXD 1 21 OHM RESISTOR FXD 511 OHM RESISTOR FXD 464 OHM RESISTOR FXD IK OHM RESISTOR FXD 2K OHM RESISTOR FXD 1 5K OHM RESISTOR FXD 6K OHM RESISTOR FXD 1 5K OHM RESISTOR FXD 3K OHM RESISTOR FXD 1 5K OHM RESISTOR FXD 3K OHM RESISTOR FXD IK OHM RESISTOR FXD 1 5K OHM RESISTOR FXD 3K OHM RESISTOR FXD 1 5K OHM RESISTOR FXD 3K OHM RESISTOR FXD 1 5K OHM RESISTOR FXD 16 2K OHM NSR INCLUDES PRINTED CIRCUIT TRACES AND ROTOR A9AIMP29 INTERCONNECT ASSEMBLY CONNECTOR PC EDGE LABEL BOARD CONNECTOR Model 8640B Option 004 08640 90073 CHANGE 7 Cont d A9A2WI 08640 60198 CABLE RIBBON 5 45 INCLUDES THE FOLLOWING ITEMS 1251 2615 CONNECTOR RIBBON CBL 2 EACH 81201711 CABLE 16 COND 28 GAUGE A9A2W2 08640 60199 CABLE RIBBON 7 50 1NCLUDESTHE FOLLOWING ITEMS 1251 2615 CONNECTOR RIBBON CBL 2 EACH 8120 1711 CABLE 16 COND 28 GAUGE 9 2 1 08640 60255 INTERCONNECT BOARD ASSEMBLY INCLUDES A9A2WI and A9A2W2 9 2 111 1250 0507 SOCKET DIP16 PIN A9A2A1J2 1250 0507 SOCKET DIP16 PIN A9A2AIPI 1251 1626 CONNECTOR PC 24 CONT A9A2A1P2 1251 0472 CONNECTOR PC 12 CONT and 6 41 Table 6 3 Change MP29 to 1500 043
266. 60 3094 0160 3094 MODEL 8640B OPTION 004 REFERENCE HP PART DESIGNATION NUMBER A8A3C6 0160 3094 A8A3C7 A8A3C8 0160 2055 A8A3C9 0160 2055 A8A3C10 0160 2055 11 0160 2055 A8A3C12 0160 2055 A8A3C13 0160 2055 A8A3C14 0160 3094 A8A3C15 0160 3879 A8A3C16 0160 2055 A8A3C17 0160 3094 A8A3C18 0160 2055 A8A3C19 0160 3879 A8A3C20 0160 3879 A8A3C21 0160 3877 A8A3C22 0160 3877 A8A3C23 0160 3457 A8A3C24 0160 3456 A8A3C25 0160 3094 A8A3C26 0160 2055 A8A3C27 0180 0197 A8A3C28 0180 0197 A8A3C29 0180 0197 A8A3C30 0180 0197 A8A3C31 0180 0197 A8A3C32 0160 3094 A8A3C33 0160 2055 A8A3C34 0180 0197 A8A3C35 0180 0197 A8A3C36 0180 0197 A8A3C37 0180 0197 A8A3C38 0160 2055 A8A3C39 0180 0197 A8A3C40 0160 3456 A8A3CR1 1901 0040 A8A3J1 1250 1383 A8A3L1 9140 0137 A8A3L2 9140 0137 A8A3L3 9140 0137 A8A3L4 9140 0137 A8A3L5 9140 0137 A8A3L6 9140 0137 A8A3L7 9140 0137 A8A3L8 9140 0137 A8A3L9 9140 0137 A8A3L10 08640 80001 A8A3L11 9140 0137 A8A3L12 08640 80001 A8A3L13 08640 80001 A8A3L14 08640 80001 A8A3MP1 2190 0003 A8A3MP2 2200 0155 A8A3MP3 2260 0001 A8A3MP4 08640 20211 A8A3MP5 08640 40040 A8A3Q1 1854 0019 A8A3Q2 1854 0019 A8A3R1 0698 3155 A8A3R2 0757 0274 A8A3R3 0757 0442 A8A3R4 0757 0438 A8A3R5 0698 7229 A8A3R6 0757 0416 A8A3R7 0757 0442 A8A3R8 0757 0442 A8A3R9 0698 0085 A8A3R10 0757 0279 A8A3R11 0757 0416 A8A3R12 0757 0416 A8A3R13 0757 0438 A8A3R14 0757 0438 A8A3R15 0757 0438 QTY 10 TABLE 6 3 REPLACEABLE PARTS
267. 6289 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 REPLACEABLE PARTS MFR PART NUMBER 08640 20200 08640 20214 08640 20219 08640 40004 08640 20064 2200 0105 08640 20133 3030 0007 2200 0145 08640 20206 5133 12 S MD R C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F 08640 60106 08640 60106 08640 60106 08640 60106 08640 60106 08640 60106 8120 1830 8120 1832 8120 1831 252 15 30 300 252 18 30 300 08640 60023 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 2055 0160 2055 0160 3456 0160 2055 0160 3456 0160 3456 0160 3456 150D475X9035B2 0160 3456 150D475X9035B2 150D225X9020A2 150D106X9020B2 150D104X9035A2 150D106X9020B2 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 3456 0160 2055 0160 2055 0160 2055 0160 2055 0160 2055 MODEL 8640B OPTION 004 REFERENCE HP PART DESIGNATION NUMBER 10 2 41 0160 2055 A10A2C42 0180 1743 A10A2C43 0180 1743 A10A2C44 0180 1743 A10A2C45 0180 1743 A10A2C46 0180 1743 A10A2C47 0180 1743 10 2 48 0180 1743 A10A2C49 0180 1743 A10A2C50 0180 1743 A10A2C51 0160 3456 A10A2C52 0180 0197 A10A2C53 0180 0197 A10A2C54 0160 3456 10 2 1 1901 0025 A10A2CR2 19
268. 71 5962 00 513 2691 5962 01 006 0177 5962 00 628 8129 5962 01 006 8383 5962 00 247 9568 5961 00 765 6071 5961 00 904 2540 5961 00 193 4463 5961 00 987 4700 5961 00 111 0455 5961 00 138 7314 5961 00 139 9588 5961 00 162 9698 5961 00 990 5369 5961 00 917 0660 5961 00 998 1923 5961 00 985 9074 5961 00 137 4608 5961 00 836 1887 5961 00 229 1963 TABLE 6 5 PART NUMBER NATIONAL STOCK NUMBER CROSS REFERENCE INDEX NATIONAL NATIONAL PART STOCK PART STOCK NUMBER FSCM NUMBER NUMBER FSCM NUMBER 854 0247 28480 5961 00 464 4049 902 3234 28480 5961 00 491 6606 854 0250 28480 5961 00 577 0557 902 3256 28480 5961 00 412 0957 854 0345 28480 5961 00 401 0507 902 3345 28480 5961 00 412 0959 854 0351 28480 5961 00 892 8706 906 00 78189 5310 00 754 4399 854 0404 28480 5961 00 408 9807 910 0016 28480 5961 00 954 9182 855 0020 28480 5961 00 105 8867 910 0022 28480 5961 00 690 9341 855 0049 28480 5961 00 520 5000 920 02 78189 5310 00 262 0359 855 0062 28480 5961 00 222 6451 924 02 78189 5310 00 596 7681 901 0022 28480 5961 00 071 5271 990 0326 28480 5961 00 513 2831 901 0025 28480 5961 00 978 7468 2N3053 4713 5961 00 985 9073 901 0033 28480 5961 00 821 0710 2N3251 4713 5961 00 760 0960 901 0040 28480 5961 00 965 5917 2N3528 2735 5961 00 945 3380 901 0049 28480 5961 00 911 9275 2N3738 4713 5961 00 850 8921 901 0050 28480 5961 00 914 7496 2N5179 4713 5961 00 401 0507 901 0159 28480 5961 00 49
269. 72 22 Power Cables Available 1 252 4 26 Pulse Modulation Test Setup 4 74 Preparation for Rack Mounting 2 4 4 27 Pulse Measurements 4 28 3 dB Bandwidth Test Setup 4 78 ELI Lamp Replacement e l1 3 1 Distortion Test Setup Front Panel Controls Indicators and 4 30 IFM Sensitivity and Accuracy Test Setup connectors s 132 4 31 Incidental AM Test Setup m oues 32 Counter External Sensitivity Test Setup 4 3 3 Internal AC DC Switch 3 6 1 35 1 Sensitivity Test Setup Ber z Rear Panel 2 Connectors BA 4 33 Internal Reference Accuracy Test Setup 4 88 gt _Pperator s adds C33 4 34 Internal Reference Drift Rate Stability 3 6 Setting the Frequency and Ampli Test Setu Controls x 37 Setting the Modulation Controls 3 16 L _ RF Detector Offset Adjustment Test 4 11 Frequency Stability vs Time and Restabiliza Setup ur on Time Test Setup 5 2 Output Level Yemler and Meter Frequency Stability vs Temperature Test Setup Test Setup 4 18 Preliminary AM Adjustments Cr Frequency Stability vs Line Voltage a AM Accuracy Adjustment Test Setup Test setup 5 5 WT Pot Adjustment 5 24 Frequency Stability vs Lond Level and Location of RF Oscillator Stop Adjustments Mode Test Setup Shown in Maximum ccw Position 45 SubHamonics and Non Harmonic View with Instr
270. 79 1 0370 2380 1 0370 2381 1 0370 2382 1 0370 2623 1 0370 2387 1 0370 0623 1 0370 2446 1 0403 0026 0590 1011 1 1400 0825 1 1540 0034 1 08640 201631 3150 0203 1 5001 0135 1 5060 0109 1 08640 000661 08640 000211 08640 4044 1 08640 000221 08640 000301 08640 00058 08640 000591 08640 200781 08640 200791 08640 200851 08640 202041 08640 400161 08640 400461 08640 400471 08640 400491 08640 400511 TABLE 6 3 DESCRIPTION REPLACEABLE PARTS CHASSIS PARTS CAPACITOR FXD 390 OUF 75 10 50VDC AL CAPACITOR FXD 39000 75 10 50VDC AL CAPACITOR FXD 3900UF 75 10 75VOC AL CAPACITOR FXD 82000 75 10 25VDC AL CAPACITOR FXC 82000 75 10 25VDC CAPACITOR FXD 022UF 20 250WVAC MET LAMP GLOW BULB T 2 105V FUSE FOR FUSE FOR 2A 250V 100 120V OPERATION 1 25A 250V 220 240V OPERATION RF OUTPUT NSR P O W4 NSR P O W12 NOT ASSIGNED NSR P O W14 SEE FIGURE 6 2 NSR NSR P O W15 P O W17 METER TERMINAL SLDR LUG 10 SCR 204 094 INSULATOR COVER TO 3 KNOB BAR SKIRTED 0 250 FREQUENCY RANGE KNOB RIND CONCENTRIC 0 125 FM KNOB AM KNOB BAR BASE 0 250 DIA SHAFT PEAK DEVIATION RANGE KNOB BAR BASE 0 250 DIA SHAFT 33 THK DIA SHAFT DIA SHAFT RND CONCETRAIC 0 125 DIA SHAFT KNOB RND SKIRTED 0 250 DIA SHAFT STANDARD MOD FREQUENCY KNOB BASE PTR 375 JGK MGP FINE TUNE KNOB BASE 0 250 DIA SHAFT STANDARD AUD CUT IV KNO
271. 80 28480 71785 71785 26742 28480 56289 28480 56289 28480 56289 284480 28480 28480 19701 19701 19701 24546 24546 32997 24546 32997 16299 32997 REPLACEABLE PARTS MFR PART NUMBER C4 1 8 T0 422R F C4 1 8 T0 3161 F C4 1 8 T0 5111 F C4 1 8 T0 1003 F C4 1 8 T0 1003 F C4 1 8 TO 1961 F C4 1 8 T0 3831 F C4 1 8 T0 1001 F C4 1 8 T0 10R0 F C4 1 8 T0 1003 F C4 1 8 T0 1003 F C4 1 8 TO 1961 F C4 1 8 T0 4222 F C4 1 8 T0 1002 F C4 1 8 T0 4221 F C4 1 8 TO 101 F MF4C1 8 T0 1332 F C4 1 8 T0 2371 F C4 1 8 T0 1333 F C4 1 8 T0 1001 F C4 1 8 T0 1781 F C4 1 8 T0 825R F C4 1 8 T0 1001 F C4 1 8 T0 1002 F C4 1 8 T0 825R F 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 MC7812CP LM311H SN7402N SN7406N SZ 10939 182 SZ 10939 230 08640 60068 1251 3231 08640 60067 252 15 30 340 252 15 30 340 91 6915 0702 00 08640 60069 150D685X9035B2 0160 2055 150D685X9035B2 0160 2055 150D685X9035B2 0160 2055 4040 0749 4040 0754 MFC1 2 TO 178R F MF7C1 2 TO 178R F ET50X102 C4 1 8 T0 1002 F C4 1 8 T0 1001 F 3006P 1 103 C4 1 8 T0 7501 F 3006P 1 103 C4 1 8 T0 4222 F 3006P 1 202 MODEL 8640B OPTION 004 REFERENCE DESIGNATION A26A8R11 A26A8R12 A26A8R13 A26A8R14 A26A8R15 A26A8S1 A26A8TP1 A26A8TP2 A26A8TP3 A26A8U1 A26A8U2 A26A8VR1 A26A8VR2 HP PART NUMBER QTY 0757 0441 0757 0462 0757 0418 0757 0462 2100 3054 3
272. 80 00000 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 04713 28480 28480 07263 28480 04713 28480 28480 28480 28480 28480 78189 01295 28480 04713 28480 28480 28480 28480 28480 78189 16299 24546 24546 19701 24546 16299 19701 32997 16299 24546 16299 19701 24546 24546 16299 24546 16299 16299 24546 24546 03888 32997 24546 24546 24546 24546 24546 16299 24546 MFR PART NUMBER 1901 0025 1901 0025 1901 0025 1901 0025 1901 0050 1901 0050 1901 0050 1901 0025 0490 1078 4040 0750 OBD 4040 0756 OBD 1854 0221 1854 0221 1854 0404 1854 0404 1853 0038 1205 0011 1200 0173 1853 0038 1205 0011 1200 0173 1853 0038 1200 0173 2N3053 1200 0173 1205 0011 517843 1200 0173 243738 0510 0002 1205 0085 2360 0199 2420 0003 2190 0018 1906 00 2N2904A 1200 0173 2N3738 0510 0002 1205 0085 2360 0199 2420 0003 2190 0018 1906 00 C4 1 8 T0 4642 F C5 1 4 TO 31R6 F C4 1 8 TO 121R F 4 1 8 0 6191 C4 1 8 TO 1331 F C4 1 8 TO 2610 F MF7C1 2 T0 3161 F 3006P 1 100 C4 1 8 TO 2611 F C4 1 8 TO 1331 F C4 1 8 TO 2610 F 4 1 8 0 6191 C5 1 4 TO 31R6 F C4 1 8 TO 121R F C4 1 8 T0 4642 F C4 1 8 TO 101 F C4 1 8 TO 383R F C4 1 8 TO 2610 F C4 1 8 TO 101 F C4 1 8 T0 1080 F PME55 1 8 TO 21R5 F 3006 02 C4 1 8 TO 1001 F C4 1 8 TO 1001 F C4 1 8 TO 10R0 F C4 1 8 TO 8251 F C4 1 8 TO 7501 F C4 1 8 TO 1102
273. 8480 28480 28480 28480 28480 28480 28480 28480 95987 78189 28480 28480 28480 00000 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 16299 24546 28480 16299 REPLACEABLE PARTS MFR PART NUMBER 08640 60019 2112 MODIFIED 0160 2257 0160 2261 DM19F202F0300WV1CR DM19F202F0300WV1CR 0160 2055 DV11PR18A 150D106X9020B2 0160 2204 0160 2199 150D685X9035B2 150D685X9035B2 1500337 900652 1500337 900652 150D685X9035B2 150D685X9035B2 150D226X9015B2 0160 2261 0160 2236 150D107X9010R2 150D107X9010R2 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 1901 0040 0340 0037 0340 0039 0340 0037 0340 0039 1430 0764 08640 00006 08640 20090 08640 00008 08640 20062 2200 0103 N 632 3 8 SF 1904 00 2260 0009 0403 0026 4040 0749 OBD 08640 20090 08640 20090 08640 20090 08640 00081 1853 0050 1854 0071 1853 0276 1200 0173 1854 0351 1854 0003 1854 0003 1200 0173 1854 0351 1853 0276 1854 0071 1853 0020 1855 0062 1854 0071 0698 8294 C4 1 8 TO 1963 F C4 1 8 TO 7872 F 0698 8294 C4 1 8 TO 1333 F MODEL 8640B OPTION 004 REFERENCE HP PART QTY DESIGNATION NUMBER 11 6 0757 0472 1 Al1RT7 0757 0401 8 Al1R8 0757 0401 11 9 0757 0441 1 A11R10 0757 0447 1 11 11 0757 0199 5 11 12 0757 0442 6 11 13 0757 0279 2 11 14 0757 0199 11
274. 9 0698 7277 0757 0 0757 0 0757 0 0757 0 0757 0 0757 0 23 58 59 80 98 99 0757 0200 0757 0274 0757 0278 0757 0279 5 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28780 28480 28780 28480 28480 28480 28480 28480 58480 28480 28480 28480 28480 28480 28480 28480 8480 28480 28480 28480 28480 28480 NATIONAL STOCK NUMBER 5905 00 974 6080 5905 00 407 0059 5905 00 828 0377 5905 00 489 6773 5905 00 194 0341 5905 00 974 6079 5905 00 493 4289 5905 00 974 6083 5905 00 828 0404 5905 00 828 0397 5905 00 826 3262 5905 00 405 3677 5905 00 078 1548 5905 00 974 6077 5905 00 491 4586 5905 00 489 2047 5905 00 138 5053 5905 00 126 1711 5905 00 407 0114 5905 00 138 7305 5905 01 009 7560 5905 00 161 9026 5905 00 954 8684 5905 00 430 6204 5905 00 830 6677 5905 00 972 4907 5905 00 830 6188 5905 00 981 7513 5905 00 891 4224 5905 00 858 9105 5905 00 110 0851 5905 00 221 8310 TABLE 6 5 PART NUMBER NATIONAL STOCK NUMBER CROSS REFERENCE INDEX NATIONAL NATIONAL PART STOCK PART STOCK NUMBER FSCM NUMBER NUMBER FSCM NUMBER 0757 0280 28480 5905 00 853 8190 0757 0447 28480 5905 00 981 7530 0757 0288 28480 5905 00 193 4318 0757 0458 28480 5905 00 494 4628 0757 0289 28480 5905 00 998 1908 0757 0460 28480 5905 00 8
275. 9 RF FILTER ADJUSTMENT REFERENCE Service Sheet 10 DESCRIPTION A spectrum analyzer and a tracking generator are used to measure the insertion loss and frequency response of each of the RF filters Those filters that are adjustable are adjusted if necessary A frequency counter connected to the tracking generator s auxiliary output is used to accurately set the analyzer s frequency This procedure should be performed only when the RF filters have been repaired or are suspect The filters must meet specified pass band and stop band characteristics Figure 5 8 illustrates the terms used in the procedure MAXIMUM PASS BAND LOSS PASS BAND STOP BAND REFERENCE FREQUENCY FREQUENCY LEVEL SS 7 BAND LOSS 2 BAND 9 5 5 TYPICAL z CHEBYCHEV FILTER RESPONSE N AD TN TYPICAL ae 7 ELLIPTICAL 2 FILTER FREQUENCY MHz RESPONSE Figure 5 8 Filter Terminology 5 29 Adjustments 5 39 RF FILTER ADJUSTMENT Cont d FREQUENCY COUNTER 502 INPUT TRACKING GENERATOR AUXILIARY OUTPUT RF OUTPUT ADJUSTMENTS TEST CABLE Model 8640B Option 004 MODEL 86408 OPTION 004 0 6 6 0 0709 FILTER OUT A10A1J4 FILTER IN A10A1J1 STEP 4 STEP 4 ADAPTER STEP 1 Figure 5 9 RF Filter Adjustment Test Setup EQUIPMENT Spectrum Analyzer Tracking Generator Frequency Counter Test Cable 2 required Adapter PROCEDURE HP 141T 8552B 8554B
276. 9 1500105 9035 2 A26A2C5 0160 3450 2 CAPACITOR FXD 5000PF 10 250WVDC 28480 0160 3450 A26A2C6 0160 0161 2 CAPACITOR FXD 01UF 10 200WVDC POLYE 56289 292P10392 A26A2C7 0160 3450 CAPACITOR FXD 5000PF 10 250WVDC 28480 0160 3450 A26A2C8 0180 1743 CAPACITOR FXD 10 10 35VDC TA SOLID 56289 150D104X9035A2 A26A2C9 NOT ASSIGNED A26A2C10 0180 0100 CAPACITOR FXD 4 77UF 10 35VDC TA 56289 150D475X9035B2 A26A2C11 0180 0116 CAPACITOR FXD 6 8UF 10 35VDC TA 56289 150D685X9035B2 A26A2C12 0180 0291 CAPACITOR FXD 10 10 35VDC TA SOLID 56289 1500105 9035 2 26 2 1 1910 0022 5 DIODE SWITCHING 3 5NS 5V 60MA 28480 1910 0022 A26A2CR2 1901 0022 DIODE STABISTOR 10V 250MA 28480 1901 0022 A26A2CR3 1901 0022 DIODE STABISTOR 10V 250MA 28480 1901 0022 A26A2CR4 1901 0022 DIODE STABISTOR 10V 250MA 28480 1901 0022 A26A2CR5 1901 0040 DIODE SWITCHING 2NS 30V 50MA 28480 1901 0040 A26A2CR6 NOT ASSIGNED A26A2CR7 1901 0040 DIODE SWITCHING 2NS 30V 50MA 28480 1901 0040 A26A2CR8 NOT ASSIGNED A26A2CR9 1910 0016 DIODE SWITCHING GE 60V VRM 60 MA 28480 1910 0016 A26A2CR10 1901 0040 DIODE SWITCHING 2NS 30V 50MA 28480 1901 0040 A26A2CR11 1901 0040 DIODE SWITCHING 2NS 30V 50MA 28480 1901 0040 A26A2CR12 1901 0040 DIODE SWITCHING 2NS 30V 50MA 28480 1901 0040 A26A2CR13 1901 0539 DIODE SCHOTTKY 28480 1901 0539 A26A2CR14 1910 0022 DIODE SWITCHING 3 5NS 5V 60MA 28480 1910 0022 A26A2CR15 1910 0022 DIODE SWITCHING 3 5NS 5V 60MA 28480 1910 0022 A26A2CR16 1910 0022 DIODE SWITCH
277. 944 5935 00 488 9782 5935 00 068 3546 5935 00 434 3040 5935 00 236 7955 5935 00 446 8768 5935 00 267 2973 5935 00 104 1184 6625 00 760 9521 5910 00 839 3940 5910 00 104 0144 5910 00 936 1522 5910 00 235 2356 5910 00 908 0402 5910 00 840 3042 5910 00 177 2581 5910 00 816 9485 5910 00 807 7253 5910 00 945 9849 5910 00 722 4117 5910 00 878 6691 5910 00 177 4300 5910 00 879 7313 5910 00 104 0145 5962 00 138 5248 5962 00 493 5961 NUMBER 820 0 820 0 820 0 820 0 820 0 820 0 820 0077 02 25 43 58 74 75 820 0205 820 0223 820 0328 820 0535 820 0557 820 0736 820 0753 820 0982 820 1003 826 0013 853 0007 853 0020 853 0027 853 0034 853 0038 853 0050 853 0224 853 0276 854 0003 854 0022 854 0023 854 0063 854 0071 854 0221 854 0232 FSCM 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 NATIONAL STOCK NUMBER 5962 00 138 5250 5962 00 450 8830 5962 00 252 4921 5962 00 117 8726 5962 00 405 3777 5962 00 404 2559 5962 00 229 8500 5962 00 170 9478 5962 00 614 5251 5962 00 009 1356 5962 00 788 0298 5962 00 189 02
278. 9A1 NSR NSR P O 19 1 P O 19 1 BOARD ASSY RF VERNIER RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 750 OHM 1 125W F TUBULAR 3 16K 1 125W F TUBULAR 2 37K 1 125W F TUBULAR 10K 1 125W F TUBULAR 28 7K 1 125W F TUBULAR RESISTOR 1K 1 125W RESISTOR VAR TRMR RESISTOR VAR TRMR RESISTOR 422 OHM 1 F TUBULAR 2KOHM 10 C 2KOHM 10 C 125W F TUBULAR TERMINAL TERMINAL SLDR STUD SLDR STUD REGULATOR ASSY 5 2V amp 44 6V MFR CODE 28480 28480 28480 28480 28480 28480 28480 24546 32997 24546 01121 24546 16299 24546 16299 91637 24546 24546 24546 16299 19701 24546 75042 16299 16299 24546 28480 28480 28480 28480 28480 28480 15818 04713 04713 28480 00779 00779 28480 28480 76854 76854 28480 28480 28480 28480 28480 28480 28480 28480 24546 24546 16299 24546 16299 24546 19701 19701 16299 28480 28480 28480 REPLACEABLE PARTS MFR PART NUMBER 1853 0050 1853 0050 1853 0027 1200 0173 1853 0050 1853 0027 1200 0173 C4 1 8 TO 1331 F 3006P 1 501 C4 1 8 TO 1781 F CB47G5 C4 1 8 TO 751 F C4 1 8 TO 196R F C4 1 8 TO 751 F C4 1 8 TO 3832 F RS1 2 T2 1R0 J C4 1 8 TO 42R2 F C4 1 8 TO 1331 F C4 1 8 TO 68R1 F C4 1 8 TO 422R F MF4C1 8 TO 6191 F C4 1 8 TO 1002 F BWH2 11 16 J C4 1 8 TO 147R F C4 1 8 TO 147R F C3 1 8 TO 2611 G 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 723B
279. A 30V 50MA 250MA 10 195 195 195 10V 250MA 60V 60MA 60V 60MA 60V 60MA 250MA 2NS 10 30V 50MA 250MA 2NS 30V 50MA 25A 150V CONT 5V COIL D RF CHOKE 240UH 5 D RF CHOKE 240UH 5 BROWN LG GREEN LG UAL 200 HFE 10MV VBE I PD 300MW FT 200MHZ N3251 SI CHIP UAL 200 HFE 10MV VBE I CHIP TO 18 PD 360MW I PD 300MW FT 200MHZ CHIP TO 18 PC 360MW I PD 300MW FT 200MHZ I PD 300MW FT 200MHZ RESISTOR VAR TRMP 5KOHM 10 C RESISTOR VAR TRMP 2KOHM 10 C RESISTOR 100 OHM 1 125W F TUBULAR RESISTOR 6 19K 1 RESISTOR 6 19K 1 RESISTOR 7 5K RESISTOR 1 1K RESISTOR 7 5K RESISTOR 100K RESISTOR 10K 1 de oe oe ge RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 10K 1 VAR T 14 7K 1 10K 1 14 7K 1 RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 5 11K 1 196K 1 3 83K 90 9K 5 11K PRR RESISTOR 5 11K RESISTOR 1 78K RESISTOR 6 19K 1 5 m oe RESISTOR 1 96K RESISTOR 51 1K PRR de oe ge RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 5 11K 51 1K 4 22K 10K 1 8 25K 1 PRR de oe ge 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR RMR 20KOHM 10 C 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR de oe ge 125W F TUBULAR 25W F TUBULAR 125W F TUBULAR 125W F T
280. A I 157K 2 15K 1 6 6 74 i proms MODULATION OSCILLATOR amma OSC BUFFER m see ee a o ww T kriz o 1 1 1 I 13 8V 1 272 62 14 44 30 v 0 13 8V is RD m i 2 P 2610 osc Ul CREN 1826 0007 R6 e 6 4 1000 UN Sa I 13 0071 i T e 6 5 gt 0 3 70 Fog osc Rll LEVEL 5110 INT FM BUFFER smem i Component Locations for A13 Assembly are on Service Sheet 25 20V F 13 8V i siio di R17 1 A RM E 2610 i R21 2610 20VtF Ai ye NT AM BUFFER 13 8V bb R18 1 i Fog re te 100 N Na TU 1854 0003 R22 2610 REFERENCE DESIGNATIONS WITHIN OUTLINED 20V F ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN 0 5 ASSEMBLY NUMBER e g RI OF ASSEMBLY AT 15 AIRI DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS SHOWN Al1 A13 FIXED FREQUENCY MODULATION OSCILLATOR 86408 OPTION 004 1323A Figure 8 35 Fixed Frequency Modulation Oscillator Schematic Diagram 8 35 SERVICE SHEET 9A PRINCIPLES OF OPERATION General When either the AM or FM modulation select switch is set to INT the Modulation Oscillator is enabled The oscillator feeds a signal with a frequency selected by the MODULATION FREQUENCY switch into the AM or FM modulator circuits and to the AM or FM front pa
281. A SOLID 56289 150D156X9020B2 A2C3 0160 2199 4 CAPACITOR FXD 30 PF 5 300 WCDV MICA 28480 0160 2199 2 4 0180 1746 CAPACITOR FXD 150 10 20VDC TA SOLID 56289 150D156X9020B2 A2C5 0180 2207 1 CAPACITOR FXD 1000 10 10VDC 56289 150D107X9010R2 A2CR1 1901 0040 30 DIODE SWITCHING 2NS 30V 50MA 28480 1901 0040 A2MP1 4040 0749 4 EXTRACTOR PC BOARD BROWN 28480 4040 0749 1480 0073 15 PIN DRIVE 0 250 LG 00000 OBD A2R1 NOT ASSIGNED A2R2 0698 3160 ESSITOR 31 6K 1 125W F TUBULAR 16299 C4 1 8 T0 3162 F A2R3 0698 3160 RESISTOR 31 6K 1 125W F TUBULAR 16299 C4 1 8 T0 3162 F A2R4 0757 0442 38 RESISTOR 10K 1 125W F TUBULAR 24546 C4 1 8 T0 1002 F A2R5 2100 2633 2 REISISTOR VAR TRMR 1050HM 10 C 19701 50 102 2 6 0698 3440 7 RESISTOR 196 OHM 1 125W F TUBULAR 16299 C4 1 8 T0 196R F A2R7 0698 3460 1 RESISTOR 422K 1 125W F TUBULAR 19701 MF4C1 8 T0 4223 F A2R8 0757 0279 9 RESISTOR 3 1K 1 125W F TUBULAR 24546 C4 1 8 T0 3161 F A2R9 0757 0420 10 RESISTOR 750 OHM 1 125W F TUBULAR 24546 C4 1 8 T0 751 F A2R10 0698 3157 3 RESISTOR 19 6K 1 125W F TUBULAR 16299 C4 1 8 T0 1962 F A2R11 0757 0398 RESISTOR 75 OHM 1 125W TUBULAR 24546 C4 1 8 T0 75RO0 F A2S1 3101 1728 1 SWITCH PH 5 CPDT 28480 3101 1728 2 0360 1514 88 TERMINAL SLDR STUD 28480 0360 1514 A2TP2 0360 1514 TERMINAL SLDR STUD 28480 0360 1514 A2TP3 0360 1514 TERMINAL SLDR STUD 28480 0360 1514 2 4 0360 1514 TERMINAL SLDR STUD 28480 0360 1514
282. ACITOR FXD 2 20 10 20VDC CAPACITOR FXD 47UF 80 20 25WVDC CER CAPACITOR FXD 2 20 10 20VDC CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 5500 PF 0 200WWDC CER CAPACITOR FXD 5500PF 0 200WVDC CER CAPACITOR FXD 5500PF 0 200WVDC CER CONNECTOR RF SMC M PC CONNECTOR RF SMC M PC CONNECTOR RF SMC M PC CONNECTOR RF SMC M PC RELAY REED A1 25A 120V CONT 4 5V COIL RELAY REED A1 25A 120V CONT 4 5V COIL RELAY REED A1 25A 120V CONT 4 5V COIL RELAY REED 1A 25A 120V CONT 4 5V COIL COIL PXD MOLDED RF CHOKE 462UH 5 COIL FXD MOLDED RF CHOKE 5UH 5 COIL FXD MOLDED RF CHOKE 462UH 5 COIL FXD MOLDED RF CHOKE 3UH 5 COIL FXD MOLDED RF CHOKE 32UH 5 COIL FXD MOLDED RF CHOKE 3UH 5 COIL FXD MOLDED RF CHOKE 8UH 5 COIL FXD MOLDED RF CHOKE 000004UH COIL FXD MOLDED RF CHOKE 4 74UH 5 COIL FXD MOLDED RF CHOKE 924UH 5 COIL FXD MOLDED RF CHOKE 000001UH COIL FXD MOLDED RF CHOKE 924UH 5 COIL FXD MOLDED RF CHOKE 6UH 5 COIL FXD MOLDED RF CHOKE 646UH 5 COIL FXD MOLDED RF CHOKE 6UH 5 COIL FXD MOLDED RF CHOKE 000004UH COIL FXD MOLDED RF CHOKE 000002UH COIL FXD MOLDED RF CHOKE 2 37UH 5 COIL FXD MOLDED RF CHOKE 231UH 5 COIL FXD MOLDED RF CHOKE 25UH 5 COIL FXD MOLDED RF CHOKE 231UH 5 COIL FXD MOLDED RF CHOKE 15UH 5 COIL FXD MOLDED RF CHOKE 162UH 5 COIL FXD MOLDED RF CHOKE 159UH 5 COIL FXD MOLDED RF CHOKE 00000
283. ACTOR ES 20v C2 ina R66 100 100 75 2 CR21 l 4 m 20V R15 1 51 1K VARACTOR CATHODE VARACTOR ANODE 2 Y 13 6 TO 16V Figure 8 29 FM Shaping Circuits and Phase Lock Loop Filter Schematic Diagram 8 31 SERVICE SHEET 8 PRINCIPLES OF OPERATION Over Deviation Detector A7 If the FM input signal is too large for the FM circuits to operate properly the Over Deviation Detector lights the REDUCE VERNIER annunciator lamp A6DSI Integrated circuit U2 is a dual comparator amplifier with wired OR outputs Pin 7 of U2B is at 1 1 pin 4 of U2A is at 1 1 Vdc these two voltages are the high and low reference voltages Pins 6 and 3 of U2 are the common inputs If the input which comes from the FM buffer amplifier is not between 1 1 and 1 1V the outputs go high gt IV Integrated circuit U3 is a hex inverter with open collector outputs U3A inverts the comparator output When U3A goes low capacitor C13 is discharged when U3A goes high again C13 slowly charges through R76 This effectively increases the duration of the comparator output when overloading occurs only for short periods U3B inverts the output of U3A and drives four parallel inverters U3C to U3F When the outputs of the four parallel inverters are low the display lamp turns on which occurs whenever the input to U3B is low Peak Deviation Switch A9 The Meter Attenuator scales the FM input signal to give the correct readi
284. AL FM TEST SPECIFICATION Residual FM Averaged rms CW and up to 1 8 maximum Post detection Noise Up to maximum allowable allowable peak deviation Peak deviation 300 Hz 20 Hz 300 Hz 20 Hz to to to to Bandwidth 3 kHz 15 kHz 3 kHz 15 kHz MHz 4 81 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 24 RESIDUAL FM TEST Cent d DESCRIPTION An FM discriminator is used to measure FM deviation a reference signal generator and a mixer are used to down convert the test Signal Generator s RF output to within the range of the discriminator The discriminator output is filtered and amplified and then measured with a voltmeter The voltmeter reading in mVrms is proportional to the rms frequency deviation of the residual FM See Table 4 1 Recommended Test Abridgements NOTE This test measures the total residual FM of both generators Therefore the reference generator must have residual FM that is less than or equal to the specification for the test generator REFERENCE SIGNAL GENERATOR FM 40 dB DISCRIMINATOR AMPLIEIER Be STEP 5 i T 15 kHz LPF kHz LPF TEE c ee J 500LOAD Figure 4 9 Residual FM Test Setup EQUIPMENT FM Discriminator HP 5210A Fiter Kit HP 10531A RMS Voltmeter HP 3400A 40dB Amplifier 465A Capacitors WF
285. APACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 30PF 5 300WVDC MICA DIODE SWITCHING 2NS 30V 50MA DIODE GEN PRP 100V 200MA EXTRACTOR PC BOARD RED PIN DRIVE 0 250 LG TRANSSITOR NPN SI PD 300MW FT 200MHZ TRANSISTOR NPN SI TO 18 PD 360MW TRANSISTOR NPN SI TO 18 PD 360MW RESISTOR 10K 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR RESISTOR 21 5K 1 125W F TUBULAR RESISTOR 316 OHM 1 125W F TUBULAR RESISTOR 61 9K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR NOT ASSIGNED RESISTOR 10K 25 125W F TUBULAR RESISTOR VAR TRMR 20KOHM 10 C RESISTOR 10K 25 125W F TUBULAR RESISTOR 3 16K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 10 OHM 1 125W F TUBULAR RESISTOR 10 OHM 1 125W F TUBULAR RESSITOR 79 95K 25 125W F TUBULAR RESISTOR 7 4K 25 125W F TUBULAR RESISTOR VAR TRMR 2KOHM 10 C RESISTOR 9 09K 1 125W F TUBULAR RESISTOR 10M 5 25W CC TUBULAR RESISTOR 5 1M 5 25W CC TUBULAR TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD IC LIN LM301AH AMPLIFIER IC LIN LM301AH AMPLIFIER IC DGTL SN74 00 N GATE IC DGTL SM74 08 N GATE DIODE ZNR 10V 5 DC 7 PD 4W TC 06 DIODE ZNR 10V 5 DC 7 PD 4W TC 06 FM AMPLIFIER ASSY CAPACITOR FXD 2700PF 5 300WVDC MICA CAPACITOR FXD 2700PF
286. AR RESISTOR 100 OHM 1 125W F TUBULAR RESISTOR 2 15K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR VAR TRMR 500 OHM 10 C SIDE ADJ RESISTOR 2 7 OHM 5 25W CC TUBULAR RESISTOR 178 OHM 1 125W F TUBULAR RESISTOR 68 1 OHM 1 125W F TUBULAR RESISTOR 422 OHM 1 125W F TUBULAR RESISTOR 1 5 OHM 5 2W PW TUBULAR RESISTOR 1 78K 1 125W F TUBULAR RESISTOR 2 61K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 4 22K 1 125W F TUBULAR RESISTOR 100 OHM 1 125W F TUBULAR RESISITOR 5 11K 1 125W F TUBULAR RESISTOR VAR TRMR 500 OHM 10 C SIDE ADJ RESISTOR 2 15K 1 125W F TUBULAR RESISTOR 2 7 OHM 5 25W CC TUBULAR RESISTOR 178 OHM 1 125W F TUBULAR RESISTOR 68 1 OHM 1 125 TUBULAR RESISTOR 422 OHM 1 125W F TUBULAR RESISTOR 1 5 OHM 5 2W PW TUBULAR RESISTOR 10K 2 05W F TUBULAR RESISTOR 10K 2 05W F TUBULAR RESISTOR 1 78K 1 125W F TUBULAR TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD MFR CODE 28480 00779 00779 00779 00779 28480 56289 28480 56289 56289 56289 28480 56289 56289 28480 04713 28480 28480 28480 04713 28480 28480 71400 71400 28480 00000 28480 00000 02735 28480 28480 28480 28480 02735 16299 24546 16299 24546 16299 24546 32997 01121 16299 24546 16299 75042 24546 16299 24546 16299 24546 24546 32997 16299 01121 16299 24546 16299 75042 24546 24546
287. ASSY 08640 60256 4 PIO B 1 o o z NON FUNCT IONING LINE _ CIRCUIT BOARD 6 68 A TOP VIEW 8 5 12 dB 1848 KEYOooo 1 4 224 dB R15 1500 30 48 R17 1500_ 36 4B e a R16 C7 RIS Riss ca C 3000 7680 3000 1502 25190 A3 A5 NOTE 2 th AB A13 700 uondo 0 98 POW 51006 07980 A9 PEAK DEVIATION AND RANGE SWITCH ASSEMBLY ee ee me em FM SYSTEM GAIN m PEAK DEVIATION DIFFERENTIAL GEARING FM SYSTEM GAIN dB FROM ASTP3 ON 55 6 TO A7TP3 WITH LEVELS AT A7TP3 lt 0 3Vrms P O Figure 8 29 FM Shaping Circuits and Phase Lock Loop Filter Schematic Diagram P O Change 7 M Poasa SWITCH ASSEMBLY 08640 6017 ___ 5 0200707 P O AQA2 INTERCONNECT ASSY PIOAB 9 GAJN SWITCH BOARD ASSEMBLY 08640 60254 5 L P O P NUM LI TO REDUCE PEAK DEVIATION ANNUNCIATOR P O 2009 39 2 700 uondo gor9g BPOW 82006 07980 Model 8640B Option 004 08640 90073 CHANGE 7 Cont d 1 1 Figure 8 31A Peak Deviation Band Switch Board Assembly Component Locations P O Change 7 7 46 Model 8640B Option 004 08640 90073 CHANGE 7 Cont d A9A2 Figure 6 31B A9A2 Interconnect Assembly Component Locations P O Change 7 Model 8640B Option 004 CHANGE 7 Cont d PIO ASAZAL
288. ATION Drift Rate after 2 hour warm up Time lt 0 05 ppm per h lt 2 ppm per yr Temperature 2 ppm total variation for room ambient 15 to 35 C Line Voltage lt 0 1 ppm NOTE Because the phase lock mode references the generator s RF oscillator to the counter s frequency reference the following frequency specifications are also checked in this test Frequency Stability phase lock mode Time 0 05 ppm hr Temperature 2 ppm total variation room ambient 15 to 35 C Line Voltage 5 to 10 change 0 1 ppm Load with any passive load change None measurable Level Change None measurable Mode Change CW to FM None measurable DESCRIPTION After a two hour warm up period the internal reference is measured with a frequency counter a digital to analog converter and a strip chart recorder frequency variations are noted as the specified changes are made A quartz oscillator is used as a time standard when measuring drift as a function of time and line voltage change See Table 4 1 Recommended Test Abridgements 4 89 Performance Tests Model 8640B Option 004 4 49 PERFORMANCE TESTS INTERNAL REFERENCE DRIFT RATE STABILITY TEST Cont d QUARTZ OSCILLATOR VARIABLE 9 VOLTAGE TRANSFORMER 1 MHz OUTPUT EXT OSC INPUT FREQUEN CY COUNTER TEMPERATURE CONTROLLED CHAMBER TIME BASE REAR PANEL COAXIAL SHORT BCD INPUT Figure 4 34
289. ATION DETECTOR d 2 2b 20 RI 1 PIO A9 BOTTOM VIEW 750 1 521 8 PIO i i f i LEVEL SENSE i 5 2V B 10 1 XN 051 15 5 me ewe R79 1820 0175 ps 5 zy VERNIER NOTES 511 SEE NOTE 1 1 OPEN COLLECTOR TTL i ps2 AE i 910 l TO FM AMPL 9 Ly 3 Su NERONE i CONTROL REDUCE A9 PEAK DEVIATION AND RANGE SWITCH ASSEMBLY 08640 60117 abel ORV ion ATU2 qe ee ee TOP VIEW i P O z a 10 Pl fe VETER ATTENUATOR Sener umma SCALE ANNUNCI ATOR LAMP CONTROL i 5 2V 1 i 0 3 1 TO FM AMPL 20 G5 TO OUTPUT 860 15 6 C3 E TE C94 META I POWER La R23 veviation 4259 1 1 ald Knee PIO s t i 1 0 5 CIRCUIT BOARD 1 H 1 SCALE 1 TOP VIEW 1 A TR x 5 017 See dns 2 Figure 8 31 P O 9 Peak Deviation and Range Switch Assembly Component Locations 2 of 2 10 kHz o o 10 i ASSEMBLIES TERIN OUTLINED com re m KYooooooo 3 312 IS ATRI DESIGNATIONS OF OTHER COMPONENTS ARE E MEIN acides i 1 EE ra B lt oH parar d gt 1493 i m E Enas 212 00 ATUS R28 B 6 3 12 TOP VIEW pa 82 5 oL 18
290. Add A26A2K1 0490 1080 RELAY REED IC 0 25A 150V CONT 5V COIL Page 6 3 Table 6 3 Change A26A8R11 to 0757 0288 RESISTOR FXD 9 09K 1 0 125W Service Sheet 6 schematic Add A9R2 787 ohms with one end connected to pin 28 of P1 and the other end grounded through a wire with a 94 color code Delete A13R6 NOTE If A9 is replaced AI3R6 should be added If Al 3 is re placed A9R2 should be removed Service Sheet 9A schematic Change A11Q1 to 1853 0020 Change A11R2 and R6 to 196K 7 5 Manual Changes Model 8640B Option 004 MANUAL CHANGES CHANGE C Cont d NOTE See paragraph 7 15 for recommended instrument modification Service Sheet 13 schematic Replace appropriate portion of schematic with attached partial schematic A26A2 A A26A2 AM OFFSET AND PULSE 1 SWITCHING ASSY 08640 60014 1 5 2 is l PIO 2 CR5 15 E MM Figure 7 1 A26A 2 AM Offset and Pulse Switching Assembly Backdating Change C c Service Sheet 15 schematic Change 26 8 11 to 9090 ohms NOTE HP 0757 0441 8250 ohms is recommended replacement if A26A8RI1 should fail Service Sheet 22 Principles of Operation Under Input Voltage Al 2 and A14 delete the last sentence and add the following paragraph The A12 Rectifier Assembly contains five full wave rectifiers and a crowbar to protect the instrument from excessively
291. B BASE RND 5 JGK MGP DECAL OUTPUT LEVEL VERNIER KNOB CONC RND 5 IN JGK MGP DECAL OPTION 001 MOD FREQUENCY VERNIER GLIDE NYLON NUT KNURLED R 15 32 32 THD 12 THK 61 INSULATOR MISC CLIP PANEL 201 ID CONTAINER PLSTC POLYSTY 1 062 LG 1 062 CLAMP CAP FILTER AIR EXP AL 3 6 W 6 L WRENCH COMBINATION CONNECTOR 15 CONTRACTS PANEL FRONT SHIELD FM AMPLIFIER SCREW METER ZERO SUPPORT PC BOARD SUPPORT MODULE INSULATOR COUNTER INSULATOR CONNECTOR EXTRUSION TOP EXTRUSION BOTTOM COUPLER SHAFT FRONT CASTING CLAMP METER NOT ASSIGNED 5H FM LENS DIFFUSING KNOB DIAL ASSY WINDOW FRONT DIAL AND GEAR ASSY OPTION 001 MOD FREQ VERNIER SKIRT MFR CODE 56289 56289 56289 56289 56289 0057R 87034 71400 75915 28480 78189 28480 28480 28480 28480 28480 28480 OPTION 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 OPTION 28480 28480 REPLACEABLE PARTS MFR PART NUMBER 36D392G050AC2B 36D392G050AC2B 36D392F075BB2B 36D822G025AC2A 36D822G025AC2A PME 271 M 522 2 3121 25 1120 0539 2101 10 00 0340 0486 0370 2376 0370 2378 0370 2379 0370 2380 0370 2381 001 AUD OUT 3 0370 2382 0370 2623 0370 2387 0370 0623 0370 2446 0403 0026 0590 1011 1400 0825 1540
292. BAND CODE RA SUP GAIN COMP OUT VARACTOR ANODE VARACTOR LGT DRIVE FUNCTIONING LINE JE p REDIICE PK DEV 98 Cs CATHODE 10 iGT DRIVE GND RETURN DR AMP OUT BUF AMP IN SHAPE 913 LO BAND 2 912 LO BAND 1 945 gt 3 9 GND RET SHAPE CMN NON 5 1 C B 2 8 D 945 DR AMP FDBK 95 978 948 x 01 968 FM ENABLE 947 908 906 904 905 901 903 90 925 e gt gt 928 A LGT DRIVE C923 926 LOT COMMON oo 1956 MIR RET A UA 2 A LA p A13 MODULATION METERING MOTHER BOARD ASSY 08640 60057 2 v 24 26 5 M B 12 Now 9 7 5 M quM REFERENCE DESIGNATIONS WU qe C lt FM NO PREFIX 3 INPUTIDUTPUT T GEO MEAN 94 DIVIDER P3 J15 FILTERS er Dep ob das Ri 2 ob pes w4 5 9 12 13 51 5 2V 82 GB PUB T rupem A13 gala VAM XD 15 RISER ASSY 18640 60018 Celo d SQ BOTTOM VIEW EU FM 1 ZI XA15 a a 2 3 4 5 6 T7 9 9 D n m p M bo p f j 51 1 SEE SERVICE SHEETS 6 9 9A AND er PIER t 994 o FOR COMPONENT VALUES ede d i 16 090
293. C Model 8640B Option 004 Initial Test Conditions Top and bottom covers removed see Service Sheet G for removal procedure Extend All Variable Frequency Modulation Oscillator Assembly on extender board see Service Sheet D for removal procedure Initial Control Settings AM INT AUDIO OUTPUT LEVEL CW MODULATION FREQUENCY 400 Hz Fixed Amplitude Stability and Distortion The signal level of the oscillator is adjusted by selection of R28 for best compromise between harmonic distortion and amplitude stability squeg ging at turn on or range change Table 5 Factory Selected Components Variable Frequency Modulation Oscillator Troubleshooting Component Test Conditions and or Circuit Control Settings MODULATION OSCILLATOR ASSY All Initial conditions and settings Then set MODULATION FRE QUENCY to 1000 Hz fixed and to each of the variable ranges Xl X10 etc Vary the vernier on each range Set AM to OFF 8 36 If Indication Normal Indication is Abnormal Peak to peak voltages are Check appropriate as shown on schematic circuit and replace faulty component DC voltages are as shown Replace faulty compon on schematic ent Model 8640B Option 004 A11 OPTION 001 TOP SIDE with covers removed E NES ts UEM E pi bes MER LA1S 12 A11 OPTION 001 with covers removed A11 OPTION 001 BOTTOM SIDE w
294. C and DC and an internal modulation signal in INT The PEAK DEVIATION vernier adjusts the input level into a unity gain Buffer Amplifier In addition to driving the FM amplifier the Buffer Amplifier drives the Over Deviation Detector and the Meter Attenuator In the event that the input signed exceeds 1 1V the Over Deviation Detector turns on the REDUCE FM VERNIER lamp The Meter Attenuator scales the 8 20 Model 8640B Option 004 input signal to the meter circuits in such a way that a 1 Vpk input corresponds to the deviation se lected when read on the meter Modulation Oscillator Service Sheets 9 and 9A Internal AM and FM is provided by the Modulation Oscillator The oscillator drives either the AM modulation circuits and AM OUTPUT port or the FM modulation circuits and FM OUTPUT port or all four The oscillator is enabled whenever either the AM or FM switch is in INT The standard modulation oscillator shown on Service Sheet 9 has two fixed frequencies 400 Hz and 1 kHz The oscillator supplied with Option 001 shown on Service Sheet 9A has in addition five variable frequency ranges covering from 20 Hz to 600 kHz Power Supplies and Fan Service Sheets 22 and 23 The instrument has five regulated supply voltages 44 6 20V 20V 5 2V 5 2V supplies are protected against overloading over voltage and reverse voltage An LED annunciator on each supply indicates proper operation when on The cooling fa
295. C5 HP PART NUMBER 0698 7260 0698 7260 0698 7264 0698 7243 0698 7229 0757 0442 0757 0416 0698 3442 0757 0442 0757 0279 0757 0442 0698 0083 0698 0083 0698 0083 0757 0416 0757 0416 0698 7229 0757 0280 0698 7248 0698 7248 0698 7229 0698 7229 0698 7236 0811 1662 0698 7219 3101 1729 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 1820 0077 1820 0054 1820 0054 1820 0174 1820 0077 1820 0328 1820 0701 1820 0701 1820 0701 1820 0701 1820 0701 1820 0701 1820 0511 1820 0205 1820 0054 1820 0054 1820 0511 1820 0511 1820 0546 1820 0546 1820 0546 1820 0546 1820 0546 1820 0546 1820 0328 1820 0077 1820 0205 1820 0546 1826 0092 1902 3070 1902 3182 08640 60026 0160 3094 0160 3094 0160 3094 0160 3094 0160 3094 QTY TABLE 6 3 REPLACEABLE PARTS DESCRIPTION RESISTOR 10K 2 05 RESISTOR 10K 2 05 RESISTOR 14 7K 2 RESISTOR 1 965 2 RESISTOR 511 OHM 2 RESISTOR 10K 1 12 RESISTOR 511 OHM 1 RESISTOR 237 OHM 1 RESISTOR 10K 1 12 RESISTOR 3 16K 1 RESISTOR 10K 1 12 RESISTOR 1 96K 1 RESISTOR 1 96K 1 RESISTOR 1 96K 1 RESISTOR 511 OHM 1 NOT ASSIGNED RESISTOR 511 OHM 1 NOT ASSIGNED RESISTOR 511 OHM 2 RESISTOR 1K 1 125 RESISTOR 3 16K 2 RESISTOR 3 16K 2 RESISTOR 511 OHM 2 RESISTOR 511 OHM 2 RESISTOR 1K 2 05 RESISTOR 47 OHM 5 RESISTOR 196 OHM 2 SWITCH PB STA DPD NSR P O A8A2S1A NSR P O A8A2S1A
296. CIALTY PRINTERS INC ame INC ALLEN BRADLEY CO TEXAS INSTR INC SEMICOND CMPNT DIV RCA CORP SOLID STATE PYROFILM CORP MOTOROLA SEMICONDUCTOR PRODUCTS VIKING INOUSTRIES INC FAIRCHILO SEMICONDUCTOR DIV TECHNICAL WIRE PRODUCTS INC C AND COMPONENTS INC CHERRY RIVET DIV TOWNSEND CO CL AROSTAT MFG CO INC TEL EDYNE SEMICONDUCTOR CORNING GL WK ELEC CMPNT DIV MEPCO ELECTRA CORP CABLEWAVE SYSTEMS INC GOWANCA ELECTRONICS CORP CORNING GLASS WORKS BRADFORD SPEC CONNECTOR CO INC GRIES REPRODUCER CORP METHODE ELECTRONICS INC NATIONAL SEMICONDUCTOR CORP HEWLETT PACKARD CO CORPCRATE HQ MEPCO ELECTRA CORP 80URNS INC TRIMPOT PRODO DIV SPR AGUE ELECTRIC CO BUSSMAN MFG OF MCGRAW EOISON CO CTS CORP CHICAGO MI NIATURE LAMP WORKS COMPONENTS CINCH DIV ELECTRO MOTIVE MFG CO INC FEDERAL SCREW PRODUCTS CO 4 ELECTRONICS CORP INC PHILADELPHIA OIV LITTLEFUSE INC OAK IND INC SW OIV ILLINOIS TOOL WORKS INC SHAKEPROOF WALOES KOHINOOR INC Cow INDUSTR IES SCHN ITZER ALLOY PRODUCTS CO ALL STAR PROD INC SM ETH HERMAN H INC GAVI YT WIRE amp CABLE CAPAC ITOR DIV SEASTROM MFG CO AMPHENOL SALES D I V OF BUNKER RAMO CALE ELECTRONICS INC QUALITY COMPONENTS INC WECKESSER CO TNC ART WIRE STAMPING CO INDUSTRIAL RETAINING RING CO SEAL EC TRO CORP Address Zip Code ENGLAND NOGALES AZ ANAHEIM SAN FRANC ISCO CA HARRI SBURG PA MILWAUKEE WI DALLAS TX SOMMERVI
297. CTRC 20K 2K 10 CC NSR PART OF R1 RESISTOR 28 7K 1 125W F TUBULAR SWITCH PB 1 STA RECT DPOT SWITCH SL DPOT NS 5A 125VAC DC SWITCH TGL SUBMIN SPDT 5A 115VAC SLDR TRANSFORMER POWER CABLE UNSHIELD 3 COND 18AWG CABLE ASSY COAX 9 579 CABLE COAX ASSY 11 764 CABLE ASSY FM INPUT OUTPUT WIRE 24AWG BK 300V PVC 7X32 WIRE 24AWG W G GY 300V PVC 7X32 WIRE 24AWG W G GY 300V PVC 7X32 CABLE COAX 086 OD CABLE COAX 086 OD CABLE COAX 0 85 OD WIRE 24AWG BK 300V PC 7X32 WIRE 24AWG W G BL 300V PVC 7X32 WIRE 24AWG W G GY 300V PVC 7X32 MFR CODE 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 73734 28480 28480 28480 28480 28480 28480 28480 28480 28480 83330 28480 28480 28460 28480 28480 28480 05574 71785 28480 90949 13511 74868 28480 28480 28480 28480 28480 28480 16299 87034 79727 09353 28480 28480 28480 94142 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 REPLACEABLE PARTS MFR PART NUMBER 08640 40055 08640 60036 5040 0388 5040 0389 5040 0390 3030 0007 0624 0267 0626 0002 1200 0043 3160 0217 5040 0170 3030 0007 5040 0447 08620 20016 08640 00014 08640 00015 1660 0403 0026 8160 0238 8160 0239 08640 20228 08640 40052 08640 20057 08640 00077 08640 00078 5020 0343 119 08640 00072 08640 00073 08640 00074 7120 4244 086
298. CW signal at 13 dBm Set test generator s FM switch to OFF and tune both generators for a 1 MHz signal at the top graticule line on the analyzer s display 7 Set test signal generator s FM switch to set test oscillator s frequency for approximately 2 079 kHz and adjust oscillator s amplitude controls for a reading of 5 ie 5 kHz on test generator s panel meter 0 5 scale Tune oscillator s frequency for the first carrier null on the analyzer s display at least 50 dB below the top graticule line With frequency counter measure frequency of modulating signal It should be 2 079 kHz 10 1 871 2 287 kHz 8 Use procedures given in steps 6 and 7 to check indicated accuracy on the remaining bands by setting test generators RANGE switch as shown below On each range set FM to OFF and tune generators for a 1 MHz difference Set reference on analyzer set FM to AC with modulating signal s amplitude set for a test generator panel meter reading of 5 and its frequency set to approximately 2 079 kHz Then tune modulating signal s frequency for first carrier null The signal s frequency should be as shown RANGE FREQUENCY Reference Generator Mod Signal Frequency MHz TUNE Frequency kHz 128 256 256 MHz 257 MHz 64 128 128 MHz 129 MHz 32 64 64 MHz 65 MHz 16 32 32 MHz 33 MHz 8 16 16 MHz 17 MHz 4 8 8 MHz 9 MHz 2 4 4 MHz 5 MHz 1 2 2 MHz 3 MHz 9 Disconnect test Signal Generator and analyzer from mixer and connect t
299. D 33 C35 3 LINES LABELED OW BAND AT 5 o 847128 LOW BAND L pM INPUT E HIGH BAND AT INPUT n US 130 64 128 MHz 24 AND 81 4 AT OUTPUT WHICH ARE b a 0 125 0 115 i TIL FOR WHICH OPEN POSITIVE 15 HIGH AND GROUND 15 LOW B amp 64 128 po SEE BACKDATING TABLES 1 AND 7 2 o yg 8868108 Wir BAND i 31 gt 832 4 MHz BAND cas E E RATEN 128 256 Mig HIGHBAND 5 os up 12 1262256 MZ 4 8 I 1 T B 128 256 iN e F i 5 1 1 RF TO DIVIDERS CLUDES ASSEMBLY NUMBER ag RI DF ASSEMBLY al 3 E 0 47 pF pu yv IS AIRI DESIGNATIONS OF OTHER COMPONENTS ARE 151 152 5 2 5 2 dah GEUS Ma eae e ate E 1 1 ag Wn I 2 l Li B35 9 11 1416 18 2 23 26 28 32 34 me A1 2 12 86 7 12 13 uum 10 A10AT1 Figure 8 40 RF Filters Schematic Diagram J FAL TERS OPTION 004 14144 Figure 8 39 A10A1 RF Filter Assembly Component Locations 2 of 2 ALO DIVIDER FILTER ASSY 7 a a
300. D A7R67 A7R68 A7RO RN 26 1 ica 4 1 1 R57 E JM cmo 281 DC VOLTAGES ARE WITH S COUNTER MODE LOCK SWITCH T xis SET TO OFF TOLERANCE 15 10 FM SYSTEM GAIN dB m AUK 7348 t FROM ASTP3 55 6 TO ATTP3 WITH LEVELS AT A7TP3 lt 0 3Vr ms dif RANGE MHz 60 3G RAB VIEW 0 51112 4 8 16 32 64 128 256 512 sad SEC cu 22 DEVIATION TO TO TO TO TO TO TO C i 112 4 8 16 32 64 128 256 512 1024 d RED da Ra 2511 0 dB R50 5 6 CIRCUIT BOARD TOP VIEW 6 dB Ro R51 75 0 5 3 12 dB 7500 0000 2e 18 dB 6 5 KEY j 1 24 dB it sop t R64 20 dB ME R53 CRIO 121 1 ot 36 dB L4 25 2570 ROS 2 06 R54 162 0 1 tod l 1 1 c2 ul 7 R6 20V 2 20 s K gt T uF 7 178K 1 8M 5 5N 10 5V 46 SAK lt 52 KX 3 lt 20 ee ee 8 2 _ 186 031 R10 R8 13 3K R9 38 3K 20V SS Q3 COMPLETE AS SHOWN RI R42 clo CRIO ei i Nis amp 5V ws me VAR
301. DER Y 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000FF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 1000WVDC CER 010 80 20 100WVDC 01UF 80 20 100WVDC 1000PF 100 100WVDC 010 80 20 100WVDC 1000PF 10 1000WVDC 1000PF 1000WVDC CER 1000PF 10 1000WVDC 4 70 10 35VDC 1000PF 10 1000WVDC 4 70 10 35VDCM 2 2UF 10 20VDC CER CER CER CER CER CER CER CER CER CER CER CER CER 100 10 20VDC TA SOLID lUF 10 35VDC TA SOLID 100 10 20VDC TA SOLID 1000FF 10 1000WVDC 1000PF 10 1000WVCD 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 10 1000WVDC 1000PF 10 1000WVDC 10 1000WVDC CER 010 80 20 100WVDC 010 80 20 100WVDC 010 80 20 100WVDC 010 80 20 100WVDC 01UF 80 20 100WVDC CER CER CER CER CER CER CER CER CER CER CER CER CER CER CER CER MFR CODE 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 79136 24546 24546 24546 24546 24546 24546 24546 24546 24546 28480 28480 28480 28480 28480 28480 28480 28480 28480 71785 71785 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 56289 28480 56289 56289 56289 56289 5
302. Detector 20 os s s s s 423A 15 kHz Low pass Filter LPF 20 s s o CIR Q TEL 7 Pole 40 dB Amplifier HP 465A Oscilloscope HP 180A 1801 A 1820C 50 Ohm Load HP 11593A Nine Inch Cable HP 10502A Adapter HP10110A 0 001 gF Capacitor HP 0160 0153 10 Resistor HP 0757 0442 4 85 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 46 INCIDENTAL AM TEST Cont d PROCEDURE 1 4 86 Connect equipment as shown in Figure 4 11 with network adapter tee and detector connected as shown after setting Signal Generator s controls as follows Meter Function AM COUNTER MODE EXPAND 2 2 2 Off LOCK Source AM INT MODULATION o s aca aoa wx Wow E Y 60 4 Fully cew MODULATION FREQUENCY 1 kHz FM OFF PEAK DEVIATION um cm NN uv uox ou 2 56 MHz PEAK DEVIATION Vernier Fully cw RANGE 256 512 MHz FREQUENCY TUNE i poo o ppo popopo 256 MHz OUTPUT LEVEL Switches 13 dBm OUTPUT LEVEL Vernier CAL RF ON OFF Set MODULATION for 10 AM as read on panel meter Adjust oscilloscope s vertical gain c
303. Deviation and Range Switch Assembly Model 8640B Option 004 Divider Filter Assembly 11 Variable Frequency Modulation Oscillator Assembly Option 001 A19 Output Level 10 dB Assembly A26 AM AGC and RF Amplifier Assembly 6 18 and 6 2 are breakdowns of the generator s cabinet parts and the parts that com prise the Type N connector Jl Table 6 1 Part Numbers for Exchange Assemblies Reference Designation Description Output Level Assy 1 dB RF Oscillator Assy RF Scaler Assy Counter Lock Board Assy Output Level Assy 10 dB 6 2 Part Number 08640 60077 08640 60062 08640 60098 08640 60099 08640 60097 08640 60168 08640 60087 08640 60027 08640 60078 08640 60060 Model 8640B Option 004 attenuator lsolator termination Rn fan motor UK RR AURI C battery Cr E TU capacitor ITE DT coupler diode diode thyristor varactor directional coupler ete enone delay line Shay ee erae annunciator signaling device audible or visual lamp LED alternating current accessory adjustment analog to digital ee ees audio frequency 168 automatic frequency control automatic gain amplitude modula vnde cantos amplifier automatic phase beat frequency oscillator binder head eine calibrate counter clock wise ceramic REFERENCE DESIGNATIONS di iA eed doy circulator electrical connector stationary portion cm coil induct
304. E n 12 4 L i 1 1 H 2 mou SERIE ASSEMBLY 5060 9406 icy P E E H Q3 1854 Wi i 0250 TO LINE lt iq 4 CRIS C 22 1854 1 20 Qi XA22 24 E o DELETED 1201 AI2R AIZR gt CRIS A NOTES Do 0 41 1 SHOWN BELOW 15 AN ELECTRICAL 41 APPROXIMATION OF THE VOLTAGE i AQUI 2 REGULATOR 221 2 TOP VIEW ed 1 01 1854 1 1 6 t 0 CIRCUIT BOARD i TOP VIEW 10 6 90066 6 Bere KEY 1201 200 7 A22Q1 4 2 VALUE OF F 15 2 FOR 100 120V TOP VIEW AND 1 25 AMP FOR 2201240 Pod G 3 VOLTAGES SHOWN ARE APPROXI M C ATE AND MAY VARY AS LINE C VOLTAGE VARIES TOLERANCE 15 APPROXIMATELY 105 i SEE BACKDATING 7 1 AND 72 D DESIGNATIONS WITHIN DUTLINED m ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IH CLUDES ASSEMBLY NUMBER s Rl OF Al I AIR DESIGHATIONS OF OTHER COMPONENTS ARE 1 COMPLETE 45 SHOWN ce dam s A12 A14 20 A22 Figure 8 74 Power Supply Circuits Schematic Diagram POWER SUPPLY CIRCUITS NHOS OPTION OM 14734 Figure 8 73 A22 20V and 20 Regulator Assembly Component Locations 8 64 SERVICE SHEET 23 PRINCIPLES OF OPERATION 5 2V Regulator A18 The 5 2V regulator functions similarly to the 5 2
305. E 52 10939 5 52 10939 99 1902 0049 3 332070 5 3 332070 5 08640 60060 08640 60078 2295 616 2295 412 0550 0053 1500 0382 2190 0020 2360 0119 3130 0446 3130 0445 08640 60061 08640 60054 C4 1 8 TO 751 F C4 1 8 TO 3161 F C4 1 8 TO 2371 F C4 1 8 TO 1002 F C4 1 8 TO 2872 F C4 1 8 TO 1001 F ET50X202 ET50X202 C4 1 8 TO 422R F 0360 1514 0360 1514 08640 60005 MODEL 8640B OPTION 004 REFERENCE DESIGNATION 20 1 A20C2 A20C3 A20C4 A20C5 A20C6 A20C7 A20C8 A20CR1 A20CR2 A20CR3 A20CR4 A20CR5 A20DS1 A20DS2 20 1 A20F2 A20MP1 A20MP2 A20Q1 A20Q2 A20Q3 A2004 A20Q5 2006 2007 A20R1 A20R2 A20R3 A20R4 A20R5 A20R6 A20R7 A20R8 A20R9 A20R10 A20R11 A20R12 A20R13 A20R14 A20R15 A20R16 A20R17 A20R18 A20R19 A20R20 A20R21 A20R22 A20R23 A20R24 A20R25 A20R26 A20R27 20 1 A20TP2 A20TP3 A20TP4 A20TP5 A20TP6 A20TP7 A20TP8 A20TP9 A20TP10 A20U1 A20U2 A20VR1 A20VR2 A20VR3 A20VR4 A20VR5 HP PART NUMBER QTY 0160 01531 0180 0229 0180 02341 0180 0228 0160 03001 0180 2208 0180 0229 0160 3094 1901 0159 1901 0050 1901 0159 1901 0050 1901 0050 1990 0326 1990 0326 2110 03321 2110 00471 4040 0748 1480 0073 4040 07532 1480 0073 1884 0012 1854 0232 1200 0173 1854 0022 1200 0173 1853 02241 1200 0173 1853 0020 1854 00231 1884 0012 0698 3160 0698 3438 0757 0462 3 0698 0083 0698 34071 0698
306. E Service Sheet 5 DESCRIPTION The VT pot is aligned so that it will not hit either end stop as the FREQUENCY TUNE control is tuned through its full range This adjustment should be performed whenever the pot has been replaced 5 23 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 35 Vr POT A3R1 ADJUSTMENT Cont d CENTER TERMINAL POT CASTING SETSC REW GEAR SETSCREW CENTER TERMINAL FIRST TERMINAL Figure 5 5 Vr Pot Adjustment 1 Set FREQUENCY TUNE fully cw 2 Tighten the bushing and set VT pot shaft fully cw 3 Install pot with gear in casting so that center terminal 934 wire is in line with casting setscrew see Figure 53 4 Tighten setscrews in gear not casting setscrew 5 Rotate the pot cw so that casting setscrew lies between first and center terminals of pot sed Figure 5 3 B 6 Tighten casting setscrew 7 Perform the VT Voltage Adjustment 5 36 5 24 Model 8640B Option 004 Adjustments ADJUSTMENTS 5 36 VT VOLTAGE ADJUSTMEfVT REFERENCE Service Sheets 5 10 and 11 DESCRIPTION This procedure should be performed whenever either the VT pot the assembly or the A10A2 assembly has been replaced PROCEDURE 1 Set Signal Generator s controls as follows Meter Function LEVEL COUNTER MODE EXPAND 04 Off LOCK a us 4 Ap da ik oco SO Source FM OFF RANGE s s s s 256 512 MHz
307. E 3 i 1 5 7 p E mena uim ludi 2 MEM 245 i opm wes 87 NEP Al T dd ECL 110 16 NUIES REFERENCE DESIGNATIONS VIEW m n YII CIRCUITS SET FOR 0 5 1 MHz BAND 8h 1 5 M Boman 5 AMAXIISAPRINTD CIRCUIT SPIRAL dil SUME CAR 1000 0145 hp 3 OPEN CI LECTOR TIL RU 8 20 EcL i TOIT Tris 4 LOGIC FVELS ON THIS SCHEMATIC LIS ANFI d BELONG TO AND FAMILIES I r 15 PECES mea GROUNDS HIGH AND OPEN INEGATI VEI os U tbe 15 LOW EXCEPTIONS ARE LINES pices bys m XE XN C9 150 0165 LABELED LOW BAND AT OUTPUT E Mere m U 5 9 12 5 n MMe ss HIGH BAND AT OUTPUT G AND Hun w 1820 0557 1820 0143 bose 1820 0102 jn 4 y 1 0 Me pi ow 1000 EECL D OlyF ECL 2 2 pF ECL 2 7 2 HICH AND GROUND 1S LOW 1 4 180002 IOP VIE 1 SEE BACKDATING CARIES T TIAND 7 2 woo ECL DEL FTED A10A2C5 AIA u 5 g FECI 16 T 19 m dc 10 03 0 48 Un 2 2 5 6 Aon BOARD ai em Li 1r yis M 121 5 VIEW a c Hxc 100079 ERO 10030 Lc imam E Hop ca 180945
308. ECTIFIER i 20 19 18 17 ca 4B 2 x RES 21 gt 44 6V SUPPLY 2 P 20V SUPPLY NC gt 23 NC 24 gt 20V SUPPLY poses 1 1 nam ee XA24 ECHEN 26 5 2 1 9 ed Se ees 1 17 28 gt GROUND 1 118 NC gt 29 NC ae ns 30 gt RF LEVEL VOLTAGE SEC 11 6 TI3 4 REFERENCE DESIGNATIONS WITHIN OUTLINED gt aoe Dc MEER 1 HUE NEN 5 4 3 2 AMIAGC 109 8 7 65 43 2 DESIGNATIONS OF OTHER COMPONENTS ARE SERIES Sa AND RF COMPLETE AS SHOWN TC EM REGULATOR fir HE EN D M D 16 17 18 192 ee 1 D D M 15 16 17 18 19 2 320 REGULATOR mas POWER SUPPLY MOTHER BOARD option oa BA 0000000 00 momo M mi E en m Se r ja NEN A17 Figure 8 77 A17 Power Supply Mother Board Assembly Component Locations Figure 8 78 Power Supply Mother Board Schematic Diagram 8 67 Service Model 8640B Option 004 A13 TOP VIEW QECILATOR REROVE SHORT PANE 09065 4 8 5 Power Supply Mother Board 17 Figure 8 79 A13 Modulation Metering Mother Board Assembly component Locations lof 2 SERVICE SHEET 24 8 68 Model 8640B Option 004 Service zi gt gt m rm gt A gt m v o m wi lt mee COUNTER
309. ELETED A3A4R5 ASCRI 4 945 m 4 9 ASR21 9 6 A9C7 A9R2 A9R3 212 4 l NOTES Re R5 1 ALL VOLTAGES ARE WITH SWITCH Hg 3 UM UT M SET OFF TOLERANCE 15 10 Fog R J RO 3 2 5 t SEE BACKDATING TABLES 7 1 AND 7 2 i 1 51 4 11 Ca Ei DdB oap VIEW CIRCUIT BOARD 648 TOP VIEW All 12 di 4 a 18 dB o 1 4 Ki C24 BB 9 12 i Hn 30 9 10 REFERENCE DESIGNATIONS WITHIN OUTLINED m RB R15 ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN poi 1 1500 36 NE 1 1 n A3 A5 qu o 10 12 13 Figure 8 27 Amplifiers Schematic Diagram 8 29 SERVICE SHEET 7 PRINCIPLES OF OPERATION General The FM shaping networks in conjunction with the FM amplifier Service Sheet 6 and the peak deviation attenuator condition the modulation signal to drive the RF Oscillator s varactor diodes which electrically tune the oscillator The tuning sensitivity of the oscillator with respect to the modulation input decreases as the tuning voltage becomes more positive The shaping networks compensate for the non linear tuning characteristic In addition the varactor diodes can be tuned by the phase lock circuits to synchronize the RF oscillator with an accurate and stable reference oscillator FM Enable A7 The varactor diode
310. EPLACEABLE PARTS REFERENCE HP PART QTY DESCRIPTION MFR MFR PART NUMBER DESIGNATION NUMBER CODE AQMP 6 3050 0099 1 WASHER FL MTLC 25 IN ID 5 IN OD 28480 3050 0099 9 7 5040 0218 1 COUPLER SWITCH SHAFT 28480 5040 0218 AQMP 8 08640 00019 1 SUPPORT SWITCH 28480 08640 00019 AQMP 9 08640 40039 1 SHAFT ADJUSTABLE 28480 08640 40039 9 10 08640 40045 1 SHAFT SWITCH BAND 28480 08640 40045 AGPI 1251 2799 T CONNECTOR PC EDGE 15 CONT SOLDER EYE 71785 251 15 30 400 2100 3262 1 RESISTOR VAR 2 5K 10 71450 550 A9R2 NOT ASSIGNED A9R3 NO ASSIGNED AQR4 0757 0280 RESISTOR 1K 1 125W F TUBULAR 24546 C4 1 8 TO 1001 F A9R5 0757 0278 RESISTOR 1 78K 1 125W F TUBULAR 24546 C4 1 8 TO 1781 F A9R6 0757 0274 RESISTOR 1 21K 1 125W F TUBULAR 24546 C4 1 8 TO 1213 F A9R7 0757 0416 RESISTOR 511 OHM 1 125W F TUBULAR 24546 C4 1 8 TO 511R F A9R8 0698 0082 als RESISTOR 464 OHM 1 125W F TUBULAR 16299 C4 1 8 TO 4640 F A9R9 0757 0280 RESISTOR 1K 1 125W F TUBULAR 24546 C4 1 8 TO 1001 F A9R10 0698 8211 RESUSTOR 2K 25 25W F 19701 MF52C1 4 T9 2001 C A9R11 0757 0280 RESISTOR 1K 1 125W F TUBULAR 24546 C4 1 8 TO 1001 F A9R12 0698 8212 RESISTOR L6 25 125W F TUBULAR 19701 MF4C1 4 T9 6001 C A9R13 0698 5669 RESISTOR 1 5K 25 125W F TUBULAR 19701 MF4C1 8 T9 1501 C A9R14 0698 8213 RESISTOR 3K 25 125W F TUBULAR 19701 MF4C1 4 T9 3001 C A9R15 0698 5669 RESISTOR 1 5K 25 125W F TUBULAR 19701 MF4C1 8 T9 1501 C A9R16 0698 8213 RESISTOR 3K 25
311. ESISTOR 17 8 OHM 2 05W F TUBULAR RESISTOR 287 OHM 2 05W F TUBULAR RESISTOR 287 OHM 2 05W F TUBULAR RESISTOR 51 1 OHM 1 125W F TUBULAR RESISTOR 10 OHM 1 5W F TUBULAR RESISTOR 5 11K 1 125K F TUBULAR RESISTOR 17 8 OHM 2 05W F TUBULAR RESISTOR 287 OHM 2 05W F TUBULAR RESISTOR 287 OHM 2 05W F TUBULAR RESISTOR 51 1 OHM 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 10 OHM 1 5W F TUBULAR RESISTOR 17 8 OHM 2 05W F TUBULAR RESISTOR 287 OHM 2 05W F TUBULAR RESISTOR 287 OHM 2 05W F TUBULAR RESISTOR 75 OHM 1 125W F TUBULAR RESSITOR 10 OHM 1 5W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 316 OHM 2 05W F TUBULAR RESISTOR 196 OHM 2 05W F TUBULAR RESISTOR 12 1 OHM 2 05W F TUBULAR RESISTOR 422 OHM 2 05W F TUBULAR RESISTOR 422 OHM 2 05W F TUBULAR RESISTOR 133 OHM 1 125W F TUBULAR RESISTOR 82 5 OHM 1 125W F TUBULAR MFR CODE 28480 56289 56289 56289 56289 56289 56289 56289 56289 56289 28480 56289 56289 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 24226 24226 24226 24226 24226 24226 24226 24226 24226 24226 24226 24226 24226 24226 28480 28480 28480 28480 04713 24546 24546 24546 19701 24546 24546 24546 24546 24546 19701 24546 24546 24546 24546 24546 24546 19701 24546 24546 24546 24546 19701 24546 24546 24546 24546 24546 24546 16299 24546 REPLACEABLE PARTS MFR PART NUMBER
312. EST EQUIPMENT REQUIREMENTS FOR 56 1112 1 U AND SG 1112 v 2 U MAINTENANCE NOMENCLATURE CATEGORY D POWER METER HP 435A 8481A D STANDARD FREQUENCY HP 105A D VOLTMETER RMS HP 3400A D VARIABLE PHASE OSCILLATOR HP 203A D VOLTMETTER VECTOR HP 8405A D VSWR BRIDGE WILTRON 60N50 D TOOLS AND TEST EQUIPMENT AVAILABLE TO THE ORGANIZATIONAL REPAIR PERSON BECAUSE OF HIS HER ASSIGNED MISSION TM 11 6625 2780 14 amp P NATIONAL NATO STOCK NUMBER TOOL NUMBER TM 11 6625 2780 14 amp P REFERENCE CODE A VISUAL EXTERNAL B OPERATIONAL REPLACE KNOBS FUSES ETC D 6 SECTION IV REMARKS t U S GOVERNMENT PRINTING OFFICE 1981 703 029 344 TEAR P ONG PERBOR LINE THEN PUBLICATION NUMBER TM 11 5840 340 20P BE EXACT PIN POINT WHERE IT IS FIGURE NO SSG I M DeSpirit of FORM 79 2028 2 JOT DOWN THE ABOUT IT ON THIS FORM CAREFULLY TEAR IT OUT FOLD IT AND DROP IT IN THE MAIL Reason PRINTEO NAME GRADE OR TITLE AND TELEPHONE NUMBER PRE VIOUS EDITIONS ARE OBSOLETE RECOMMENDED CHANGES TO EQUIPMENT TECHNICAL PUBLICATIONS SOMETHING WRONG WiTH THis FROM PRINT YOUR UNIT S COMPLETE ADDRESS Commander Stateside amy Depot ATTN AMSTA US Stateside N J 07703 DATE SENT 10 July 1975 PUBLICATION TITLE Radar Set AN PRC 76 PUBLICATION DATE 23 Jan 78 IN THIS SPACE TELL WHAT IS WRONG AND WHAT SHOU
313. EVEL MR VERNIER INHIBIT V REFEREHCE DESIGNATIONS WITHIN OUTLINED ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER g OF ASSEMBLY 15 DESIGNATIONS OF OTHER COMPONENTS COMPLETE 45 SHOWN VL METER ATTENUATOR FULE Cw 51 REFERENCE DESI F iJ 1 E 16 Al A1SA2 A26 Figure 8 55 RF Vernier Schematic Diagram 8 51 SERVICE SHEET 17 PRINCIPLES OF OPERATION General Front panel meter M1 indicates one of three quantities selected by Meter Function switch 251 For each function the metering circuitry performs the following 1 AM percent modulation X10 The ac component of the modulation signal from MODULATION potentiometer R2 is peak detected and amplified One range of autoranging is provided at 30 maximum Logic circuitry selects the appropriate amplifier gain and meter scale lamp 2 FM peak deviation kHz or MHz The ac component of the modulation signai from the Meter Attenuator section of PEAK DEVIATION switch is peak detected and amplified No autoranging is provided The scale lamp is selected by the PEAK DEVIATION switch 3 LEVEL the RF output level VOLTS or dBm A positive dc voltage propor tional to the AGC voltage of the A26A4 AGC Amplifier Assembly is amplified One range of autoranging is provided at 30 maximum Logic circuitry selects the appropriate amplifier gain and met
314. F C4 1 8 TO 1102 F REPLACEABLE PARTS REFERENCE DESIGNATION A5R31 A5R32 A5R33 A5R34 A5R35 A5R36 A5R37 A5R38 A5R39 ASR40 ASR41 ASTP1 5 2 A5TP3 5 4 5 ASTP6 501 6 6051 6052 6053 6054 6055 6056 6 1 A6R1 AT 7 1 ATC2 7 3 7 4 7 5 7 6 ATCT 7 8 9 7 10 7 11 7 12 7 13 7 2 7 ATCR4 7 5 ATCR6 ATCR7 7 8 9 10 7 11 ATCR12 ATCR13 ATCR14 7 15 ATCR16 17 7 18 19 ATCR20 ATCR21 721 7 1 0757 0442 0757 0438 0698 0085 0698 0085 0757 0399 0757 0399 0698 3391 0757 0198 0698 5839 0698 5839 0698 3260 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 1820 0158 08640 60033 2140 0427 2140 0427 2140 0427 2140 0427 2140 0427 2140 0427 1251 3054 1251 1249 1251 1313 0757 0346 08640 60046 0180 1735 0180 1735 0180 0373 0180 2141 0180 0141 0180 1715 0160 2453 0180 1846 0160 2204 0180 0141 0180 1715 0160 2204 0180 2206 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0025 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1901 0033 1250 0835 0490 1080 QTY 35 ub g 20 TABLE
315. F C4 1 8 TO 1622 F C4 1 8 TO 2152 F C4 1 8 TO 1002 F C4 1 8 TO 3161 F C4 1 8 TO 2152 F C4 1 8 TO 4640 F C4 1 8 TO 5621 F C4 1 8 TO 1002 F C4 1 8 TO 101 F C4 1 8 TO 56R2 F C4 1 8 TO 101 F C4 1 8 TO 56R2 F C4 1 8 TO 56R2 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F C4 1 8 TO 1002 F C4 1 8 TO 1472 F C4 1 8 TO 1001 F C4 1 8 TO 2610 F C4 1 8 TO 10R0 F C4 1 8 TO 10R0 F C4 1 8 TO 1001 F C4 1 8 TO 1963 F C4 1 8 TO 3481 F ET50X202 MF4C1 8 TO 6191 F C4 1 8 TO 3161 F C4 1 8 TO 2152 F C4 1 8 TO 2371 F ET50X202 C4 1 8 TO 4640 F C4 1 8 TO 5621 F 4 1 8 0 101 4 1 8 0 101 C4 1 8 TO 1002 F C4 1 8 TO 101 F C4 1 8 TO 101 F C4 1 8 TO 1472 F PME65 1 2 TO 2611 F PME65 1 2 TO 2611 F C4 1 8 TO 56R2 F C4 1 8 TO 56R2 F C4 1 8 TO 601 F C4 1 8 TO 601 F C4 1 8 TO 1002 F C4 1 8 TO 1002 F 5080 1718 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 52 10939 62 52 10939 62 08640 60149 08640 20218 08640 20205 1430 0763 08640 20084 3030 0196 3030 0007 C4 1 8 TO 7151 F C4 1 8 TO 2152 F C4 1 8 TO 2153 F MF7C1 2 TO 2404 F C4 1 8 TO 7151 F MODEL 8640B OPTION 004 REFERENCE HP PART QTY DESIGNATION NUMBER A11A1R6 0757 0199 11 1 7 0698 3454 A11A1R8 0698 5903 11 151 08640 60108 1 3100 3081 1 6 3 DESCRIPTION REPLACEABLE PARTS MFR CODE RESISTOR 21 5K 1 RESISTOR 215K 1 125W TUBULA 24546 125W F TUBULAR 16299 RESISTOR 2 4N 1 5W F TUBULAR 19701
316. F C4 1 8 TO 422R F BWH2 1R0 J BWH2 1R0 J C3 1 8 TO 2611 G 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 0360 1514 723BE 723BE SZ 10939 182 52 10939 266 5211213 278 52 10939 386 52 10939 5 MODEL 8640B OPTION 004 REFERENCE DESIGNATION A20VR6 A20XF1A A20XF1B A20XF2A A20XF2B A21 A22 22 1 A22C2 A22C3 22 4 22 5 22 6 22 7 22 8 A22CR1 A22CR2 A22CR3 A22CR4 A22CR5 A22CR6 A22DS1 A22DS2 A22F1 A22F2 A22MP1 A22MP2 A22Q1 A22Q2 A22Q3 A2204 A22R1 A22R2 A22R3 A22R4 A22R5 A22R6 A22R7 A22R8 A22R9 A22R10 A22R11 A22R12 A22R13 A22R14 A22R15 A22R16 A22R17 A22R18 A22R19 A22R20 A22R21 A22R22 A22R23 A22R24 A22R25 A22R26 A22R27 A22R28 22 1 22 2 22 3 22 4 22 5 1902 0049 1251 2313 1251 2313 1251 2313 1251 2313 08640 601771 0180 0229 0160 3534 0160 0158 2 0180 0058 2 0180 0229 0160 3534 0160 0158 0180 0058 1901 0025 1901 0159 1901 0050 1901 0025 1901 0050 1901 0159 1990 0326 1990 0326 2110 0424 2 2110 0424 4040 0748 1480 0073 4040 0754 2 1480 0073 1884 0012 1854 0232 1200 0173 1854 0232 1200 0173 1884 0012 0698 0085 0757 0280 0698 3154 0757 0401 0698 0084 2 0757 0438 2100 3123 0683 0275 2 0698 3439 0757 0397 0698 3447 0811 1668 2 0757 0278 0698 0085 0757 0280
317. F TUBULAR RESISTOR 12 1 OHM 2 05W F TUBULAR RESISTOR 422 OHM RESISTOR 422 OHM 2 05W F TUBULAR 2 05W F TUBULAR RESISTOR 82 5 OHM 1 125W F TUBULAR RESISTOR 133 OHM RESISTOR 10 OHM 1 RESISTOR 5 11K 1 RESISTOR 10 OHM 1 RESISTOR 5 11K 1 RESISTOR 10 OHM 1 RESISTOR 5 11K 2 RESISTOR 5 11K 2 RESISTOR 196 OHM RESISTOR 316 OHM 1 125W F TUBULAR 5W F TUBULAR 125W F TUBULAR 5W F TUBULAR 125W F TUBULAR 5W F TUBULAR 05W F TUBULAR 05W F TUBULAR 1 125W F TUBULAR 1 125W F TUBULAR RESISTOR 12 1 OHM 1 125W F TUBULAR RESISTOR 422 OHM RESISTOR 422 OHM RESISTOR 10K 1 RESISTOR 10 OHM 1 RESISTOR 10K 1 RESISTOR 2 61K 1 NOT ASSIGNED RESISTOR 1 47K 1 RESISTOR 215K 1 RESISTOR 10K 1 RESISTOR 1K 1 1 RESISTOR 1K 1 1 RESISTOR 511 OHM TRANSFORMER RF CODE TRANSFORMER RF TRANSFORMER RF TRANSFORMER RF TRANSFORMER RF TRANSFORMER RF 1 TERMINAL SLDR ST TERMINAL SLDR ST TERMINAL SLDR ST TERMINAL SLDR ST IC LIN AMPLIFIER IC DGTL MC 1013P IC DGTL MC 1013P IC DGTL MC 1013P IC DGTL MC 1013P IC DGTL SN75 4518 IC DGTL MN 1010P IC DGTL MC 1010P IC DGTL MC 1010P IC DGTL GATE IC LIN AMPLIFIER IC DGTL COUNTER IC DGTL GATE IC DGTL COUNTER IC DGTL GATE IC DGTL FLIP FLOP IC DGTL MC 1010P IC DGTL MC 1027P IC DGTL MC 1010P IC DGTL MC 1013P DIODE 2NR 2 37V 5 CABLE COAX 50 OHM CABLE COAX 50 OHM CABLE COAX 50 OHM CABLE COAX 50 OHM ABLE COA
318. F receivers The Signal Generator covers the frequency range 500 kHz to 512 MHz 450 kHz to 550 MHz with band over range and can be extended to 1100 MHz with an external doubler An optional variable audio oscillator is also available to extend the CW output range of the generator down to 20 Hz 1 15 This solid state generator has an output level range of 15 to 142 dBm 1 3V to 0 018 pV that is calibrated and metered The output is leveled to within 0 5 dB from 108 to 336 MHz and within 0 75 dB across the full frequency range of the instrument 1 16 The generator also provides AM FM and pulse modulation for a wide range of receiver test applications AM and FM can be performed independently or simultaneously in either the internal or external modes This modulation is calibrated and metered for direct readout under all operating conditions External pulse modulation is also available 1 17 For avionics testing VOR ILS an external audio generator is required to provide the com posite modulation When used with a suitable external audio generator the Option 004 has flat AM response and minimum phase shift from 30 Hz to 10 kHz as well as constant group delay between 9 kHz and 11 kHz for accurate VOR and ILS testing A front panel jack also provides a very accurate demodulated audio signal AC DC 0 1 Vrms or AC only 0 5 Vrms for precise AM settings e g Bendix RVG 33A VOR Audio Generator RIG 32A ILS Audio Gener
319. FF and INT The envelope of the audio signal displayed on the oscilloscope should stabilize within a few seconds after AM is switched to INT 16C If distortion or AM stability is incorrect adjust AI 1R28 reduce resistance for less distortion or cw increase resistance for better stability NOTE Adjustment is correct when distortion and stability areas described in steps 16a and 16b Measurement results recorded in preceding steps may have changed perhaps beyond stated limits after reajust ing 11 28 Model 8640B Option 004 08640 90073 CHANGE 14 Cont d Page 6 4 Table 6 3 Change part number for A3MP9 to 08640 20267 Delete NOTE Transistor cap 08640 20267 is the single recommended replacement for 9 and in instruments with serial number prefixes below 1544A Table 6 3 Change A11R28 to 2100 2574 RESISTOR VAR TRMR 500 OHM 107 Service Sheet 9A schematic Delete asterisk at Al1R28 and change the symbol to a potentiometer whose wiper is connected to the junction of A11R28 and ATIRTI CHANGE 15 Pages 6 15 and 6 17 Table 6 3 Change A8A3R10 and R17 to 0698 0083 RESISTOR FXD 1 96K 1 0 125W TUBULAR Change A8A3U10 Ull U16 and 017 to 1820 1490 Change A8A3U13 014 and 015 to 1820 1429 NOTE The parts listed above are the recommended replacements for A8A3R10 R17 U1O Ull and U13 thru U17 in instruments with serial number prefixes below 1545A P
320. FREQUENCY TUNE As specified FINE TUNE Centered OUTPUT LEVEL Switches 0 dBm 0 0 OUTPUT LEVEL Vernier CAL RF ON OFF 2 Set FREQUENCY TUNE to 356 MHz approached from low frequency band end 256 MHz adjust adjustment A3A4R2 until the relays in the 10 assembly just actuate When the relays actuate they make a faint but audible clicking 3 Tune FREQUENCY TUNE one turn ccw and then cw until relays actuate The frequency at actuation should be 355 357 MHz 4 Tune FREQUENCY TUNE from 256 to 512 MHz The generator s panel meter should read 0 dBm through the entire frequency range 5 37 RF OSCILLATOR END STOP ADJUSTMENT REFERENCE Service Sheets 5 6 and 7 DESCRIPTION This procedure describes the adjustment of the high and low frequency end stops of the RF Oscillator A3 Slight adjustment of the end stops may be necessary when the RF Oscillator or Fine Tune assembly has been repaired or replaced No special tools are required 5 25 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 37 RF OSCILLATOR END STOP ADJUSTMENT Cont d Normally the adjustment can be made with the RF Oscillator in place However if the oscillator has already been removed the adjustment is easier if the Connector Board Assembly A3A4 is plugged in and the oscillator set into place with the front resting on the
321. Fuse HP 2110 0094 Demod Cal Labels HP 7120 4244 1 67 The rack mounting kit the cable and the fuses are fully described Section II 1 68 The following accessories are mounted inside the instrument s chassis and are available for adjustment and repair for more information see and Combination Wrench HP 5001 0135 Spare fuses for power supply circuit boards 30 pin Extender Board HP 08640 60036 1 69 EQUIPMENT AVAILABLE 1 70 Fuseholder The HP Model 11509A Fuse holder attaches to the RF OUT jack and prevents accidental damage to the generator s output atten uator by externally applied R F It is primarily used when testing transceivers CAUTION The fuseholder may not protect the out put amplifier against a fast pulse of reverse power on the top two ranges of the OUTPUT LEVEL 10 dB switch 1 71 Termination The HP Model 11507A Termi nation maintains the generator s output level cali bration when the output is connected to load impedances other than 50 ohms It can provide source impedances of 25 and 5 ohms and it can simulate a broadcast band dummy antenna The frequency range is 50 kHz to 65 MHz Model 8640B Option 004 1 72 75 Ohm Adapter The HP Model 11687A 50 to 75 Ohm Adapter connects to the generator s out put to provide a source impedance of 75 ohms 1 73 Doubler The HP Model 11690A Doubler extends the usable frequency range of the gener ator one octave to 1024 MHz actually to
322. GES TO EQUIPMENT TECHNICAL PUBLICATIONS SOMETHING WRONG WITH THIS PUBLICATION FROM PRINT YOUR UNIT S COMPLETE ADDRESS THEN JOT DOWN THE DOPE ABOUT IT ON THIS FORM CAREFULLY TEAR IT OUT FOLD IT AND DROP IT PUBLICATION NUMBER PUBLICATION DATE PUBLICATION TITLE Signal Generators TM 11 6625 2780 144P 31 Dec 80 G 1112 V 1 U and 50 1112 7 2 0 EXACT PIN POINT WHERE 1715 IN THIS SPACE TELL WHAT IS WRONG PARA eee ro res TABLE AND WHAT SHOULD BE DONE ABOUT IT GRAPH NO NO PRINTE NAME GRADE R ULE ANC TELEPHONE NUMREP SIGN HERE D FORM 2028 2 PREVIOUS EDITIONS PS IF YOUR OUTFIT WANTS KNOW ABOUT YOUR git 79 OBSOLETE RECOMMENDATION MAKE CARBON COPY OF THIS AND GIVE 17 TO HEADQUARTERS FILL IN YOUR UNIT S ADDRESS FOLD BACK DEPARTMENT OF THE ARMY POSTAGE AND FEES PAID DEPARTMENT OF THE ARMY U S MAIL OFFICIAL BUSINESS 095 314 PENALTY FOR PRIVATE USE 300 Commander US Army Communications and Electronics Materiel Readiness Command ATTN DRSEL ME MQ Fort Monmouth New Jersey 07703 FOLD BACK REVERSE OF DA FORM 2028 2 GUN ee ALLOG Sy DEPARTMENT OF THE ARMY US ARMY AG PUBLICATIONS CENTER 1655 WOODSON ROAD ST LOUIS MISSOURI 63114 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE 300 This fine document Was brought to you by me Liberated Manuals free army an
323. Hi 180 lt 5 PHASE LOCK TUNE 190 J io 1820 0174 mE LOCK EXPAND SWITCHING COUNTER PHASE LOCK CIRCUITS QFTION Figure 8 69 Counter Phase Lock Circuits Schematic Diagram Figure 8 68 P O A8A2 Counter Lock Board Assembly Component Locations 1 SERVICE SHEET 22 PRINCIPLES OF OPERATION General The power supply assemblies provide five regulated supply voltages The characteristics and locations of each regulator are as follows Assembly Service Sheet No Supply Voltage Limiting Voltage Regulation Current Number 1A A20 22 2 25 20 1 15 A18 22 a With a temperature coefficient of 4 2 mV C Input Voltage A12 and 14 Main ae power enters the A14 Line Power Module which contains the primary line fuse an RFI filter and a printed circuit card switch which matches the transformer primary windings to the appropriate line voltage Power transformer T1 has a separate secondary winding for each regulator The A12 Rectifier Assembly contains five full wave rectifiers 5 2V Regulator A20 The 5 2V Regulator is a linear series type with current foldback for over current protection and a crowbar for over voltage protection The Voltage Regulator amplifier U1 compares the outpu
324. Hz FREQUENCY TUNE 110 MHz OUTPUT LEVEL Switches 10 dBm 10 0 OUTPUT LEVEL Vernier CAL RF ON OFF Demodulation Amplifier Troubleshooting Component Test Conditions and Normal Indication If Indication or Circuit Control Settings is Abnormal BUFFER Initial conditions and set AMPLIFIER tings A26A8 SCALING Initial conditions and set AMPLIFIER tings Set AC DC switch A26A8 Al to DC position Set AC DC switch S1 to AC position 8 48 2 4 with 1 5 Vp p Check A26A8UI and at TP1 associated circuitry 1 4 Vdc with 1 4 Vp p Check A26A8U2 and at TP3 associated circuitry 0 Vdc with 7 0 Vp p at Check A26A8U2 and TP3 associated circuitry Model 8640B Option 004 Service A9 P O AZG AMAG AND RF AMPLIFIER ASSY 03640760058 L L o ee B REFERENCE DESIGNATIONS P O P1 XA26A8 P O S2 Component Locations for 9 Assembly are Service Sheets 6 and 8 P O A26A5 RISER ASSY 9 0 A26A6 AM MOTHER 08640 60068 BOARD ASSY 08640 60067 A26A8 DEMODULATION AMPLIFIER ASSY 08640 60069 _ _____ ULATION AMPLIFIER ASSY 08640 60060 ___ 7 XAZ6A6 22277 EMO _ gt ee DEMOD OUT DEMOD 9 4147 0 OUTPUT P O 15 619 gt zo 3 P O 26 5 A26A5 NO PREFIX P O XA26A6 BUFFER AM
325. Hz BW is 30 dB The average noise level on the display should be 20 dB below the top graticule line ie 130 dB below carrier 20 dB NOTE If the test generator appears to be out of specification check for excessive noise in the test setup by disconnecting the test generator The noise level on the analyzer s display should decrease at least 10 dB See Hewlett Packard Application Note 150 4 Spectrum Analysis Noise Measurements 4 29 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 23 RESIDUAL AM TEST SPECIFICATION Residual AM Averaged rms Post detection Noise Bandwidth 300 Hz to 3 kHz 20 Hz to 15 kHz gt 85 dB down gt 78 dB down DESCRIPTION An rms voltmeter is calibrated with a measured amount of amplitude modulation from the Signal Generator Then the AM is removed and the generator s residual AM is read directly from the voltmeter See Table 4 1 Recommended Test Abridgements MODEL 8640B OPTION 004 RMS VOLTMETER 9 0 9 6 Neral RF OUT 40 dB AMPLIFIER INPUT OUTPUT DETECTOR 3 kHz LPF TEE STEPA MET 500 LOAD 15 kHz LPF __ STEP 1 ir 2 Figure 4 8 Residual Test Setup EQUIPMENT RMS Voltmeter HP 3400A Detector HP 8471A 3 kHz Low Pass CIR Q TEL 5 Pole 15 kHz Low Pass Filter CIR Q TEL 7 Pole 40 dB Amplifier s s s s s s
326. IATION VERNIER RANGE FREQUENCY TUNE FINE TUNE OUTPUT LEVEL SWITCHES OUTPUT LEVEL VERNIER RF ON OFF go Eo ee INT RANGE OS TO T MHz PEAK DEVIATION 10 kHz 5 12 PAD AB DEVIATION AND RANGE SWITCH ASSY a nO REDUCE PEAK DEVIATION LAMP N id FM F 3 FMINPUT 11 Vide THEM 1 1 Vii TO MFTER REDUCE FM VERNIER LAMP ON oat SCALE LAMP 1426 CONTROL 3 Figure 8 19 FM Circuits and RF Oscillator Block Diagram 8 91 SERVICE SHEET 3 PRINCIPLES OF OPERATION Divider Filters Service Sheets 10 and 11 Except for the 256 512 MHz and the doubler frequency range the RF signal from the Divider Filter Buffer Amplifier Service Sheet 2 is routed through a series of binary frequency dividers 1 2 by slide switches on the filter section of the A10 Divider Filter Assembly The RF signal is divided to the selected range This is also illustrated in simplified logic diagran Figure 8 41 The divided signal passes through the Modulator Preamplifier the Modulator and then to the RF Filters The filters remove unwanted harmonics from the signal which is approximately a square wave after being divided The upper frequency ranges have two filters per range one for the lower half Low Band Filters and one for the upper half High
327. IER i LEVEL FREQUENCY E STEP 11 DIVIDER FILTER ASSY _ D u m _ _ _ Q i ATTENUATOR ATTENUATOA Lm 2 RE DIVIDER AY 9 2dBm 7 2 MHz SQUARE WAVE MEASURED WITH AGC LODP OPEN WHICH SETS MODULATOR AT MINIMUM ATTENUATION DETECTOR BUFFER AMPLIFIER SAMPLE AND HOLD i TAV SQUARE WAVE AT 7 kHz t PL ee ee paid ee _ FAD MODULATOR ASSY i RN our AMINPUT 7 SQUARE WAVE PREAMPLIFIE 100 Hab 1 DE BY 2 4 8 18 32 84 128 266 OR 512 256 5124 963 1 1 dBm TATE 12 kHz SQUARE WAVE iter service SET CONTROLS FOLLOWS UNLESS OTHERWISE SPECIFIED METER FUNCTION LEVEL COUNTER MODE EXPANG OFF GI FREQUENCY TUNE FINE TUNE OUTPUT LEVEL SWITCHES OUTPUT LEVEL VERNIER RF ON OFF 2 0 0 2 Vdc MODULATION FREQUENCY 2 7 METER FUNCTION aM MODULATION SET TO 707 mVrma MEASURED AT 1000 10 METER FUNCTION LEVEL OUTPUT LEVEL SWITCHES ANG SET TO IX THEN 253 my dc MEASURED AT 9000 1 BO 010 SCALE LAMP ON 800 0 3 SCALE ON FOR 253 mide
328. ING 3 5NS 5V 60MA 28480 1910 0022 A26A2CR17 1901 0040 DIODE SWITCHING 2NS 30V 50MA 28480 1901 0040 A26A2CR18 1910 0022 DIODE SWITCHING 3 5NS 5V 60MA 28480 1910 0022 A26A2K1 NOT ASSIGNED A26A2L1 9100 1641 4 COIL FXD MOLDED RF CHOKE 240UH 5 24226 15 243 A26A2L2 9100 1641 COIL FXD MOLDED RF CHOKE 240UH 5 24226 15 243 A26A2L3 9100 1620 COIL FXD MOLDED RF CHOKE 15UH 10 24226 15 152 A26A2MP1 4040 0749 EXTRACTOR PC BOARD BROWN 28480 4040 0749 1480 0073 PIN DRIVE 0 250 LG 00000 OBD A26A2MP2 4040 0752 EXTRACTOR PC BOARD YELLOW 28480 4040 0752 1480 0073 PIN DRIVE 0 250 LG 00000 OBD A26A2Q1 1854 0221 TRANSISTOR NPN DUAL 200 10MV VBE 28480 1854 0221 A26A202 1854 0404 TRANSISTOR NPN SI TO 18 PD 360MW 28480 1854 0404 26 203 1853 0034 TRANSISTOR PNP SI CHIP TO 18 PD 360MW 28480 1853 0034 26 204 1853 0034 TRANSISTOR PNP SI CHIP TO 18 PD 360MW 28480 1853 0034 A26A2Q5 1854 0404 TRANSISTOR NPN SI TO 18 PD 360MW 28480 1854 0404 26 206 1854 0404 TRANSISTOR NPN SI TO 18 PD 360MW 28480 1854 0404 A26A2Q7 1854 0404 TRANSISTOR NPN SI TO 18 PD 360MW 28480 1854 0404 A26A208 1853 0034 TRANSISTOR PNP SI CHIP TO 18 PD 360MW 28480 1853 0034 26 209 1853 0034 TRANSISTOR PNP SI CHIP TO 18 PC 360MW 28480 1853 0034 A26A2R1 0757 0465 6 RESISTOR 100K 1 125W F TUBULAR 24546 C4 1 8 TO 1003 F A26A2R2 0757 0440 RESISTOR 7 5K 1 125 F TUBULAR 24546 C4 1 8 TO 7501 F A26A2R3 0757 0442 RESISTOR 10K 1 125W F TUBULAR 24546 C4 1 8 TO 1002 F A26A2R4 0757 0442 RES
329. ISTOR 10K 1 125W F TUBULAR 24546 C4 1 8 TO 1002 F A26A2R5 0698 3155 RESISTOR 4 64K 1 125W F TUBULAR 16299 C4 1 8 TO 4641 F A26A2R6 0757 0442 RESISTOR 10K 1 125W F TUBULAR 24546 C4 1 8 TO 1002 F A26A2R7 0757 0440 RESISTOR 7 5K 1 125W F TUBULAR 24546 C4 1 8 TO 7501 F A26A2R8 0757 0422 RESISTOR 909 OHM 1 125W TUBULAR 24546 C4 1 8 TO 909R F A26A2R9 0757 0421 4 RESISTOR 825 OHM 1 125W TUBULAR 24546 C4 1 8 TO 825R F A26A2R10 0757 0439 1 RESISTOR 6 81K 1 125W F TUBULAR 24546 C4 1 8 TO 6811 F A26A2R11 0757 0442 RESISTOR 10K 1 125W F TUBULAR 24546 C4 1 8 TO 1002 F A26A2R12 0757 0442 RESISTOR 10K 1 125W F TUBULAR 24546 C4 1 8 TO 1002 F A26A2R13 0757 0401 RESISTOR 100 OHM 1 125W F TUBULAR 24546 C4 1 8 TO 101 F A26A2R14 0757 0421 RESISTOR 825 OHM 1 125 F TUBULAR 24546 C4 1 8 TO 825R F A26A2R15 0757 0438 RESISTOR 5 11K 1 125W F TUBULAR 24546 C4 1 8 TO 5111 F MODEL 8640B OPTION 004 REFERENCE DESIGNATION A26A2R16 A26A2R17 A26A2R18 A26A2R19 A26A2R20 A26A2R21 A26A2R22 A26A2R23 A26A2R24 A26A2R25 A26A2R26 A26A2R27 A26A2R28 A26A2R29 A26A2R30 A26A2R31 A26A2R32 A26A2R33 A26A2R34 A26A2R35 A26A2R36 A26A2R37 A26A2R38 A26A2R39 A26A2TP1 A26A2TP2 A26A2TP3 A26A2TP4 A26A2TP5 A26A2TP6 A26A2TP7 A26A2TP8 A26A2U1 A26A2U2 A26A2U3 A26A2VR1 A26A3 26 1 A26A3C2 A26A3C3 A26A3C4 A26A3C5 A26A3C6 26 1 A26A3CR2 A26A3CR3 A26A3CR4 A26A3CR5 A26A3CR6 A26A3CR7 A26A3CR8 A26A3J1 A26A3L
330. ISTOR 4 22K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 42 2K 1 125W F TUBULAR RESISTOR 13 3K 1 125W F TUBULAR RESISTOR 464 OHM 1 125W F TUBULAR RESISTOR 1 96K 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 1 96K 1 125W F TUBULAR TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD IC DGTL COMPARATOR ANALOG IC DGTL SN54 00 N GATE IC DGTL SN74 123 N MULTIVIBRATOR DIODE ZNR 8 25V 5 DO 7 PD 4W MODULATOR ASSY CAPACITOR FXD 1UF 10 100WVDC CER CAPACITOR FXD 1UF 10 100WVDC CER CAPACITOR FXD 22PF 5 500MVCC TI DIOX CAPACITOR FXD 22PF 5 500WVDC TI DIOX CAPACITOR FXD 22PF 5 500MVDC TI DIOX CAPACITOR FXD 22PF 5 500MVDC TI DIOX MATCHED DIODE SET INCL A26A3CR2 8 NSR NSR PART OF A26A3RC1 NSR PART OF A26A3CR1 NSR PART OF A26A3CR1 NSR PART OF A26A3CR1 NSR PART OF 26 1 NSR PAR OF A26A3CR1 NSR PART OF A26A3CR1 CONNECTOR RF SMC M SGL HDLE RR COIL FXD MOLDED RF CHOKE 15UH 10 COIL FXD MOLDED RF CHOKE 4 7UH 10 RESISTOR 511 OHM 2 05W F TUBULAR RESISTOR 261 OHM 1 125W F TUBULAR RESISTOR 261 OHM 1 125W F TUBULAR RESISTOR 511 OHM 1 125W F TUBULAR RESISTOR 511 OHM 1 125W F TUBULAR BALUN ASSY BALUM ASSY CONNECTOR 1 CONT SKT 033 DIA BOARD ASSY AGC AMPLIFIER CAPACITOR FXD 10 1
331. Internal Reference Drift Rate Stability Test Setup EQUIPMENT Frequency Counter 222020 HP 5327C Option 003 Temperature Controlled Chamber Statham Model 325 Variable Voltage Transformer GR W5MT3A Coaxial Short N Male HP 11512A Quartz Oscillator pote ke oe HP105B Digital to Analog Converter ss HP 581A Option 002 Recorder for D A Converter HP 680 PROCEDURE l Connect equipment as shown in Figure 4 34 dfter setting Signal Generator s controls as follows 4 90 TIME BASE REF INT EXT on rear panel 2 cw amp w a INT COUNTER MODE LOCK Off AM de ex e UE me dy a 4 e Cu FM e s s o s s PEAK DEVITION poses oe sey fy i gt gt gt 5 kHz PEAK DEVIATION Vernier 2 4 4 24 Fully CW RANGE ees m 0s s s 05 1 MHz OUTPUT LEVEL Switches we combo 16 dBm OUTPUT LEVEL Vernier RF ON OFF s s a a Set variable voltage transformer to nominal voltage set on generator s line power module i e 100 120 220 or 240 Vat Set temperature controlled chamber for 25 C Allow equipment to warm up for two hours Set frequency counter so that it s using its internal reference oscillator Set counter to read frequency directly i e not divided down Use 1s gat
332. JUSTMENT REFERENCE Service Sheets 6 7 and 8 DESCRIPTION The switches are adjusted so that the FM gain switch i e A9S3 the switch that is controlled by both the peak deviation and the frequency range switch is correctly positioned This procedure should be performed whenever the A9 assembly has been disassembled PROCEDURE 1 Set RANGE and PEAK DEVIATION switches fully cw Loosen setscrews in the knobs and position RANGE switch knob so that 512 1024 MHz is under the cursor on front panel Position PEAK DEVIATION switch knob so that 5 12 MHz is under the cursor on front panel Tighten setscrews 2 Loosen locking screw on gain switch 4953 shaft see exploded view in Section Rotate shaft until rotor tooth on the front of the front wafer A9S3AF 3 1 2 is centered under clip with 94 wire white yellow Tighten locking screw 3 Rotate RANGE and PEAK DEVIATION switches through all of their positions one at a time Check that tooth is adequately centered under all of the clips when they are approached from either direction there is some backlash If not readjust the shaft until it is 4 Perform Range Switch Adjustment paragraph 5 34 5 34 RANGE SWITCH ADJUSTMENT REFERENCE Service Sheet 10 DESCRIPTION The frequency at RF OUT is monitored with a frequency counter The divider filter cams are positioned so that the frequency at RF OUT agrees with the frequency indicated on the generator s readout The RANGE
333. K Off Source INT AM OFF FM OFF RANGES gi ci RB Apatite dg 256 512 MHz FREQUENCY TUNE 512 MHz OUTPUT LEVEL 10 dB 10 dBm OUTPUT LEVEL 1 OUTPUT LEVEL Vernier CAL RF ON OFF 2 Set voltmeter so that it can measure 100 mV Adjust the stub for a minimum indication on volt meter Note the reading on the voltmeter mV 3 Adjust the stub for a maximum indication on voltmeter The voltmeter should indicate less than twice the voltage noted in Step 2 mV 4 Set generators OUTPUT LEVEL 10 dB switch one step ccw to O dBm Set voltmeter so that it can measure 30 mV Adjust the stub for a minimum indication on voltmeter and note this reading mV 5 Adjust the stub for a maximum indication on voltmeter The voltmeter should indicate less than 1 3 times the reading noted in step 4 mV 6 Set generators OUTPUT LEVEL 10 dB switch one step ccw to 10 dBm Set voltmeter so that it can measure 10 mV Adjust the stub for a minimum indication on voltmeter and note this reading mV 7 Adjust the stub for a maximum indication on voltmeter The voltmeter should indicate less than 1 3 times the reading noted in step 6 mV 8 If desired repeat at other frequencies between 256 and 512 MHz 4 48 NOTE The steps given above effectively check VSWR at all settings of the output attenuators see Service Sheet 13 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 29 OUTPUT IMPEDANCE TEST Broadband SPECIFICATION Impedan
334. L Switches 30 dBm OUTPUT LEVEL Vernier CAL RF ON OFF ONT 2 Set spectrum analyzer s center frequency to 113 MHz resolution bandwidth to 300 kHz input attenuation to 0 dB and vertical scale to linear Set frequency span to zero and tune spectrum analyzer to peak the trace on the CRT NOTE Display Smoothing video filter must be off 8 Set test oscillator output level to approximately 0 5 Vrms at 90 Hz Set Signal Generator s AM control to DC and adjust MODULATION control to give 5096 AM as read on the panel meter 4 72 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 40 AM FLATNESS TEST Cont d 4 Adjust spectrum analyzer vertical sensitivity to give a digital voltmeter reading of 200 mVrms 5 Slowly increase test oscillator frequency to 150 Hz and note maximum amplitude variation on digital voltmeter Maximum variation should be less than 1 2 mV 0 05 dB 198 8 7 2012 6 Set Signal Generator frequency to 332 MHz and repeat steps 2 to 5 7 Set Signal Generator frequency to 113 MHz and repeat steps 2 to 5 except vary test oscillator frequency from 9 to 11 kHz 4 41 PULSE MODULATION TEST SPECIFICATION Pulse Modulation Frequency Rise and Fall Pulse Repetition 50 Hz to 50 kHz 50 Hz to 100 kHz 50 Hz to 250 kHz 50 Hz to 500 kHz Rate Pulse width Minimum for Level Accuracy within 1 dB 10 us 5 us 2 us of cw
335. LD BE DONE ABOUT IT For item 2 change the NSN to read 5835 00 134 9186 Reason Accuracy Identify the cover on the junction box item no 5 Reason It is a separate item an not called out on figure 19 Add the cover of the junction box d an item in the listing for figure 19 Same as above 999 1776 SIGN HERE ee PS IF YOUR OUTFIT WANTS TO KNOW AB RECOMMENDATION MAKE A CARBON COPY OF THIS AND GIVE TO YOUR HEADQUARTERS T YOUR PEER VONG 115 RECOMMENDED CHANGES EQUIPMENT TECHNICAL PUBLICATIONS SOMETHING WROMG wire THis PUBLICATION FROM PRINT YOUR UNIT S COMPLETE ADDRESS THEN JOT DOWN THE DOPE ABOUT IT ON THIS FORM CAREFULLY TEAR IT OUT FOLD IT AND DROP IT PUBLICATION NUMBER PUBLICATION DATE PUBLICATION TITLE Signal Generators TM 11 6625 2780 31 80 SG 1112 V 1 U and SG 1112 V 2 U BE EXACT PIN PONT WHERE 1715 IN THIS SPACE TELL WHAT IS WRONG PARA eee rame AND WHAT SHOULD BE DONE ABOUT IT GRAPH NO NO PRINTE NAMF GRADE OR TLE ANT TELEPHONE NUMRER SIGN HERE D FORM 2028 2 PREVIOUS F DPTIONS PS 4F YOUR OUTFIT WANTS TO KNOW ABOUT YOUR F 22 29 ARE GBSOLETE RECOMMENDATION MAKE A CARBON COPY OF THIS AND GIVE IT YOUR HEADQUARTERS FILL IN YOUR UNIT S ADDRESS FOLD BACK DEPARTMENT OF THE ARMY POSTAGE AND FEES PAID 2 DEPARTMENT OF THE ARMY OFFICIAL BUSINESS DOOSI PENALTY FOR PRIVATE USE 300 Commander
336. LDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD IC LIN AMPLIFIER IC DGTL LM311H COMPARATOR IC DGTL SN74 02 N GATE IC DGTL SN74 06 N INVERTER ANALOG DIODE ZNR 10V 5 DO 7 PD 4W TC 06 DIODE ZNR 14 7V 5 DO 7 PD 4W BOARD ASSY AM RISER CONNECTOR PC EDGE 15 CONT WIRE WRAP BOARD ASSY AM MOTHER CONNECTOR PC EDGE 15 CONT DIP SOLDER CONNECTOR PC EDGE 15 CONT DIP SOLDER CONNECTOR PC EDGE 15 CONT DIP SOLDER NOT ASSIGNED BOARD ASSY DEMODULATOR AMPLIFIER CAPACITOR FXD 6 8UF 10 35VDC TA CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 6 8UF 10 35VDC TA CAPACITOR FXD 01UF 80 20 100WVDC CER CAPACITOR FXD 6 8UF 10 35VDC TA CAPACITOR FXD 01U 80 20 100MVDC CER EXTRACTOR PC BOARD EXTRACTOR PC BOARD BROWN BLUE RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 178 OHM 1 178 OHM 1 VAR TRMR 10K 1 1K 1 5W F TUBULAR 5W F TUBULAR 1KOHM 10 C 125W F TUBULAR 125W F TUBULAR RESISTOR VAR TRMR 10KOHM 10 C SIDE ADJ RESISTOR 7 5K 1 125W F TUBULAR RESISTOR VAR TRMR 10KOHM 10 C SIDE ADJ RESISTOR 42 2K 1 125W F TUBULAR RESISTOR VAR TRMR 2KOHM 10 C SIDE ADJ MFR CODE 16299 24546 24546 24546 24546 16299 16299 24546 24546 24546 24546 16299 16299 24546 16299 24546 19701 16299 16299 24546 24546 24546 24546 24546 24546 28480 28480 28480 28480 28480 28480 23480 28480 04713 27014 01295 01295 04713 04713 28480 284
337. LLE NJ WHIPPANY NJ PHOENIX AZ CHATSWORTH CA MOUNTAIN VIEW CA CR ANFORD NJ WATERTOWN MA SANTA ANA CA OOVER NH MOUNTAIN VIEW CA RALEIGH NC MINERAL WELLS TX NORTH HAVEN CT GOWANDA NY BRAOFORD PA INOIANAPOLIS IN NEW ROCHELLE NY CHICAGO IL SANTA CLARA CA PALO ALTO CA SAN DIEGO RIVERSIDE CA NORTH ADAMS MA ST 10015 MO ECKHART IN CHICAGO TL ELK GROVE V ILLAGE IL WILLIMANTIC CT CHICAGO TL BROOKLYN NY PHILADELPHIA PA DES PLAINES IL CRYSTAL LAKE IL ELGIN IL LONG ISLAND CITY NY WARMINSTER PA EL IZABETH NJ DEFIANCE OH BROOKLYN NY BROOKFLELO MA OGALLALA NE GLENDALE CA ZEL WOOD COLUMBUS NE ST MARYS PA CHICAGO IL CEDAR KNOLLS NJ IRVINGTON NJ MAMARONECK NY PART NUMBER AlH CB1055 CB27G5 CB3355 CB47G5 CB8245 CB8245 Jg 15F481F0300WV1C DM74L90N DV11PR18A GF126 0018 LM301AH LM302H LM311H MC1010P MC1013P MC1027P MC7812CP SN7400N SN7402N SN7404N SN7405N SN7406N SN7408N SN74123N SN7432N SN7474N SN7490N SN7496N SN75451BP SR1358 4 5211213 191 PART NUMBER NATIONAL STOCK NUMBER TABLE 6 5 CROSS REFERENCE INDEX FSCM 87034 72136 27014 73899 79727 27014 27014 04713 04713 04713 04713 04713 04713 NATIONAL STOCK NUMBER 6240 00 951 3376 5905 00 116 8554 5905 00 909 1672 5905 00 402 4264 5905 00 126 6705 5905 00 244 6934 5905 00 968 6140
338. MOD OSC PIN 8 10K 10K 5110 20V 20V Alt PREAMPLIFIER 86408 OPTION O04 1323A A13 REFERENCE DESIGNATIONS WITHIN OUTLINED ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER e g RI OF ASSEMBLY IS AIRI DESIGNATIONS OF OTHER COMPONENTS COMPLETE AS SHOWN Component Locations for A13 Assembly are on Service Sheet 25 GND 2 Ca lt lt g PULSE CODE Li 2 Oe A13 A26A2 Figure 8 51 AM Preamplifier Schematic Diagram 8 47 SERVICE SHEET 15 PRINCIPLES OF OPERATION RF ON OFF Switch The RF ON OFF switch S2 may be wired to turn both RF Oscillator and Modulator off or to turn only the Modulator off The RF ON OFF function may easily be changed to either con figuration by following the instructions on Service Sheet 5 Demodulation Amplifier A26A8 Buffer Amplifier U1 is internally connected as a voltage follower The output of Ul drives the Scaling Amplifier U2 which is connected in an inverting configuration With S1 in the AC position R8 and R9 form the feedback path and set the gain of the amplifier such that 1007 AM produces 5 Vrms at DEMOD OUTPUT R6 provides adjustment to remove the dc component of the Detector output at U2 pin 6 With S1 set to DC RIO
339. MSR PART OF A8A3S1A NSR PART OF A8A3S1A TERMINAL SLDR STUD IC DGTL SN74 00 N GATE IC DGTL SN74 74 N FLIP FLOP IC DGTL SN74 96 N REGISTER IC DGTL SN74 08 N GATE IC DGTL SN74 32 N GATE IC DGTL SN74 32 N GATE DGTL SN74 04 INVERTER IC DGTL SN74 00 N GATE IC DGTL SN74 00 N GATE IC DGTL DM85L 90N COUNTER IC DGTL DM85L 90N COUNTER IC DGTL SN74 90 N COUNTER IC DGTL DM86L 75N COUNTER IC DGTL DM86L 75N COUNTER IC DGTL DM86L 75N COUNTER IC DGTL DM85L 90N COUNTER IC DGTL DM85L 90N COUNTER DIODE ZNR 14 7V 5 00 7 PD 4W CRYSTAL OSCILLATOR CONNECTOR PC EDGE 15 CONT DIP SOLDER COUNTER DISPLAY ASSY LAMP INCAND BULB Tl 5V LAMP INCAND BULD T 1 5V CONTACT 8 PIN IC SOCKET 40 PIN IC BRACKET MOUNTING BRACKET MOUNTING BRACKET MOUNTING CONNECTOR 11 PIN CONNECTOR 25 PIN TRANSISTOR NPN SI PD 300MW FT 200MHZ RESISTOR VAR 5K 20 SPST SW RESISTOR VAR TRMR 10KMR 20 C TOP ADJ RESISTOR 51 1K 2 05W F TUBULAR NOT ASSIGNED RESISTOR 46 4K 2 05W F TUBULAR CONNECTOR CONT SKT 021 DIA CONNECTOR 1 CONT SKT 021 DIA RISER ASSY CONNECTOR PC EDGE 15 CONT DIP SOLDER PEAK DEVIATION AND RANGE SWITCH ASSY CAPACITOR FXD 56PF 5 300WVDC MICA CAPACITOR FXD 56PF 5 300WVDC MICA CAPACITOR FXD 56PF 5 300WVDC MICA CAPACITOR FXD 56PF 5 300WVDC MICA CAPACITOR FXD 56PF 5 300WVDC MICA NOT ASSIGNED NOT ASSIGNED CAPACITOR FXD 270 5 300WVDC MICA RETAINER RING 125 DIA CAD PLT STL
340. N 2 power meter s controls so that it can measure 15 dBm Connect power sensor to test Signal Generator s RF OUT 3 Set test Signal Generator s RF OUTPUT LEVEL controls and vernier for levels set using generator s panel meter shown in the table below verify that the level is within the specified tolerance Signal Generator R F Level Set with Panel Meter Fully cw 15 dBm 14 dBm 13 dBm 12 dBm 11 dBm 10 dBm 1 step ccw 10 dBm from fully cw 9 dBm 8 dBm 7 dBm 6 dBm 5 dBm 4 dBm 3 dBm 2 dBm 1 dBm 0 dBm Power Meter Reading dBm 16 5 15 5 14 5 13 5 12 5 4 42 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 26 OUTPUT LEVEL ACCURACY TEST Complete Cont d 4 10 11 Disconnect power meter and sensor from generator Connect test generator s RF OUT to the step attenuator as shown in Figure 4 11 Do not change any of the test generator s control settings particularly the OUTPUT LEVEL vernier Set reference signal generator for 515 MHz signal with no AM at 10 dBm Set its modulation controls for external FM de and 640 kHz peak deviation FM vernier at maximum Set the attenuator to 50 dB and the IF attenuator to 40 dB Connect spectrum analyzer to tracking generator Set analyzer s center frequency controls to 3 MHz with the tuning stabilizer on set resolution bandwidth to 10 Hz span width pe
341. N 28480 0403 0157 10 3 0403 0158 2 GUIDE BOARD BLUE 28480 0403 0158 10 4 8160 0226 1 RFI ROUND STRIP ALY 062 0D 28480 8160 0226 10 5 08640 00047 1 SHIELD SPRING 1 28480 08640 00047 10 6 08640 00048 1 SHIELD SPRING 2 28480 08640 00048 10 7 08640 00049 1 SHIELD SPRING 3 28480 08640 00049 10 8 08640 00050 1 SHIELD SPRING 4 28480 08640 00050 10 9 08640 20268 1 CAST COVER D F 28480 08640 20268 10 10 08640 20269 CAST CENTER D F 28480 08640 20269 10 11 2190 0003 WASHER LK HLCL NO 4 115 ID 253 28480 2190 0003 10 12 2200 0101 1 SCREW MACH 4 40 PAN HD POZI REC SST 300 28480 2200 0101 A10MP13 2200 0121 SCREW MACH 4 40 PAN HD POSI REC SST 300 28480 2200 0121 10 14 2200 0147 SCREW MACH 4 40 PAN HD POZI REC SST 300 28480 2200 0147 10 15 2200 0127 1 SCREW MACH 4 40 PAN HD POZI REC 551 300 28480 2200 0127 10 16 2190 0124 2 WASHER LK INTL NO 10 195 IN ID 311 24931 LW101 30 A10MP17 2950 0078 2 NUT HEX DBL CHAM 10 32 THD 067 THK 25 24931 HN100 11 10 18 2200 0129 1 SCREW MACH 4 40 PAN HD POZI REC SST 300 28480 2200 0129 10 19 0361 1071 2 RIVET BLIND DOME HD 0 125 DIA 11815 AAP 4 3 10 1 08640 60204 FILTER ASSY 28480 08640 60204 10 1 1 0160 2055 CAPACITOR FXD 010 80 20 100WVDC CER 28480 0160 2055 A10A1C2 0160 2055 CAPACITOR FXD 01UF 80 20 1001VDC CER 28480 0160 2055 A10A1C3 0160 2055 CAPACITOR FXD 01UF 80 20
342. NEARITY ADJUSTMENT Cont d LINEARITY TRACE Figure 5 12 FM Linearity Display 5 Set linearity circuit s output switch to ref var and the voltage divider switch to 1 This calibrates the display for 1 error in linearity per division 6 Adjust variable phase generator s variable phase output s phase and linearity circuits var level control for the best possible horizontal straight line over center portion of trace 7 Adjust POS SHAPE and NEG SHAPE adjustments A7R12 and A7R41 for the best possible horizontal straight line at both ends of the trace but within one major division or 1 8 Perform the FM Sensitivity Adjustment 5 43 5 42 FM LINEARITY ADJUSTMENT Alternate REFERENCE Service Sheet 7 DESCRIPTION The Signal Generator is modulated with a 1 kHz signal The generators RF output is then demodulated with an FM discriminator and the distortion on the discriminator output is observed with a spectrum analyzer The shaping circuits are then adjusted for minimum distortion across the 0 5 to 1 MHz frequency range See paragraph 5 41 another FM Linearity Adjustment which should be more useful in troubleshooting FM distortion NOTE The preliminary FM Adjustment 5 40 should be made before performing this adjustment 5 38 Model 8640B Option 004 Adjustments ADJUSTMENTS 5 42 FM LINEARITY ADJUSTMENT Alternate cont d MODEL 86408 OPTION 004 DISCRIMINATOR OUTPUT F
343. NGE SWITCH ASSEMBLY A9 Test Repai DIVIDER FILTER ASSEMBLY A10 Test Repai FIXEO FREQUENCY MODULATION OSCILLATOR AII Test Repai RECTIFIER ASSEMBLY A12 Test Reps i MOOULATOR METERING MOTHER BOARD ASSEMBLY 3 Test Repai LINE MOOULE ANO FILTER Al4 Test Repai RISER ASSEMBLY 15 Test Repai FAN MOTOR Al 6 Test Repai POWER SUPPLY MOTHER BOARO ASSEMBLY Al 7 Test Repai REGULATOR AND FAN DRIVER ASSEMBLY A18 Test Repair REGULATOR ASSEMBLY 5 2 V ANO 44 6 V A20 Test Repair REGULATOR ASSEMBLY 20 V ANO 20 V A22 Test Repair SERIES REGULATOR SOCKET ASSEMBLY A24 Test Repair AM AGC AND RF Amptitier ASSEMBLY A26 Test Repair D 3 TM11 6625 2780 14 amp P SECTION III TOOL AND TEST EQUIPMENT REQUIREMENTS FOR SG 1112 V 1 U AND SG 1112 V 2 TOOL OR TEST EQUIPMENT REF CODE 10 11 12 13 14 15 16 17 18 29 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 MAINTENANCE CATEGORY H D H D H D H D H D H D H D H D H D Hb H D H D H D NOMENCLATURE ANALYZER SPECTRUM TS 723D U ANALYZER SPECTRUM IP 1216 U PLUG IN PL 1387 U PLUG IN PL 1388 U PLUG IN PL 1399 U PLUG IN PL 1406 U COUNTER ELECTRONIC AN USM 207A GENERATOR SIGNAL SG 1122 U GENERATOR SIGNAL SG 1125 U OSCILLOSCOPE AN USM 281C VOLTMETER AN GSM 64
344. NOT ASSIGNED WASHER LK EXT T NO 10 195 IN ID 406 WASHER LK INTL T NO 12 218 IN ID 383 SCREW MACH 10 32 PAN HD POZI REC SST HEAT SINK NUT DISPLAY NUM DOT MAT DISPLAY NUM DOT MAT DISPLAY NUM DOT MAT DISPLAY NUM DOT MAT DISPLAY NUM DOT MAT CHAR 29 IN HIGH CHAR 29 IN HIGH CHAR 29 IN HIGH CHAR 29 IN HIGH CHAR 29 IN HIGH PR DISPLAY NUM DOT 1 CHAR 29 IN HIGH RF SCALER ASSY SAME AS 08640 60168 WITHOUT U2 AND U5 CAPACITOR FXD 2 20 10 20VDC CAPACITOR FXD 2 20 10 20VDC CAPACITOR FXD 01UF 20 100WVDC CER CAPACITOR FXD 01UF 20 100WVDC CER NOT ASSIGNED CAPACITOR FXD 01UF 20 100WVDC CER CAPACITOR FXD 100 20 200WVDC CER CAPACITOR FXD 2 2PF 25 200WVDC CER DIODE SWITCHING 2NS 80V 200MA DIODE SWITCHING 2NS 80V 200MA DIODE SWITCHING 2NS 80V 200MA DIODE SWITCHING 2NS 80V 200MA DIODE SWITCHING 2NS 80V 200MA CONNECTOR RF SMC M PC CONNECTOR RF SMC M PC RELAY REED 1A 25A 120V CONT 4 5V COIL RELAY REED 1A 25A 120V CONT 4 5V COIL HEAT SINK NUT TERMINAL STUD 40 TERMINAL STUD 040 RIVET SEMITUBULAR 0 89 BODY DIA REPLACEABLE PARTS MFR MFR PART NUMBER CODE 28480 2200 0140 28480 08640 00058 28480 2200 0105 28480 0520 0127 78189 1902 00 28480 0516 0005 28480 2200 0103 28480 2200 0155 00000 OBD 28480 2200 0504 78189 1810 00 78189 1912 03 28480 2680 0128 28480 08640 20088 28480 1990 0330 28480 1990 0330 28480 1990 0330 28480 1990 0330
345. O 8251 F 24546 C4 1 8 TO 5111 F 24546 C4 1 8 TO 10R0 F 245465 C4 1 8 TO 511R F 28480 0360 1514 28480 0360 1514 28480 0360 1514 28480 0360 1514 28480 1826 0013 07263 711HC 01295 SN7405N 28480 1902 0049 04713 SZ 10939 206 28480 08640 60115 28480 0160 2049 28480 0160 2049 28480 0160 2049 28480 0160 2049 28480 0160 2357 28480 0160 2357 01121 SMFB A2 01121 SMFB A2 01121 SMFB A2 01121 SMFB A2 24226 15 560 24226 15 560 24226 15 560 24226 15 560 24226 15 560 26365 974 307 78189 1914 00 86928 5624 16 10 28480 8160 0219 28480 8160 0220 28480 08640 00001 28480 08640 00009 28480 08640 00051 28480 08640 00052 28480 08640 20280 28480 08640 20281 28480 08640 20063 28480 08640 20089 28480 08640 20092 28480 08640 20202 28480 08640 20203 28480 08640 40003 28480 08640 40041 28480 5040 0391 28480 5040 0392 28480 5040 0393 28480 5040 0394 28480 5040 0395 28480 2190 0368 28480 2190 0019 28480 2200 0147 28480 2200 0107 28480 2200 0151 78189 1804 01 73734 9000 MODEL 8640 OPTREPLACEABLE PARTS TABLE 6 3 REPLACEABLE PARTS DESCRIPTION SCREW MACH 4 40 100 DEG FL HD POZI REC INSULATOR COUNTER SCREW MACH 4 40 PAN HD POSI REC SST 300 SCREW MACH 2 56 PAN HD POZI REC SST 300 WASHER LLK INTL T NC 2 089 IN ID 185 SCREW MACH 0 80 PAH HD SLT REC SST 300 SCREW MACH 4 40 PAN HD POSI REC SST 300 SCREW MACH 4 40 PAN HD POZI REC SST 300 RIVET BLIND BLACK NYLON 0 125 DIA SCREW MACH 4 40 PNA
346. O 82R5 F C4 1 8 TO 133R F MF7C1 2 TO 10R0 F C4 1 8 TO 5111 F MF7C1 2 TO 10R0 F C4 1 8 TO 5111 F MF7C1 2 TO 10R0 F C3 1 8 TO 5111 G C3 1 8 TO 5111 G C4 1 8 TO 196R F C4 1 8 TO 316R F MF4C1 8 TO 12R1 F C4 1 8 TO 422R F C4 1 8 TO 422R F C4 1 8 TO 1002 F MF7C1 2 TO 10R0 F C4 1 8 TO 1002 F C4 1 8 TO 2611 F C4 1 8 TO 1471 F C4 1 8 TO 2153 F C4 1 8 TO 1002 F C4 1 8 TO 1001 F C4 1 8 TO 1001 F C4 1 8 TO 511R F 08553 6012 08553 6012 08553 6012 08553 6012 08553 6012 08640 80002 0360 1514 0360 1514 0360 1514 0360 1514 1826 0013 MC1013P MC1013P MC1013P MC1013P SN75451BP MC1010P MC1010P MC1010P 1820 0753 1820 0982 1820 0736 1820 0753 1820 1354 1820 0753 1820 0557 MC1010P MC1027P MC1010P MC1013P SZ 10939 2 8120 1823 8120 1824 8120 1825 8120 1826 8120 1828 8120 1827 8120 1829 1200 0474 1200 0474 08640 60022 252 15 30 300 252 18 30 300 MODEL 8640B OPTION 004 REFERENCE HP PART DESIGNATION NUMBER All 08640 60020 11 1 0160 3548 A11C2 0160 0336 A11C3 0180 0094 11 4 0180 0094 11 5 0180 2206 A11C6 0180 1746 11 7 0180 1746 A11CR1 1901 0040 A11CR2 1901 0040 A11CR3 1901 0040 1101 1854 0003 1200 0173 1102 1854 0003 1200 0173 1103 1854 0071 1104 1854 0003 1200 0173 1105 1854 0003 1200 0173 1106 1854 0071 11 1 A11R2 0757 0346 A11R3 0757 0438 11 4 0698 3457 11 5 0698 0085 A11R6 2100 1758 Al1RT7 0698 3151 A11R8 0757 0280 11 9 0698 3453
347. OHM 10 C SIDE ADJ Add A3A4R6 0757 0442 RESISTOR FXD 10K 1 0 125W F TUBULAR Service Sheet 5 schematic Change A3A4R1 to 20K Add A3A4R6 between PC board connector pin 5 A3A4R1 7 14 Model 8640B Option 004 Manual Changes MANUAL CHANGES CHANGE L Page 1 6 paragraph 1 63 Delete 1 25A Fuse HP 2110 0094 Add 1A Fuse HP 2110 0001 Page 6 29 Table 6 3 Change A14MPI to 7124 2310 LABEL INFO 200 VA 2A IA Page 6 4 Table 6 3 Change F1 2110 0094 to F1 2110 0001 FUSE 1A 250V Service Sheet 22 schematic Change Note 2 as follows t AND 1 AMP FOR 220 240V NOTE See paragraph 7 34 for recommended instrument modification CHANGE M Page 6 23 Table 6 3 The recommended replacement for A10A2U14 is 1820 1354 Service Sheet 11 schematic Change part number for A10A2UI4 to 1820 0736 NOTE Part number 1820 1354 is the recommended replacement for 1042014 7 15 Manual Changes 7 7 INSTRUMENT IMPROVEMENT MODIFICATIONS 7 8 Hewlett Packard has developed certain recom mended instrument modifications that can be used to improve the performance and reliability of earlier versions of the instrument In some cases replacing certain parts requires a modification to make these instruments compatible with parts now in use if the original part is no longer available These modifications are outlined in the following procedures and are keyed to instruments by serial number
348. OINT BN REM AM 4 50 100 0 4 j a ase 3 3 16 0 E S 12 256 MHz 60513 al ANE 156 25 5 78 125 10 0 64 his PRF Hz AT TPO SHOWN FOR LOCK MODE PRF Hz FOR COUNT MODE 15 LESS THAN THAT SHOWN DECIMAL POINTS 2 4 9 y TOP VIEW CC 8 7 GND ABAUD TOP VIEW GND M 10 57 ce Figure 8 64 Cc VIEW CNB l 12 9 i 5 8 11 13 17 TOP VIEW CC 16 1 8 OND unter Time Base Schematic Diagram 857 SERVICE SHEET 20 PRINCIPLES OF OPERATION General The counter has two modes of operation 1 COUNT count up The counter counts the input frequency 2 PHASE LOCK count down The counter finishes the cur rent count sequence stores the count then enters phase lock counting down from the stored count to zero in a free running mode The frequency is displayed on a six digit LED numeric display Counter Operation Count Mode A8A2 When COUNTER MODE LOCK switch S1 is out Off the count sequence is as follows When the TIME BASE line is high decade counters U24 through U19 count the input pulses When TIME BASE goes low the count is inhibited the counter outputs are transferred to the outputs of storage buffers U7 through U12 which in turn drive the numeric displays ABA4UI to U6 The storage buffer outputs are latche
349. OR FXD 10K 1 0 125W F TUBULAR A3A4R7 0757 0420 RESISTOR XJ 3 750 OHM 1 0 125W A3A4R8 0698 0084 RESISTOR FXD 2 15K 1 0 125W F TUBULAR A3AA4R9 0757 0416 RESISTOR FXD 511 OHM 196 0 125W F 401 1820 0158 LIN MISCELLANEOUS LINEAR Table 6 3 The recommended replacement for A8A2U 14 is 1820 0205 Service Sheet 5 schematic Change the parti number for A3A4 Connector Board Assembly to 08640 60040 Service Sheet 6 schematic Replace appropriate portion of schematic with attached partial schematic FREQUENCY l D 1 Figure 7 4 A3A4 Connector Board Assembly Backdating Change G 7 9 Manual Changes Model 8640B Option 004 MANUAL CHANGES CHANGE G Cent d Service Sheets 20 and 21 schematic Change part number for A8A2U14 at U14B and U14A to 1820 0661 NOTE Part number 1820 0205 is the recommended replacement for 8 2014 Service Sheet H internal view Add OFFSET adjustment A3A4R5 on the left side of A3AATP2 CHANGE H Page 6 13 Table 6 3 Delete 8 1 5 Change A8A1C7 to 0160 2204 CAPACITOR FXD 100 PF 5 300 WVDC Delete ASAICR4 and CR5 Page 6 23 Table 6 3 Change A11R2 to 0757 0472 RESISTOR FXD 200K 1 0 125W TUBULAR Table 6 3 Change A20Q4 to 1853 0038 TRANSISTOR PNP S1 PD IW FT 100 MHz Service Sheet 9A schematic Change A11R2 to 200K Service Sheet 18 component locations Replac _Figure 8 6
350. OR RESISTOR RESISTOR RESISTOR RESISTOR 1K 1 125W F TUBULAR 8 25K 1 125W F TUBULAR 287 OHM 1 125W F TUBULAR 21 5K 1 125W F TUBULAR 21 5K 1 125W F TUBULAR RESISTOR RESISTOR RESISTOR RESISTOR 51 1K 1 3 3M 5 42 2K 1 42 2K 1 125W F TUBULAR 25W CC TUBULAR 125W F TUBULAR 125W F TUBULAR RESISTOR IM 5 RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 147 261 0 5 11K VAR 10K 1 6 34 25W CC TUBULAR HM 1 125W F TUBULAR HM 1 125W F TUBULAR 1 125W F TUBULAR TRMR 200 OHM 10 C 125W F TUBULAR MFR CODE 28480 24931 24931 78189 78189 28480 80120 28480 78189 11815 28480 19701 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 72136 28480 56289 28480 28480 28480 28480 28480 28480 24226 24226 04713 28480 28480 04713 28480 28480 28480 28480 28480 REPLACEABLE PARTS MFR PART NUMBER 2360 0201 HN100 11 LW101 30 1810 00 1902 00 2190 0018 MS15795 305 2950 0035 1924 02 AAP 4 3 0403 0158 MF7C1 2 TO 1RO0 F 08640 6700 08640 67003 8120 1889 8120 1887 8120 1905 8120 1892 08640 60074 0160 3094 0160 3094 0160 3094 DM15F201J0300WV1CR 0160 2204 150D225X9020A2 1901 0040 1901 0022 1901 0040 1901 0040 1901 0040 1901 0539 15 152 15 271 2N3251 1855 0049 1855 0020 2N3251 1854 0071 1854 0071 1854 0071 1854 0071 1854 0071 C4 1 8 TO 422R F 16299 24546 24546
351. OR CATHODE 0 20V OVERLOAD 9 A26A1R19 W3 AISXAI7 DET 03 CONNECTOR 05 5 2 ASRI FREQUENCY TUNE 26 AM AGCRF WB Pt P OA10 BOARD ASSY A17 POWER A3R2 FM GAIN COMPENSATION A9R1 PEAK DEVIATION VERNIER amp AMPLIFIER ASSY SUPLY HOTHER AT9A 141 LowsENS 11 3 TRIMMER ADJ A 10A 194 A26A1 POWER 4 MID SENS A11C9 AMPLIFIER AND wa VARIABLE MODULATION HISENS A11R86 DRIVE ADJ ASSY OSCILLATOR ASSY asi AMR40 AUDIO OUTPUT LEVEL D 1951 2612 AUX 8 AIQA2 RF METERING MOTHER RFOUT 02 20 MP52 BASEIN OUT ALITP2 Assy BOARD ASSY A5R9 AMPLIFIER OFFSET ALITP3 rout s 53 EXT INT ABR23 BUFFER ADJ 11 4 oscout MANE A14 LINE ASTPI 11 5 AMOUT Ka POWER ABTP2 ouTeuT OUTPUT 11 6 GND 10 dB INPUT 1048 A10A1J3 1 1 mrur A13R3 o 5 FM BUFFER IN QD wis BUFFER OUT Al9A2R7 10nV ADJ OUTPUT LEVEL 1 dB AT FM AisA2R8 1v ADI LEVE SHAPING ASSY PLATE ATR19 vaRACTOR BIAS A26U1 AMPLIFIER ATRAL NEG SHAPE 6 2602 P 0 A1 A26W1 ABA1I2 UL XE ANE ATTP2 VARACTOR ANODE A26W2 WF A26w3 2 W12
352. OTE If pulse burst amplitude is too high for low duty cycle pulses check all components connected between A26UICRI and 26 102 G1 for dc current leakage RF Amplifier Pulse Switching and Step Attenuator Troubleshooting Component Test Conditions and Normal Indication If Indication or Circuit Control Settings Is Abnormal OUTPUT AMPLIFIER Initial conditions and set 7415 dBm at RF OUT Check A26U1 Q3 and asso A26U1 tings 16 dBm output ciated circuitry Connect power meter and sensor to RF OUT Set AGC switch A26A4S1 x 3 Vdc at TP1 to AGC off Adjust OUT A26A1Q2 G1 PUT LEVEL vernier for 10 dBm at RF OUT DETECTOR BUFFER As above 3 Vdc at TP2 DET Check QI Q2 and asso AMPLIFIER A26A1 ciated circuitry SCHMITT TRIGGER Initial conditions and 5V pulse at TP6 Check A26A2U1 U2 and A26A2 settings except set AM to MOD PUL and 4V associated circuitry PULSE and set AGC switch pulse at TP5 DET PUL A26A4S1 to AGC on RATE DETECTOR Initial conditions and set Panel meter reads normal Check A26A2U3 Q7 and A26A2 tings except set AM to gt 15 dBm associated circuitry PULSE Set pulse generator pulse Panel meter reads approx repetition rate to 15 Hz imately zero BW CONTROL Initial conditions and A26A2 settings Set RANGE to 4 8 MHz a 5V at TP8 BW Set RANGE to 1 2 MHz 12V at TP8 BW Set AM to PULSE a 19V at TP8 BW BW CONTROL Initial conditions and A26A1 settings except set AM to
353. PF 0 200WVDC CER CAPACITOR FXD 5500PF 0 200WVDC CER CAPACITOR FXD 5500PF 0 200WVDC CER CAPACITOR FXD 5500PF 0 200WVDC CER COIL FXD MOLDED RF CHOKE 56UH 10 COIL FXD MOLDED RF CHOCK 56UH 10 COIL FXD MOLDED RF CHOCK 56UH 10 COIL FXD MOLDED RF CHOKE 56UH 10 COIL FXD MOLDED RF CHOKE 56UH 10 INSULATOR BSGH FLG 115 ID WASHER LK INTL T NO 1 4 256 IN ID 478 WASHER FL MN NO 8 176 IN ID 375 IN OD RFI STRIP NI ALY 1 06 W 2 64 L RFI STRIP NI ALY 2 48 W 4 215 L SHIELD LEO TAPE COVER CENTER FILTER FRAME C SHIELD LARGE FRAME C SHIELD SMALL COVER CONTROL INPUT HEAT SINK WINDOW COUNTER SUPPORT PC BOARD CENTER SHIELD BUTTON CASTING TOP CASTING BOTTOM PIPE LIGHT PIPE LIGHT OFLOW BUTTON X10 BUTTON X100 BUTTON ON BUTTON INT BUTTON EXT WASHER FL MTLC NO 5 13 IN ID 235 IN WASHER LK MLCL NO 4 115 IN ID 226 IN MODEL 8640B OPTION 004 MFR MFR PART NUMBER CODE 24546 C4 1 8 TO 6192 F 24546 C4 1 8 TO 75R0 F 24546 C4 1 8 TO 90R9 F 2446 C4 1 8 TO 121R F SCREW MACH 4 40 SCREW MACH 4 40 SCREW MACH 4 40 WASHER LK EXT T PAN HD POZI REC PAH HD POZI REC PAN HD POZI REC NO 4 116 IN ID NUT HEX DBL CHAN 1 4 32 THD SST 300 SST 300 SST 300 285 IN 094 24546 C4 1 8 TO 162R F 24546 C4 1 8 TO 101 F 16299 C4 1 8 TO 2371 F 24546 C4 1 8 TO 1101 F 16299 C4 1 8 TO 4222 F 16299 C4 1 8 TO 4222 F 16299 C4 1 8 TO 2371 F 24546 C4 1 8 TO 751 F 24546 C4 1 8 T
354. PLIFIER amm GAIN 1 vm BUFFER OFFSET R BurrR 1820 K DET o8 2 3 6 10K 4 AB P O A17 MODULATI ON METERING POWER SUPPLY MOTHER BOARD 15 RISER MOTHER BOARD ASSY 08640 60057 ASSY 08640 60018 ASSY 08640 60001 NOTES 1 NON FUNCTIONING LINE SEE BACKDATING TABLES 7 1 7 2 SCALING ANP LIFIER eee e cae m 5 M 0158 P c i ve 1 15V F ui amp 8yF T 0 01u 1 ANP j s 1 dun RS OFFSET 7 86 59 C7670B640 650069 a a 1 MP EAST i 7500 J AC 00 R 18 bo E NUT M 20V a Le R14 Jeu uF TX RIS Bvn ue OFF SET 20V REFERE ASSEMBLIES ARE ABBREVIATED FULL DESIGHATION IN ea gh ee uS CLUDES ASSEMBLY NUMBER e g RI OF ASSEMBLY Al 1 AIRI DESIGNATIONS OF OTHER COMPONENTS ARE i EPOR ae ee ee _ DEMODULATION AMPLIFIER AM INTERCONNECTIONS COMPLETE AS SHOWN AND RF ON OFFSWITCH 88408 OPTION 004 1338 15 A28A8 Figure 8 53 AM Interconnections RF ON OFF Switch and Figure
355. PMENT PROCEDURE FUNCTION GENERATOR MODEL 8640B OPTION 004 TO 26 3 RF IN FROM TEST CABLE amp ADAPTER TEST CABLE Figure 4 21 Peak Incidental Phase Modulation Test Setup Function Generator HP 3300A Vector Voltmeter 2 s s s s HP 8405 50 Ohm 2 required 2 s s s s s s HP 11536A 50 Ohm Load 2 s s s s HP11593A Test Cable 2 required HP 11592 60001 Adapter Wwe ox db 1250 0827 This test is performed with power suppliad to the instrument while protective covers are removed Be careful when performing this test Line voltage is always present on terminals including the power input connector fuse holder power switch etc In addition when the instrument is on energy available at many points may result in personal injury or death when contacted Capacitors inside the instrument may still be charged even if the instrument has been disconnected from its line power source Performance Tests 1 Disconnect instrument from the line power source Remove bottom cover from Signal Generator Using the wrench provided in the instrument remove semi rigid coaxial cable W7 from jack A26W3 labeled RF IN FROM DIV Connect one test cable from the tee to A26W3 connect other test cable with adapter from the tee to W 7 Connect instrument to line power source Allow one hour warm up time before continuing with
356. POSITION REFERENCE DESIGNATIONS WITHIN DUTLIHED ASSEMBLIES ARE BBREVIATEO FULL GESIGHATICM IH pio AAT RISER ASSY FILTER TO DIVIDER 0800 0020 Siue citur QUE LOW BAND iU j mes pj i PARRE _ REFERENCE DESIGNATIONS a PREFIX o HIGH BAND 0 6 ee tt Le N cna TS SSN BANDS AND 1637 LOWGAND E ___ wawo B 16 32 MHZ JN 23 o 1 T 18 n 16 32 FIG WE a 0 300 033 030 on 0 5 8 MHz IN Y 26 Ymsi Ri gR 86 16 52 MHz BAND H e 25 83 0 5 8 MHz BAND 0 2 i 3 10 1 VIEW o gt BE MEE 0 5 MHz BAND MH LOW BAND 00 Joad e MH HIGH ae I dd Heu Tb inh n mem 9 1 10 Avo L ul Li 1 iB 115 816 Mu B5 86 Miz IN al 2 94 10 94 560 0 00 gt pu m CH kes 409 ken Ja e J Ta T6 Ja 7 oa uoa SAM HIGH E WT MEN 120 12 9922 122 32 4 0 5 1 MHz BAND E B 32 64 MHz v 7 12 LOGIC LEVELS ON THIS SCHEMATIC QML 3 BELONG TO AND EECL FAMILIES B7 32 64 BAND 0 22 GROUND 1 HIGH AND OPEN NEG SS ATIVE 15 LOW EXCEPTIONS ARE y ELE2 MHz BAN
357. PULSE IN NE 2 own D t l 12 Q 21 RE OFF tL 15 m LO BAND 2 4 m A 1 LO BAND 1 D NEN i CRI PULSE CODE i NENNEN LL IL m e A AF AMPLIFIER PULSE PITCHING AND STEP attenua TRAS HAOR OPTION 04 1 HZA Figure 8 48 P O A26A2 AM Offset and Pulse Switching Assembly Component Locations 18 PHO OUTPUT LEVEL 1 dB ASSY 08640 60062 1418 STEP ATTENUATOR ASSY 08640 60063 1 3 EE 2 3 6 a he lt oft o 6 1 3 mj 2 3 31 1227 5 service AIS OUTPUT LEVEL 10 dB ASSY 108640 60060 MANT d 10 M 0 noone rJ 19 1 10 STEP ATTENUATOR ASSY 08640 60061 1 a LL v 1 FULL CWI 2222222 a oe j n M 41 F Wil 1 1 E 048 IH MB ils i 1 1 ca Olt h 2 0 Lo lt REFERENCE DESIGNATIONS X WE CRI 20 rap be LL I 30 0 20420 20 30 EN Z I 20930520 EIS PIO XAZ6A2_ 70 1 0 DELETED A2 AIR22 A26A2CR6 pi 2 AZ6ADKI 20 60 10 NOTES 1 NON FUNCTIONING 1 INE 4 SEE BACKDATING TABEES 7 1 AND 7 2 20 60
358. R RESISTOR RESISTOR RESISTOR RESISTOR 56 2 OHM 56 2 OHM 600 OHM 1 600 OHM 1 10K 1 1 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 25W F TUBULAR RESISTOR 10K 1 125W F TUBULAR THERMISTOR SLDR SLDR SLDR SLDR SLDR STUD STUD STUD STUD STUD TERMINAL TERMINAL TERMINAL TERMINAL TERMINAL TERMINAL SLDR STUD DIODE ZNR DIODE ZNR 3 83V 5 3 83V 5 DO 7 D0 7 PD 4W TC PD 4W TC FREQUENCY SELECT SWITCH ASSY HOUSING GEAR SPUR GEAR SPUR SHAFT AUDIO OSCILLATOR SCREW SET 4 40 SMALL CUP PT HEX REC ALY GEAR SPROCKET AUDIO SCREW SET 4 40 SMALL CUP PT HEX REC ALY RESISTOR RESISTOR RESISTOR RESISTOR RESISTOR 7 15K 1 21 5K 1 215K 1 2 4M 1 7 15K 1 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 5W F TUBULAR 125W F TUBULAR MFR CODE 24546 24546 24546 24546 24546 24546 24546 24546 24546 16299 24546 24546 24546 24546 24546 24546 24546 24546 24546 24546 16299 24546 16299 24546 24546 24546 16299 16299 19701 19701 24546 24546 16299 19701 16299 24546 24546 24546 24546 24546 24546 16299 03888 03888 24546 24546 24546 24546 24546 24546 28480 28480 28480 28480 28480 28480 28480 04713 04713 28480 28480 28480 28480 28480 28480 28480 24546 24546 16299 19701 24546 REPLACEABLE PARTS MFR PART NUMBER C4 1 8 TO 2003 F C4 1 8 TO 101 F C4 1 8 TO 101 F C4 1 8 TO 8251
359. R 10 OHM 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 315K 1 125W F TUBULAR RESISTOR 2 61K 1 125W F TUBULAR RESISTOR VAR TRMR IKOHM 5 WW RESISTOR 2 87K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 196K 1 125W F TUBULAR RESISTOR 1K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 5 11K 1 125W F TUBULAR RESISTOR 2 6K 1 125W F TUBULAR RESISTOR 100 OHM 1 125W F TUBULAR RESISTOR 100 OHM 1 125W F TUBULAR RESISTOR 100 OHM 1 125W F TUBULAR RESISTOR 100 OHM 1 125W F TUBULAR RESISTOR 2 61K 1 5W F TUBULAR RESISTOR 2 61K 1 5M F TUBULAR RESISTOR 2 61K 1 5W F TUBULAR RESISTOR 2 61K 1 5W F TUBULAR RESISTOR 600 OMM 1 125W F TUBULAR RESISTOR 600 OHN 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR RESISTOR 10K 1 125W F TUBULAR TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL SLDR STUD TERMINAL STDR STUD IC LIN AMPLIFIER DIODE ZNR 6 19V 5 DO 7 PD 4W DIODE ZNR 6 19V 5 DO 7 PD 4W FREQUENCY SELECT SWITCH ASSY HOUSING GEAR SPROCKET AUDIO RESISTOR 157K 1 125W F TUBULAR RESISTOR 392K 1 125W F TUBULAR RESISTOR 157K 1 125W F TUBULAR RESISTOR 392K 1 125W F TUBULAR SWITCH ROTARY MFR CODE 28480 28480 28480 56289 56289 56289 56289 56289 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 24546 24546 19701 16299
360. R 26742 91 6915 0702 00 MODEL 8640B OPTION 004 REFERENCE DESIGNATION A13XA5 13 7 A13XA8A3 A14 A14J1 14 1 A14P1 A15 15 1 15 2 A15MP3 A15XA17 A16 16 16 17 17 12 17 18 17 20 17 22 17 24 17 26 5 18 18 1 A18C2 A18C3 A18C4 A18C5 A18CR1 A18CR2 A18CR3 A18CR4 A18CR5 A18CR6 A18CR7 A18CR8 A18CR9 A18CR10 18 11 A18CR12 A18DS1 A18F1 18 1 A1801 A1802 A1803 1804 1805 1806 1807 QTY 1251 2571 1251 2571 5060 0109 5060 9409 1 7120 4264 1 5020 8122 1 08640 600181 0403 0153 2 0403 0154 1 0403 0155 1 1251 3308 1 08640 601191 3140 0490 1 1251 0198 5040 0327 2 08640 600011 1251 2034 3 1251 2571 1251 2571 1251 2571 1251 2034 1251 2034 08640 600041 0180 0229 5 0160 3534 4 0180 2214 0180 0197 0160 2055 1901 0040 1901 0025 1901 0025 1901 0040 1901 0040 1901 0159 5 1901 0040 1901 0040 1901 0049 2 1901 0049 1901 0040 1901 0050 1990 0326 5 2110 0425 1 4040 0752 2 1480 0073 1853 0020 1854 0232 4 1200 0173 1884 0012 5 1854 0003 1853 0027 4 1200 0173 1853 0050 4 1853 0027 1200 0173 TABLE 6 3 REPLACEABLE PARTS DESCRIPTION CONNECTOR PC EDGE 15 CONT DIP SOLDER CONNECTOR PC EDGE 15 CONT DIP SOLDER CONNECTOR 15 CONT LINE MODULE WITH FILTER JADE GRAY NSR P O
361. R RISER ASSY 19 2 RE VERNIER ASSY j BOARD ASSY 08640 60067 08640 60068 08640 60054 Ro 42 OUT t M 9 mu R1 70 ng METER ATEN SW imm OUTPUT E al Lc Q LEVEL 3160 2370 9 UP NENNEN M 00000075 9 16 sum MET we 3 70 y 6 ui 3 1 6 3 9 6 LLY vern i i 9 6 9 9 A N 74 j o 0 9 6 12 57 EJ 13 EN o 7 3 EE g 9 PIO AD 71 ER 2 MODULATION P O Al 9 9 METERING POWER SUPPLY MOTHER 15 MOTHER 9 BOARD ASSY RISER ASSY BOARD ASSY 00 0 08640 60057 08640 60018 08640 60001 9 1 HO o 3 METER ATTEN 9 7 MET OUT L 120 1 9 BENI P 9 7 26 5 R Ca Fo 2130 k Q lt 1 lt X 17 x lt H uY 94 j I 1000 95 1 TO METER At 0 95 96 iat 14 ot Pd e Lo i 14 R98 Hy ty D 2000 dcc 3 TOK 6K 1 6 6 ODD RANGE 0 CODE IL TO 0 METER CIRCUITS WERNIEN SAGE 004 4 gt ee ee X3 Edu 0D i gt Service al Fat n eb ivl RMD 6062 m ST LEVEL dBm QUTPUT L
362. RATOR S CHECKS Initial Control Settings a Push LINE switch to ON Set TIME BASE INT EXT switch on rear panel to INT b Set the controls as follows Meter Function LEVEL COUNTER MODE EXPAND Off Out LOCK Offf Out Source 20 s s s INT In TIME BASE VERNIER uoce d s due c o deco due cem AM ae gb SY ogy V Wb AP oe d ee SORE AUDIO OUTPUT LEVEL ey he te ue hu ue 5e Mele PEW MODULATION a do dba Me amp de dou MODULATION FREQUENCY 2 s 5 5 400Hz FM pecu ME np db 16 ORE PEAK DEVIATION hecho spo dy ee sat QSDIEHZ PEAK DEVIATION Vernier oue DD a RANGE 0 5 1MHz FREQUENCY TUNE Centered Four turns from stop FINE TUNE Centered 2 5 turns from stop RF ON OFF Be eo x amp ub tees Ix ue out ias cs OUTPUT LEVEL10dB 10 dBm OUTPUTLEVEL1dB OUTPUT LEVEL Vernier CAL Figure 3 5 Operator s Checks 1 of 5 Model 8640B Option 004 Operation OPERATOR S CHECKS Counter and RF Oscillator c Use a type N to BNC adapter and a BNC to BNC cable to connect RF OUT COUNTER INPUT D Adjust FREQUENCY TUNE and FINE TUNE until FREQUENCY reads 0 75000 MHz Set COUNTER MODE EXPAND to X10 FREQUENCY shoul
363. Remove A20 assy Measure re LATOR sistance from 17XA20 15 chassis ground Open pins 13 and 18 on ex Lender board Extend A20 assy and check voltage rom A20 board pin 13 to 20 4 t44 6 Replace faulty component Check supply load circuits for short Check A20U2 and supply load circuits Check diodes and transistors for correct operation with sistance voltage applied Check com ponents for correct resistance 2 CRIT 4 19 LM E s Mov d 2 um i NE 5 SP aa 1 d 7 ORIGS Correct operation and re Replace faulty component Figure 8 71 A12 Rectifier Assembly Component Locations 8 62 Model 8640B Option 004 Service AY PWR Al PWR SUP 24 SERIES SUP MOTHER MOTHER BOARD 20 5 2V AND 44 6 REGULATOR ASSEMBLY 08540 60005 REGULATOR eee LN BD ASSY 55 Iu ee ee PWR SUPPLY SOCKET ASSY 7 LINE 51 08640 80001 12 RECTIFIER ASSY 08640 60190 T P O 20 CURRENT SOURCE Im 34 REGULATOR mmm cac UM ACROWBAR m 08640 60007 REFERENCE DESIGNATIONS PETI al ome T NO PREFIX 2 ate e 3 cr 1 8 p QNIOQ ONIOO SE L cl 9 C8 Wt AM LINE POWER CL 1826 0177 VOLTAG
364. Resolution Error Accuracy 1 count INT or EXT Internal Reference Error lt 2 ppm when calibrated at 25 C every 3 months and oper ated between 15 C and 35 Fine Tuning Unlocked gt 1000 ppm total range Locked gt 20 ppm by varying internal time base vernier Stability Time after 2 hour 10 ppm 10 min lt 0 05 ppm h warmup 2 ppm total o variation Temperature 50 C 15 35 Line Voltage 5 to 10 1 lt 1 ppm voltage change Load with any passive lt 1 ppm load change lt 1 ppm None lt 1 of selected measureable peak deviation or lt 200 Hz which ever is greater Level Change Mode Change CW to FM In the External Doubler Band the 8640B Option 004 counter displays the actual doubled output frequency and the FM meter indi cates the proper peak deviation 2 When phase locked Counter Resolution error is eliminated These specifications are given for the 8640B Option 004 internal reference When using an external reference drift in the locked mode will depend on the external reference characteristics Phase lock may break due to temperature change i e during warmup Simply relock at desired frequency Sr his specification is for short term transient line changes Model 8640B Option 004 General Information Table 1 1 Specifications 2 of 6 FREQUENCY CHARACTERISTICS Cont d Restabilization Time
365. S nu xM J SEE BACKDATING TABLESTEL AND 7 2 i 1 ein 9 cw i t 8O 6 F S rt Ml A4U3 4 CIRCUIT BOARD AD 9 AN veo M TOP VIEW TOP VIEW 1 Dd 14 8 i 19 95K ad 0000000 1 KEY 7 ED TENE R i ZEE a ed 10K 21 160 lt A2U2 i MEE MEME TOP VIEW TOP VIEW vod AUTORANGE o4 COMPARATOR N pm AMPL GAIN LOGIC f Re Rie 8 160x R6 PI 3 GND 1000 is B pY R12 REFERENCE DESIGNATIONS WITHIN OUTLINED L za a 3160 ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CVM E CELER A 1854 0071 COMPLETE AS SHOWN Low X ex n E XM i ANNUNCIATOR ASSEMBLY 08640 60033 ne Ar inae 52V RIS n GND 0 ow RD 00 T Qc No 1854 0019 5 2V R16 10K R14 hy O qu Mos 1540019 27 im 10K CR2 ANNUNCIATOR LAMP COMMON 47 A2 4 AG meen a A ee Figure 8 59 Meter Circuits Schematic Diagram 8 53 SERVICE SHEET 18 PRINCIPLES OF OPERATION General The A8A1 Scaler Assembly processes the RF input to the counter In INT or EXT 0 550 MHz counter modes the input frequency is divided by 64 In the EXT 0 10 MHz mode the input frequency is not divided Comparator A8A1 In
366. S Figure 5 14 FM Sensitivity Adjustment Test Setup Variable Phwe Generator 203A Digital Voltmeter HP 3480D 3484A Option 043 Frequency Counter HP 5327 Spectrum Analyzer HP 141T 8552B 8553B Adjustments 1 Connect equipment as shown ip Figure 5 14j after setting Signal Generator s controls as follows Meter Function EE 0 COUNTER MODE EXPAND a Off LOCK 2 Off Source e 2 INT AM 2 gt amp xoxo kj 222020 OFF Me OFF PEAK DEVIATION E 2 02 40 kHz PEAK DEVIATION Vernier gt es Fully CW RANGE ios 22 2 16 32 MHz FREQUENCY TUNE m 24 MHz OUTPUT LEVEL Switches 37 dBm OUTPUT LEVEL Vernier ee CAL RF ON OFF e ON 2 Set spectrum analyzer s center frequency to 24 MHz resolution bandwidth to 3 kHz frequency span scan width per division to 20 kHz and input attenuation to 0 dB Center signal on display and use reference level controls set for 10 dB division to set signal peak to top 0 dB reference graticule line on display 3 Set Signal Generator s FM switch to AC Adjust variable phase generator for a frequency counter reading of 16 63 kHz at 707 mVrms as read on DVM 5 41 Adjustments Model 8640B Option 004 ADJUSTMENTS 4 Adjust MID FM SENS adjustment A3A4R3 for at least 50 dB of carrier null NOTE The
367. SE LOCK RESTABILIZATION TIME TEST Cont d 2 Warm up equipment for two hours Then set frequency counter to read frequency directly i e not divided down Use a 1s gate time so that the last two digits span from 00 to 99 Hz Calibrate the recorder for a zero to full scale reading that corresponds to a 00 to 99 Hz reading of the frequency counter s last two digits i e 100 Hz full scale Set COUNTER MODE LOCK to ON wait one minute then record generator s output frequency for five minutes the frequency should not vary more than 7 Hz 0 1 ppm 1 digit counter ambiguity 7 Hz Set COUNTER MODE LOCK to Off tune FREQUENCY TUNE control fully ccw and back again to approximately 50 MHz Repeat step 4 frequency should not vary more than 7 Hz 7 Hz Set COUNTER MODE LOCK to Off set RANGE switch to 64 128 MHz and back again to 32 64 MHz Repeat step 4 frequency should not vary more than 7 Hz 7 Hz Set COUNTER MODE LOCK to Off set RF ON OFF switch to OFF Wait one minute and set RF ON OFF switch to ON Repeat step 4 frequency should not vary more than 7 Hz 7 Hz This step is necessary only if the instrument is wired to tum the RF Oscillator off with RF ON OFF switch 4 93 Performance Tests Model 8640B Option 004 Table 4 4 Performance Test Record 1 of 9 Hewlett Packard Company Model 8640B Option 004 Tested By Signal Generator Serial S o Date Test Description Frequency Range Test Low
368. SISTOR 28 7 OHM 1 125W TUBULAR ATR58 0698 3434 1 RESISTOR 34 8 OHM 1 125W F TUBULAR ATR59 0757 0316 3 RESISTOR 42 2 OHM 1 125W F TUBULAR ATR60 0757 0394 8 RESISTOR 51 1 OHM 125W F TUBULAR 28480 1854 0071 28480 1854 0071 07263 517843 28480 1200 0173 28480 1853 0020 28480 1854 0071 28480 1853 0038 28480 1200 0173 28480 1853 0020 28480 1853 0020 16289 C4 1 8 T0 4642 F 16299 C4 1 8 TO 4222 F 16299 C4 1 8 TO 3831 F 24546 C4 1 8 TO 2152 F 24546 C4 1 8 TO 7501 F 16299 C4 1 8 TO 1783 F 16299 C4 1 8 TO 2153 F 19701 4 1 8 0 1332 16299 C4 1 8 TO 3832 F 16299 C4 1 8 TO 4221 F 19701 MF4C1 8 T0 9091 F 32997 3006P I 202 24546 C4 1 8 TO 3161 F 19701 MF4C1 8 T0 4643 F 24546 C4 1 8 T0 5112 F 24546 C4 1 8 TO 1102 F 16299 C4 1 8 TO 4641 F 24546 5 1 4 0 3482 32997 3006 103 16299 4 1 8 0 3481 24546 C4 1 8 TO 1471 F 24546 C4 1 8 TO 1781 F 24546 C4 1 8 TO 3161 F 19701 4 1 8 0 6191 24546 C4 1 8 TO 1102 F 16299 C4 1 8 TO 1962 F 16299 C4 1 8 TO 3162 F 24546 C4 1 8 T0 6812 F 24546 C4 1 8 TO 101 F 24546 C4 1 8 TO 121R F 24546 C4 1 8 TO 82R5 F 24546 C4 1 8 TO 56R2 F 16299 C4 1 8 TO 38R3 F 03888 PME55 1 8 TO 26R1 F 19701 MF4C1 8 T0 17R8 F 03888 PME55 1 8 TO 13R3 F 24546 C4 1 8 TO 10R0 F 24546 C4 1 8 TO 101 F 24546 C4 1 8 TO 1001 F 24546 C4 1 8 T0 5621 F 32997 3006P I 202 24546 C4 1 8 TO 1002 F 16299 C4 1 8 T0 4641 F 24546 C4 1 8 TO 1102 F 24546 C4 1 8 T0 6192 F 24546 5 1 4 0 3482
369. ST CD 3030 0007 1430 0759 3030 0196 1920 02 3030 0196 1920 02 3030 0007 2510 0135 NO 1445 2190 0017 08640 20193 5133 12 S MD R 5086 7082 550 2100 0541 SMF8 A2 SMFB A2 SMFB A2 SMFB A2 SMFB A2 SMFB A2 701872 701872 08640 00011 2200 0105 3050 0105 48 90092 08640 00011 48 90092 2200 0105 3050 0105 2740 0001 1910 00 2740 0001 1910 00 2200 0121 2190 0019 2190 0019 2200 0143 MODEL 8640B OPTION 004 REFERENCE DESIGNATION 1 2 1 2 1 1 2 2 1 2 3 1 2 4 1 2 5 1 2 6 1 2 7 1 2 8 1 2 9 1 211 A3A1A2L2 1 2 1 1 201 A3A1A202 A3A1A2R1 A3A1A2R2 A3A1A2R3 A3A1A2R4 A3A1A2R5 A3A1A2R6 A3A1A2R7 A3A1A2R8 A3A1A2R9 A3A1A2R10 1 2 1 A3A1A3 1 1 2 A3A1A3C3 A3A1A3C4 A3A1A3C5 A3A1A3C6 A3A1A3C7 A3A1A3L1 A3A1A3L2 1 1 1 301 A3A1A3Q2 1 1 A3A1A3R2 A3A1A3R3 A3A1A3R4 A3A1A3R5 A3A1A3R6 A3A1A3R7 A3A1A3R8 A3A1A3R9 A3A1A3R10 A3A1A3R11 A3A1A3R12 A3A1A3T1 A3A2 A3A2CR1 A3A2CR2 A3A2CR3 A3A2R1 A3A3 4 4 1 A3A4C2 A3A4R1 A3A4R2 A3A4R3 A3A4R4 A3A4R5 HP PART NUMBER 08640 60024 0160 3456 0160 3456 0160 3878 0160 3456 0160 3456 0160 3878 0160 3456 0160 3873 0160 3876 9140 0142 9140 0142 1200 0173 1854 0247 1854 0247 0757 0422 0698 721
370. STS 4 1 INTRODUCTION 4 2 The procedures in this section test the electrical performance of the Signal Generator using the specifications of Table I 1 as the performance standards The first test Basic Functional Checks presents steps for checking the overall basic functions of the generator The performance tests that follow provide the most comprehensive check of the specifications see note A simpler operational test is included in Section under Operator s Checks 4 3 The Basic Functional Checks should be useful for incoming inspections routine maintenance and general post repair checks but is not intended to be a complete check of specifications The test requires a minimum of commonly available equip ment and is written so that a wide variety of models with equivalent specifications may be used 4 4 EQUIPMENT REQUIRED 4 5 Tabie 4 2 lists the test equipment recom mended for the Basic Functional Checks only Equipment required for the other performance tests is listed in the Recommended Test Equipment table in S ctionlIl Any equipment that satisfies the critical specifications given in the tables may be substituted for the recommended model s 4 6 TEST RECORD 4 1 A separate check off listis provided as a test record at the end of the Basic Functional Checks Results of the other performance tests may be tabulated on the Test Record at the end of the procedures The Test Record lists all of the tested
371. Sample And Hold section of the Detector Buffer Amplifier when the RF is off The Pulse Overload Detector senses any large errors in the leveling circuit which can occur when the OUTPUT LEVEL vernier is reduced In such a case the hold function is defeated until equilibrium occurs The FM Circuits and RF Oscillator Troubleshooting 4 SERVICE SHEET 2 Service Rate Detector senses pulses of low repetition rate and turns off the meter circuit when the rate is so low that the meter is no longer accurate The Modulation Overload Detector senses when the AGC reference the AM signal or a combina tion of the two is beyond the Modulator s capa bility to deliver power The REDUCE PEAK POWER lamp is then turned on The Meter Amplifier produces an output voltage proportional to the detected output voltage and hence the output level to drive the meter circuits The AGC reference voltage originates in the AM Offset Amplifier where it is summed with any AM input signal The voltage out of the amplifier then passes through the OUTPUT LEVEL vernier to the modulation Summing Amplifier The Modulator can be disabled 1 maximum modulator attenua tion by the RF ON OFF switch Meter Circuits Service Sheet 17 The meter can be set to measure either percent AM peak frequency deviation FM or output level In measuring AM and FM the modulation signal is peak detected by the Positive Peak Detec tor and amplified For output level the output
372. See Table 4 1 Recommended Test Abridgements MODEL 86408 OPTION 004 0 0 0 0 Cre ex ister t TEST OSCILLATOR 502 OUTPUT STEP 3 Figure 4 32 Counter External Sensitivity Test Setup EQUIPMENT Test Oscillator PROCEDURE HP 652A l Connect RF OUT to COUNTER INPUT as shown ih Figure 4 32 after setting Signal Generator s controls as follows Meter Function COUNTER MODE EXPAND LOCK Source TIME BASE VERNIER AM FM RANGE FREQUENCY TUNE OUTPUT LEVEL RF ON OFF LEVEL ENSE off INT CAL OFF OFF 256 512 MHz 550 MHz 100 mVOLTS ON 2 Set COUNTER MODE Source to EXT 0 550 Slowly tune Signal Generator to 0 5 MHz using RANGE and FREQUENCY TUNE The counter should indicate the frequency of the signal at RF OUT at all frequencies 0 5 to 550 MHz V 4 87 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 47 COUNTER EXTERNAL SENSITIVITY TEST Cont d 3 Disconnect RF OUT from COUNTER INPUT Connect the oscillator to COUNTER INPUT and set it for 500 kHz at 100 mVrms into 50 ohms Slowly tune oscillator to 20 Hz The counter should indicate the frequency of the signal from the test oscillator at all frequencies 20 Hz to 500 kHz J 4 Set COUNTER MODE Source to EXT 0 10 and slowly tune oscillator from 10 Hz to 10 MHz The counter should indicate the frequency of the signal from the test oscillator at all frequenci
373. TER MODE LOCK to ON and vary test oscillator frequency Pulse width al pin 6 7 25 ns low going pulse Check U1 U2 U14 U15 Each Display digit capable of being cycled up from 0 9 of being cycled down from 9 0 Each Display digit capable Check Counter and circuitry associated with faulty digit Check U1B U2 U13 U25 028 and associated circuitry Check U5 018 ABAATYS2 and associated circuitry Check Q3 5 U3 U16 SS 21 and associated circuilry STALL Initial conditions and settings Display count counts down COUNTER with test points ungrounded to 000000 decrementing A8A2 Set test oscillator frequency 1 coun per input cycle to 64 Hz then Ground TP2 Hz When count reaches Ground TP4 Set COUNTER 000000 the following will MODE LOCK to ON happen Input Display MOTE torf Cycle 028 6 Count nerease lest oscillator fre quency lo set display count to 0 Low 000000 z 000010 then reset frequency 1 Low 393999 to 64 Hz 2 Low 999999 You can also use a Logic Pulser 3 Low 999999 such as 10526 to inject 4 Low 999999 pulses into KASAS pin 16 i e 3 High 399983 the input to UISA High 399983 7 High 899989 8 High 333389 g Low 999989 10 Low 999989 11 Low 999988 12 Low 999987 NOTE 0 The count has reached 000000 11 The main counter underflows to 999999 and presets to the displayed count 999999 2
374. TIME BASE VERNIER 21 TIME B M 11 21 L LOCK tL y g BR yk 13 45 7 D 44 5 1 16 OVERFLU 1 Z LIME BASE VERNIER OVERFLOW DETECTOR i sommo O 2 om pers ES HS i ee cL I c M T IU I A Iu HE E COUNTER AnD OPTION 71 REFERENCE DESIGNATIONS C3 14 19 30 1 2 035 18 839 45 47 49 R50 55 57 1 2 5 11 2 4 25 127 28 DELETED 8 2 46 2 48 ASAAR NOTES F SEE BACKDATING TABLES 7 1 AND 7 2 DIGIT NUMBER 12 19 24 28 V TOP VIEW CC 16 8 GND ABA2UL 2 4 6 13 18 25 27 TOP VIEW 8 TOP VIEW CIRCUIT BOARD TOP VIEW oocooonon 7 ABA 2 ABA4 Figure 8 67 Up Down Counter and Display Schematic Diagram 8 59 SERVICE SHEET 21 PRINCIPLES OF OPERATION General A8A2 The lock mode is entered as follows Cross coupled NANI gates U3A and U3B form an RS flip flop The output of USA is low in the count mode and goes high after S1 is depressed and TIME BASE goes
375. TM 11 6625 2780 14 amp P TECHNICAL MANUAL OPERATOR S ORGANIZATIONAL DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS FOR SIGNAL GENERATORS SG 1 112 V 1 U NSN 6625 00 566 3067 AND SG 1112 V 2 U NSN 6625 00 500 6525 HEWLETT PACKARD MODEL 86408 OPTIONS 001 AND 004 HEADQUARTERS DEPARTMENT OF THE ARMY 31 DECEMBER 1980 By Order of the Secretary of the Army Official J C PENNINGTON Major General United States Army The Adjutant General DISTRIBUTION To be distributed in accordance with distribution list E C MEYER General United States Army Chief of Staff This manual contains copyright material reproduced by permission of the Hewlett Packard Company TM 11 6625 2780 14 amp P TECHNICAL MANUAL HEADQUARTERS DEPARTMENT OF THE ARMY No 11 6625 2780 14 amp P WASHINGTON DC 31 December 1980 OPERATOR S ORGANIZATIONAL DIRECT SUPPORT AND GENERAL SUPPORT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LISTS FOR SIGNAL GENERATORS SG 1112 V 1 U NSN 6625 00 566 3067 AND SG 1112 V 2 U NSN 6625 00 500 6525 HEWLETT PACKARD MODEL 8640B OPTIONS 001 AND 004 REPORTING ERRORS AND RECOMMENDING IMPROVEMENTS You can help improve this manual If you find any mistakes or if you know of a way to improve the procedures please let us know Mail your letter DA Form 2028 Recommended Changes to Publications and Blank Forms or DA Form 2028 2 located
376. TOR NPN TRANSISTOR NPN TRANSISTOR PNP TRANSISTOR NPN TRANSISTOR NPN TRANSISTOR PNP TRANSISTOR PNP TRANSISTOR NPN RESISTOR 196 RESISTOR 5 11K RESISTOR 5 11K RESISTOR 5 11K RESISTOR 1 33K RESISTOR 1 33K RESISTOR 2 61K RESISTOR 2 61K RESISTOR 51 1K RESISTOR 51 1K RESISTOR 820K RESISTOR 820K RESISTOR 19 6K RESISTOR 31 6K RESISTOR 51 1K RESISTOR 19 6K RESISTOR 100K RESISTOR 100K RESISTOR 51 1K RESISTOR 147K RESISTOR 5 11K RESISTOR 5 11K RESISTOR 51 1K RESISTOR 10K 2 RESISTOR 100K RESISTOR 1965 RESISTOR 10K 2 RESISTOR 10K 2 RESISTOR 6 81K RESISTOR 8 25K 6 14 LACEABLE PARTS 047PF 10 1000WVDC CER 100PF 10 1000WVDC CER 300PF 5 300WVDC MICA 100PF 20 200WVDC CER 01UF 20 100WVDC CER 01UF 20 100WVDC CER 47UF 80 20 25WVDC CER lUF 4 10 100WVDC CER 51PF 5 300WVDC MICA 1UF 10 35VDC TA SOLID 2 20 10 20VDC 010 20 100WVDC CER 2 20 10 20VDC 01UF 80 20 100WVDC CER 010 80 20 100WVDC CER 010 80 20 100WVDC CER 100 5 300WVDC MICA 47PF 20 200WVDC CER 47PF 20 200WVDC CER 47PF 20 200WVDC CER 1000PF 10 1000WVDC CER GG 2NS 30V 50MA 2NS 30V 50MA DED RF CHOKE 24UH 5 DED RF CHOKE 15UH 10 SI PD 300MW FT 200MHZ SI CHIP PD 300MW SI CHIP PD 300MW SI PD 300MW FT 200MHZ SI PD 300MW FT 200MHZ GET N CHAN D MODE SI SI CHIP PD 300MW SI PD 300MW FT 200MHZ SI PD 300MW FT 200MHZ SI PD 300MW FT 200MHZ SI PD 300MW
377. U1 is internally connected as a voltage follower The output of U1 drives the meter attenuator Service Sheet 8 the over deviation detector Service Sheet 8 and the FM Gain Compensation circuit through relay K1 When the FM switch is OFF or if the PEAK DEVIATION switch is set to an unallowable position the relay is de energized and the signal path to the FM and meter circuits is opened FM gain compensation potentiometer A3R2 is geared to the FREQUENCY TUNE control and adjusts the gain of the circuit FM sensitivity is higher for higher RF oscillator frequencies and the FM Gain Compensation circuit reduces the modulation circuit drive at high frequencies The gain compensation adjustment potentiometers A3A4R2 R3 and R4 set the FM sensitivity at the frequency mid point and extremes The output of the FM Gain Compensation circuit drives the FM Amplifier input Amplifier A5 The FM Amplifier is a non linear feedback amplifier which drives the varactor diodes in the RF oscillator The amplifier and shaping circuits correct for the non linear tuning sensitivity of the RF oscillator by the varactor diodes The correction for the negative excursions of the modulation signal is provided by the negative shaping circuit Service Sheet 7 which follows the amplifier output Correction for positive excursions is provided by the positive shaping circuit Service Sheet 7 which is part of the amplifier feedback path Transistors Q1 through Q4 form a tw
378. U2 12 high pins 3 and 6 2 U3Bpin 4 low 3 U3A pin 2 high 4 TP4 FM OVER LOAD low Adjust PEAK REDUCE FM Replace faulty com DEVIATION VERNIER lamp ponent vernier for 2 4 lit and V p pat U2 1 pins 6 8 10 pins 3 and 6 12 low 2 U3B pin 4 high 3 U3A pin 2 low 4 TP4 FM OVER LOAD gt 2 Vp P SCALE Initial conditions SCALE lamps light Check scale lamps ANNUNCI and settings Set as follows A6 and switches ATOR Meter Function to A9 LAMP FM and set CONTROL PEAK DEVIA A9 TION as follows 5 kHz 10 kHz 20 kHz 40 kHz 80 kHz 160 kHz 320 kHz 640 kHz 1 28 MHz 2 56 MHz 5 12 MHz Figure 8 30 P O A6 Annunciator Assembly Component Locations FM Shaping Circuits and Phase Lock Loop Filter A7 A9 SERVICE SHEET 7 Service Model 8640B Option 004 8 32 A9 TOP VIEW Figure 8 31 P O A9 Peak Deviation and Range Switch Assembly Component Locations 1 of 2 Model 8640B Option 004 Service OMMON METER DRIVE 709 926 ASST uM METER ATTENUATOR 10 n u C912 ES Nos 7 OVER DEVIATION DETECTOR AND METER CONTROL CIRCUITS 86408 OPTION 004 13234 P O AI3 MODULATION METERING P O A6 ANNUNCIATOR MOTHER BOARD ASSEMBLY 08640 60057 AI FM SHAPING ASSEMBLY 08640 60046 Tes __ _ 2 ASSEMBLY 08640 60033 _ REFERENCE DESIGNATIONS n Aue OVER DEVI
379. UBULAR 125W F TUBULAR m 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 200WVDC POLYE 200WVDC POLYE 200WVDC POLYE MFR CODE 28480 56289 56289 56289 56289 56289 72136 56289 28480 56289 28480 28480 56289 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 24226 24226 28480 00000 28480 00000 28480 28480 04713 28480 28480 28480 28480 28480 28480 19701 19701 24546 19701 19701 24546 24546 24546 24546 24546 24546 19701 16299 24546 16299 24566 16299 16299 24546 24546 24546 24546 19701 16299 24546 24546 24546 16299 24546 24546 REPLACEABLE PARTS MFR PART NUMBER 0160 3458 1500105 9035 2 150D225X9020A2 292P47292 292P18392 292P10392 DM15E560J0300WV1CR 1500105 9035 2 0160 2055 292 12292 0160 3534 0160 3459 292 47292 1901 0040 1901 0040 1901 0040 1901 0040 1901 0022 1901 0022 1910 0016 1910 0016 1910 0016 1901 0022 1901 0040 1901 0022 1901 0539 1901 0518 1901 0040 0490 1080 15 243 15 243 4040 0749 OBD 4040 0753 OBD 1854 0221 1854 0071 2N3251 1854 0221 1853 0034 1854 0071 1853 0034 1854 0071 1854 0071 50 502 ET50X202 4 1 8 0 101 1 8 0 6191 MF4C1 8 T0 6191 F C4 1 8 T0 7501 F C4 1 8 T0 1101 F C4 1 8 TO 7501 F C4 1 8 T0 1003 F C4 1 8 T0 1002 F C4 1 8 T0 1002 F ET50X203
380. V regulator described on Service Sheet 22 except that the 5 2V output is taken from the point corresponding to the ground point on the 5 2V regulator and the 5 2V ground return is connected to a point that corresponds to the 5 2V output In addition diodes CR2 and CR3 give the output voltage a small negative temperature coefficient Fan Motor and Fan Driver A18 Fan Motor 16 1 is a brushless dc motor comprising a cylindrical permanent magnet rotor and a four section stator winding The motor s stator windings are energized sequentially by the Fan Driver circuit Two Hall generators are located on the stator 90 apart In the presence of a magnetic field each Hall generator will produce two out of phase voltages at its two output terminals The magnitude of the voltage is proportional to the strength of the field and the amount of bias current The phase is determined by the polarity of the field The Hall generators sense the position of the rotor and turn on the appropriate drive transistors Fan Speed Regulator 8 An emf which is proportional to rotor speed is generated in the unenergized stator windings Diodes CR4 and detect this emf and charge C4 to a negative voltage Current source discharges C4 at a constant rate The voltage across C4 plus the constant voltage drop across RI 5 is the base voltage of Q4 If rotor speed decreases the voltage across C4 becomes less negative the base of
381. VAR 2 5KOHM CABLE ASSEMBLY COAX PEAK DEVIATION BAND SWITCHBOARD ASSEMBLY DOES NOT INCLUDE ROTORS A9A1MP31 and A9AIMP30 51 AND S2 RESISTOR FXD 4 259K OHM RESISTOR FXD 1 071K OHM RESISTOR FXD 1 284K OHM RESISTOR FXD 75 OHM 1 RESISTOR FXD 1 493K OHM RESISTOR FXD 82 5 OHM 1 RESISTOR FXD 1 556K OHM RESISTOR FXD 90 9 OHM 1 RESISTOR FXD 90 9 OHM 1 NSR INCLUDES PRINTED CIRCUIT TRACES AND ROTOR A9A1MP31 NSR INCLUDES PRINTED CIRCUIT TRACES AND ROTOR A9A1MP30 CHANGE 7 Cont d A9A1A2 9 1 2 1 9 1 2 2 A9A1A2C3 A9A1A2C4 A9A1A2C5 A9A1A2C6 A9A1A2C7 9 1 2 8 A9A1A2CO A9ATA2RI 9 1 2 2 9 1 2 9 2 4 9 1 2 5 9 1 2 6 9 1 2 7 9 1 2 8 9 1 2 9 AQAIA2R10 A9ATA2RII A9A1A2RI2 A9ATA2RI3 A9ATA2RIA 9 1 2 15 A9A1A2RI6 A9A1A2RI7 A9A1A2RI8 9 1 2 19 9 1 2 20 A9A1IA2SI 9 2 A9A2PI Model 8640B Option 004 08640 60254 0140 0191 0140 0191 0140 0191 0140 0191 0140 0191 0160 2204 0160 3537 0160 2222 0160 2204 0757 0280 0757 0278 0757 0274 0757 0416 0698 0082 0757 0280 06907799 0698 5669 0698 8212 0698 5669 0698 8213 06905669 0698 8213 0757 0280 0698 5669 0698 8213 0698 5669 0698 8213 0698 5669 0757 0447 0864060256 1251 1959 08640 00101 08640 20256 08640 90073 FM GAIN SWTCH BOARD ASSEMBLY DOES NOT INCLUDE ROTOR A9AIMP29 P O SI CAPACITOR FXD 56 PF 300V CAPACITOR FXD 5
382. VEL switches to 16 dBm Set MODULATION full CW Initial conditions and set tings except set AM to OFF CAUTION Check that OUTPUT LEVEL switch is set one step ccw from full cw Short TP5 GND to 0 Vdc at OVLD TP4 VERN REDUCE PEAK POWER annunciator unlit REDUCE PEAK POWER annunciator lit 49V at OVLD Check U2 Q8 Q9 and associated circuitry Check U1B and associate circuitry Model 8640B Option 004 cervice A26 AMAGC AND RF AMPLIFIER ASSY MOCO L l ae a Je o e ee m LLL AGC AMPLIFIER ASSY 08640 60165 O2 LL OLL i ee Mod yw 816 4821 826 MA CRI sio 510 5110 Ral C AUX RE OUT 7 EE 15 eo 19 BAND iU 8 100K 15 uu met 1 juo ED RE OUT ee L 10 Tonus 14 PULSE CODE 11 I i 5 d 15 Oxus LO BAND 2 L 1 Du AIT TURN le N 15 0 4 C O0 PULSED LO uF SEE NOTE 1 WO lt 1 i cre SUMMING AMPLIFIER 0v ov rmv B H RG R15 R22 REFERENCE DESIGNATIONS WITHIN OUTLINED LOuF 5 1 7K ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN t 3 CLUDES ASSEWBLY NUMBER og Rl ASSEMBLY Al CRIN AIR DESIGHATIONS OF OTHER COMPONENTS ARE LOS Tt GND a COMPLETE AS SHOWN e 0 01 HF
383. W F TUBULAR 125W F TUBULAR F TUBULAR UBULAR UBULAR TUBULAR 4W TC 06 D 4W 1W MAX PD D 4W PD 4W TC MFR CODE 56289 56289 56289 56289 56289 56289 56289 28480 04713 28480 04713 28480 28480 28480 28480 71400 71400 28480 00000 28480 00000 02735 28480 28480 07263 28480 02735 28480 28480 28480 02735 16299 16299 24546 16299 19701 16299 16299 32997 24546 91637 19701 24546 16299 75042 24546 32997 16299 24546 16299 24546 91637 24546 24546 16299 75042 75042 24546 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 15818 15818 04713 04713 04713 04713 04713 REPLACEABLE PARTS MFR PART NUMBER 292P10292 150D336X9010B2 109D336X0075F2 150D226X9015B2 292P27292 1500227 901052 150D336X9010B2 0160 3094 SR1358 4 1901 0050 SR1358 4 1901 0050 1901 0050 1990 0326 1990 0326 GMW 3 TYPE GMW 1 2 4040 0748 OBD 4040 0753 OBD 2N3528 1854 0232 1200 0173 517843 1200 0173 235415 1200 0173 1853 0020 1854 0023 283528 C4 1 8 TO 3162 F C4 1 8 TO 147R F C4 1 8 TO 7502 F C4 1 8 TO 1961 F MF7C1 2 TO 1961 F C4 1 8 TO 4641 F C4 1 8 TO 2872 F 3006P I 102 C4 1 8 TO 5111 F RS1 2 T2 IRO J MF7C1 2 TO 619R F C4 1 8 TO 68R1 F C4 1 8 TO 422R F BWH2 1R0 J C4 1 8 TO 751 F 3006P 1 501 C4 1 8 TO 2371 F C4 1 8 TO 511R F C4 1 8 TO 196R F C4 1 8 TO 751 F RS1 2 T2 1R0 J C4 1 8 TO 42R2 F C4 1 8 TO 68R1
384. W signal at 13 dBm output vernier maximum cw Set 40 dB amplifier s input impedance switch to 50 ohms 4 28 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 22 SINGLE SIDEBAND BROADBAND NOISE FLOOR TEST Cont d 3 Set spectrum analyzer s resolution bandwidth to 1 kHz set input level control to 40 dBm and dBm dBV to dBm 50 ohm and adjust frequency controls to set the 5 kHz difference frequency in the center of the display Set analyzer s display reference level controls for 10 dB per division with the 5 kHz difference signal 1 3 dB from the top reference graticule line on the display NOTE The correction factors for this measurement are as follows a The DSB to SSB transfer is 3 dB because the mixing process translates two uncorrelated 1 kHz BW portions of the noise into the 1 kHz BW of the analyzer giving 2 times the effective noise voltage b 2 5 dB because noise is average detected after logging c 0 8 dB Effective noise BW is 1 2 x 3 dB BW which gives 0 8 dB 10 log actual 3 dB BW nominal 3 dB B Summing the correction factors gives 1 3 dB 10 log actual 3 dB BW nominal 3 dB BW or approximately 1 3 dB 1 dB 4 Change reference signal generator s output frequency to 501 00 MHz Set 10 dB step attenuator to O dB Set analyzer s display smoothing video filter to 10 Hz The top graticule line on analyzer s display represents 110 dB the transfer from a 1 KHz BW to a 1
385. X 50 OHM CABLE COAX 50 OHN CABLE COAX 50 OHM SOCKET ELEC IC SOCKET ELEC IC RISER ASSY CONNECTOR PC EDG CONNECTOR PC EDG 6 23 1 125 F TUBULAR 1 125W F TUBULAR 125W F TUBULAR 5W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 125W F TUBULAR 25W F TUBULAR 25W F TUBULAR 1 125W F TUBULAR CODE BLUE CODE BLUE CODE BLUE CODE BLUE 2 TURN UD UD UD UD FLIP FLOP FLIP FLOP FLIP FLOP FLIP FLOP P DRIVER GATE GATE GATE GATE FLIP FLOP GATE FLIP FLOP DO 7 PD 4W TC 086 0D 086 086 086 086 0D 086 0D 086 0D 14 CONT DIP SLDR TERM 14 CONT DIP SLDR TERM E 15 CONT DIP SOLDER E 18 CONT DIP SOLDER MFR CODE 19701 24546 24546 24546 24546 24546 24546 24546 16299 19701 24546 19701 24546 19701 24546 24546 16299 16299 19701 16299 16299 24546 19701 24546 16299 24546 16299 24546 24546 24546 24546 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 04713 04713 04713 04713 01295 04713 04713 04713 28480 28480 28480 28480 28480 28480 28480 04713 04713 04713 04713 04713 28480 28480 28480 28480 28480 28480 28480 28480 28480 28480 71785 71785 REPLACEABLE PARTS MFR PART NUMBER MF7C1 2 TO 10R0 F C4 1 8 TO 5111 F C3 1 8 TO 316R G C3 1 8 TO 196R G C3 1 8 TO 12R1 G C3 1 8 TO 422R G C3 1 8 TO 422R G C4 1 8 T
386. XD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD APACITOR FXD 4 CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR FXD CAPACITOR VAR CAPACITOR VAR CAPACITOR VAR CAPACITOR VAR CAPACITOR FXD LACEABLE PARTS 320PF 300WVDC MICA 200PF 1 300WVDC MICA 130PF 5 300MVDC MICA 200PF 1 300MVDC MICA 200PF 1 300WVDC MICA 130PF 5 300WVDC MICA 750PF 1 300WVDC MICA 3200PF 4 1 100WVDC MICA 4000PF 1 100WVDC MICA 3900PF 1 500WVDC MICA 2780PF 4 2 300WVDC MICA 3000PF 1 100WVDC MICA 2000PF 1 100WVDC MICA 360PF 1 300WVDC MICA 640PF 1 300WVDC MICA 640PF 4 1 300WVDC MICA 390PF 5 300MVDC MICA 240PF 5 300WVDC MICA 430PF 5 3002WVDC MICA 430PF 5 300WVDC MICA 240PF 5 300WVDC MICA 360PF 1 300WVDC MICA 1600PF 1 100WVDC MICA 2000PF 1 100WVDC MICA 1916PF 4 1 100WVDC MICA 1400PF 4 1 100WVDC MICA 1470PF 4 1 100WVDC MICA 1000PF 401 500WVDC MICA 91PF 1 300WVDC MICA 160PF 5 300WDC MICA 100 300WVDC MICA 100 5 300WVDC MICA 62PF 5 300WVDC MICA 110 1 300WVDC MICA 110 1 300WVDC MICA 62PF 5 300WVDC MICA 180PF 2 300WVDC MICA 800PF 1 300WVDC MICA 1000PF 1 500WVDC MICA 4 7PF 5 100WVDC CER 7
387. Y TUNE and FINE and set COUNTER MODE LOCK to ON NOTE get an accurate indication of frequency when not phase locked set TIME BASE VERNIER to CAL To use an external frequency doubler connect to RF OUT and set RANGE to 512 1024 MHz DOUBLER The FREQUENCY display will indicate the frequency out of doubler i e the FREQUENCY display indicates twice the frequency at RF OUT Amplitude a To enable the RF signal set the RF ON OFF switch to ON NOTE The RF ON OFF switch may be wired to turn off only the amplitude modulator This allows the RF Oscillator to remain warmed up the Auxiliary RF Output to remain on and the counter and phase lock to remain operating If it is desirable to switch both the modulator and the oscillator off the RF ON OFF function may be easily modified see Service Sheet 5 in Section VIII The Model 8640B Option 004 indicates RF output amplitude in units of power dBm 502 or voltage V mV uV With the vernier in the CAL detent position RF Output in dBm is determined by summing the values indicated on the two OUTPUT LEVEL dials When the vernier is not in CAL detent an approximate value of output power is derived by the summing method mentioned above The actual value is then read on the front panel meter o dBm scale When RF amplitude is read in units of voltage the OUTPUT LEVEL 10 dB dial indicates meter range if the small OUTPUT LEVEL 1 dB dial is be
388. a 4 qu d 4 In the EXPAND X10 mode EXP 10 is low the output of UID is high the set S input of flip flop U2A is low and sets the output e Q is low The D input of U2B is low Except at the termination of the time base period the clear CLR input of U2A and the set S input of U2B are high The Q output of U2B is high and holds the output of OR gate high At the termination of a time base period the set input of U2B goes momentarily low the Q output goes low until the clock pulse returns it to a high The output of OR gate is low for one low clock period then it goes high The T input of U3 then receives one trigger pulse for each time base period in EXPAND X10 At the termination of a time base period the shift register is cleared the input data is transferred to the output and then shifted up one bit A high appears in the output Q4 of U3 when shifting because the serial SER input is a high i e open Counter RF Scaler A8A1 SERVICE SHEET 18 SERVICE SHEET 19 Cont d In the EXPAND X100 mode EXP 100 is low the output of UID is high Except at the termination of a time base period the clear and set inputs of U2A and U2B are high Q output of UZA is low and the Q output of U2B is high therefore ihe output of OR gate is high At the termination of a time base period the set input of U2B goes momentarily low as does the clear input of U2A which causes th
389. able length of air line This reflected signal is re reflected by any mismatch at the jack The re reflected signal combines with the output signal according to the relative phase and magnitude of the two signals The combined signal is monitored by a directional coupler and then measured by a voltmeter Maximum and minimum power levels are noted as the electrical length of the stub is varied 1 the distance from the RF OUT jack to the coaxial short is varied VSWR is then calculated from the distance from the RF OUT jack to the coaxial short is varied VSWR is then calculated from the formula VSWR V Vi See 4 1 Recommended Test Abridgements CA NT DIRECTIONAL COUPLER n REFERENCE 500 TERMINATION Figure 4 13 Output Impedance Test Setup Signal Frequency EQUIPMENT Directional Coupler HP 778D Option 12 Adapter N Male to GR 874 HP 1250 0847 Adjustable Stub General Radio 874 D50L Vector Voltmeter Hp 8405A 509 Tee a uo a s cu a a dox XO A d Hpl1536A 500 Termination HP 908A PROCEDURE 1 Connect equipment as shown ip Figure 4 13 after setting Signal Generator s controls as follows 4 47 Performance Tests PERFORMANCE TESTS 4 28 OUTPUT IMPEDANCE TEST Signal Frequency Cont d Model 8640B Option 004 Meter Function LEVEL COUNTER MODE EXPAND Off LOC
390. able parts list given in Section VI 8 39 BASIC CIRCUIT THEORY 8 40 Binary Circuits and Symbols 8 41 Introduction The binary circuits and symbols used in this manual are as shown in Figure 8 3 This instrument uses three different families of logic circuits TTL ECL and EECL Most of the logic devices used in this instrument are TTL there are notes on the Service Sheets that in dicate what families the non TTL devices belong to indicates the voltage levels that are associated with each family The table also shows the effect that an open and a ground has on each family 8 42 In general binary signals that are active low are indicated with an L in parenthesis e g CLOCK L indicates a clock signal that is active low Active high signals are indicated with an H in parenthesis A circle at an input indicates that it is active low or triggers on a low going edge a circle at an output indicates inversion or that the output is active low Active high inputs inputs which trigger on a high going edge and active high ouputs are shown without the circle Complementary outputs are usually designated with a not bar e g the complement of J K flip flop s Q output is its Q output Both and may be simultaneously high in some instances e g when both SET and CLEAR are low on some D flip flops 8 5 Service NOTE The term binary coded decimal or BCD refers to four bit binary circuits that range from decimal O t
391. acy Total Counter Reference Count Resolution Error Accuracy 1 count INT or EXT Internal Reference Error lt t 2 ppm when calibrated at 25 C every 3 months and operated between 15 C and 35 C When phase locked Counter Resolution error is eliminated Fine Tuning Unlocked gt 1000 ppm total range Locked mode gt 20 ppm by varying internal time base vernier DESCRIPTION Frequency accuracy is checked using the Signal Generator s internal reference by comparing the generator s counter indication to the frequency reading on an external frequency counter The fine tune range is also checked with the external counter See le 4 1 Recommended Test Abridgements EQUIPMENT Frequency Counter HP 5327 Option H49 PROCEDURE 1 Connect generator s AU RF OUTPUT jack located on rear panel to frequency counter s input after setting Signal Generator s controls as follows Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 14 FREQUENCY ACCURACY AND FINE TUNE TEST Cont d COUNTER MODE EXPAND X100 LOCK s ns u one ds a P Source FM OFF ACN 221010101010 32 64 MHz FREQUENCY TUNE 50 MHz RF ON OFF LON 2 Allow Signal Generator and frequency counter to stabilize for two hours 3 Set frequency counter time base to give at least one more digit resolution than t
392. age 6 23 Table 6 3 Delete ALOA2R38 and R39 Service Sheet 11 schematic Delete resistors AIOA2R38 and R39 Service Sheet 19 schematic Make the following changes to the A8A3 assembly Change R1O and R17 to 1960 ohms Change part numbers for U1O U16 and 017 to 1820 1490 Change part numbers for 013 014 and 015 to 1820 1429 CHANGE 16 Table 6 3 Change A7R28 to 0757 0465 RESISTOR FXD 1 J 0 125 W TC Ox100 Change A7R45 to 0698 3159 RESISTOR FXD 26 1K 19 0 125W TC 0 100 NOTE For instruments with serial prefixes below 1552A the recommended replacement for A7R28 is 0757 0465 and for A7R45 is 0698 3159 For instruments not already modified as above it will be necessary to replace both A7R28 and A7R45 the first time either resistor is replaced Model 8640B Option 004 08640 80073 CHANGE 16 Cont d Peragraph 5 21 cent d 36 Compute the value of A5R42 using the following formula A5R42 40 2 405 fnull where 5 42 is ohms and fnull is the frequency in kHz where the null at least 60 dB occured d Choose the next lowest standard resistance value and solder it between pins 11 and 12 of the A5 FM Amplifier circuit board e Perform the FM Sensitivity Adjustment Page 5 3 Table 5 1 Make the following addition to the table Range cf Values Basis of Selection Fame imitate sae panga s23 Table 6 3 Add A5R42 RESISTOR NORMALLY NOT LOADED Table 6 3 Chang
393. al Generator s controls as follows AM INT AUDIO OUTPUT LEVEL r IW Standard 3V Option 001 MODULATION Fully CW MODULATION FREQUENCY D i 400 Hz fixed The frequency counter should read 400 8 Hz on a standard instrument 400 12 Hz on an Option 001 The voltmeter should read greater than 1 Vrms on a standard instrument 3 Vrms on an Option 001 Standard 302 408 Hz 1 0 Vrms Option 001 388 412 Hz 3 0 Vrms Set MODULATION FREQUENCY to 1 kHz fixed The frequency counter should read 1000 20 Hz on a standard instrument 1000 30 Hz on an Option 001 and the voltmeter should read as specified above Standard 980 1020 Hz 1 0 Vrms Option 001 970 1030 Hz 3 0 Vrms Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 32 INTERNAL MODULATION OSCILLATOR TEST Cont d 4 If testing an Option 001 set AUDIO OUTPUT LEVEL to and slowly tune MODULATION FREQUENCY through its variable range from 20 Hz to 600 kHz The MODULATION FREQUENCY controls should read within 10 of the frequency counter reading at all frequencies 4 33 INTERNAL MODULATION OSCILLATOR DISTORTION TEST Option 001 SPECIFICATION Total Harmonic Distortion lt 0 25 400 and 1 kHz fixed tones lt 0 5 20 HZ to 2 kHz lt 1 0 2 kHz to 600 kHz DESCRIPTION A distortion analyzer is used to measure distortion on the output of the oscillator See Table 4 1 Recommended Test Abridgements
394. al Variable Audio Oscillator Option 001 In the Frequency specification change 10 to 15 In the Total Harmonic Distortion specification change 600 kHz to 200 kHz and add the following lt 2 07 200 kHz to 600 kHz Pages 4 21 thru 4 23 paragraph 4 19 Under SPECIFICATIONS make the following changes Delete gt 35 dB below fundamental of 0 5 to 128 MHz Change 128 to 512 MHz to 0 5 to 512 MHz Change 35 dB to 30 dB in steps 2 3 two places and 4 seven places and 4 55 paragraph 4 32 Under SPECIFICATION make the following change to Option 001 Frequency Change 10 to 15 In step 4 change 10 to 15 4 56 paragraph 4 33 Under SPECIFICATION change 600 kHz to 200 and add the following lt K2 0 200 kHz to 600 kHz In step 2 change 600 kHz to 200 kHz end add the following 200 kHz to 600 kHz lt 2 0 Page 4 95 Table 4 4 Under paragraph number 4 19 change 35 dB to 30 dB eightplaces Page 4 90 Table 4 1 Under paragraph number 4 33 change 600 kHz to 200 kHz and add the following 200 kHz to 600 kHz 2 090 Add AIMP13 5040 0327 HOOD CONNECTOR Model 8640B Option 004 08640 90073 CHANGE 8 Cont d Page 6 34 Table 6 3 Change A26A2R35 to 0698 3447 RESISTOR FXD 422 OHM 1 0 125 W F TUBULAR Add A26A2R40 0698 3157 RESISTOR FXD 19 6K 1 0 125 W F TUBULAR Service Sheet 13 schematic Make the f
395. al to the RF oscillator frequency reaches the value corresponding to the geometric mean of the frequency band The reference voltage is determined by resistors R55 and R57 R58 adds smalt amount of hysteresis Transistor Ql comple ments the amplifier output Inverter U6A activates the low band relays ALOAIK1 and Service Sheet 10 and UGB activates the high band relays AIOAIK2 and K4 Service Sheet 10 The inverters are driven in complement except thal capacitors C18 and C19 held both inverters on simultaneously for a few milliseconds during a transition to provide a make before break action SERVICE SHEET 11 Cont d TROUBLESHOOTING H is assumed that a probiem has been isolated to the RF divider circuits as a result of using the troubleshooting block diagrams Troubleshoot hy using the test equipment listed below perform ing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital Voltmeter HP 84800 3484 if problems occur only on the lower bands an oscilloscope can be used to locate the defective RF circuit On the higher bands either a high frequency oscilloscope a sampling oscilloscope or a spectrum analyzer with a high impedance probe can be used Initial Test Conditions Top cover removed see Service Sheet G for removal procedure and A10 Divider Filtcr Assembly casting cover removed Service Sheet fo
396. an head screws which secure the 10 dB step attenuator to the instrument 5 While lifting the attenuator from the in strument disconnect printed circuit board con nectors P2 and A1P1 8 70 Model 8640B Option 004 6 Reinstall assembly by reversing the pro cedures in steps one through five Al Assembly Removal Procedure 1 Remove A19 OUTPUT LEVEL 10 dB Assem bly for the instrument 2 Remove OUTPUT LEVEL 1 dB and Vernier knobs from the front panel The knobs are secured to concentric shafts by setscrews in the knobs 3 Disconnect semi rigid coaxial cables W18 at 1 1 1 18 W10 A1A J 2 17 4 Remove 2 flat head screws which secure the front side panel item 14 Figure 6 1 5 Remove two flat head screws which secure the attenuator mounting plate 14 6 Carefully lift the Al OUTPUT LEVEL 10 dB Assembly from the instrument 7 Reinstall assembly by reversing the pro cedures in steps one through six Service SERVICE SHEET A Cont d Al Output Level Assembly Legend 21 Description Potentiometer Output Level Vernier Machine Screw 2 Lockwasher 2 Potentiometer Mounting Plate Lockwasher Hexnut Shaft Coupler Vernier Shaft Spacer 2 Switch Wafer Spacer 4 Switch Wafer Switch Wafer Machine Screw 2 gt Attenuator Mounting Place 1 dB Step Attenuator RF Connector RF Connector Spacer 2 Machine Screw 2 Switch Wafer RF
397. ance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 36 AM SENSITIVITY AND ACCURACY TEST Cont d 7 check indicated accuracy set test oscillator s amplitude controls for a reading of 9 90 AM on the 0 10 scale of generator s panel meter The DVM should read 180 mVrms 8 Check that trace is peaked on analyzer display 165 6 194 4 mVrms 8 Set the test oscillator s amplitude controls for the panel meter readings shown below The DVM should read as specified After each reading check that trace is peaked on analyzer display Panel Meter 7 a5 2 mVrms 5 LL 108 0 mVrms either 3 64 8 mVrms or 3 65 4 mVrms 2 43 6 mVrms 21 8 mVrms 30 be set on either the 0 10 scale or the 0 3 scale depending upon whether 30 is approached from above or below 4 37 PEAK INCIDENTAL PHASE MODULATION TEST SPECIFICATION Peak Incidental PM at 30 AM Less than 0 15 radians 0 5 to 128 MHz Less than 0 3 radians 128 to 512 MHz DESCRIPTION A vector voltmeter is used to compare the phase of the signal into the generator s modulation amplifier with the phase of the same signal modulated at a 0 1 Hz rate at the RF OUT port The signal is supplied by the generator s own oscillator and divider circuits and has low incidental PM See Table 4 1 Recommended Test Abridgements 4 62 Model 8640B Option 004 PERFORMANCE TESTS 4 37 PEAK INCIDENTAL PHASE MODULATION TEST EQUI
398. and lockwashers that secure coaxial connectors A8A1J1 and J2 12 Unsolder five wires from feedthroughs to left of A8A1 Assembly Remove 8 1 Removal 13 On bottom of 8 Assembly casting under Assembly remove hex nut and lock washer that secure A8A3J1 14 Unsolder five wires from feedthroughs to right of A8A3 Assembly 15 Remove two board supports and pan head screw with lockwashers Remove A8A3 Reassembly 16 Reassemble and reinstall A8 Assembly be reversing the procedures in steps one through 15 NOTES 1 When replacing the casting top cover be sure that the prongs on the brass RFI shield are behind the casting wall 2 The button shield must be carefully aligned to be sure that the buttons do not catch on the edges of the holes Check the action of all the COUNTER MODE buttons when the window is replaced SERVICE SHEET C Cont d Item Number 0 1 A8 Counter Lock Assembly Legend Reference Designator A8FL1 4 8 1 4 8 5 6 A8MP1 A8U1 6 A8MP2 A8MP3 A8MP4 A8MP5 A8L1 5 A8MP6 A8MP7 A8MP8 A8MP9 A8MP10 A8 MP11 A8MP12 A8MP13 A8MP14 A8MP15 A8MP16 A8MP17 A8MP18 A8A4 A8A2 A8A5 1 A8MP19 A8MP20 A8MP21 A8MP22 A8MP23 A8MP24 A8MP25 A8MP26 A8MP27 A8MP28 A8MP29 A8MP30 A8MP31 A8MP32 A8MP33 A8MP34 A8MP35 A8MP36 A8MP37 A8MP38 A8MP39 Description Feed Thru Filter Feed Thru Capacitor Feed Thru Ca
399. ange A7R45 to 26 1 Model 8640B Option 004 08640 90073 CHANGE 16 Cont d Service Sheet 20 Schematic Change A8A2C12 to 300pF Delete the line between A8A2U16B pins 4 and 5 Add a line from A8A2UI6B pin 4 to 5 2V Change the part number for A8A2U20 24 and U28 to 1820 1684 Service Sheet 2 Figure 8 68 with attached figure P O A8A2 ASSEMBLY Figure 6 68 P O 8 2 Counter Lock Board Assembly Component Locations P O Change 16 Service Sheet 21 Schematic Replace appropriate portion of schematic with attached partial schematic 7 58 Model 8640B Option 004 CHANGE 16 Cont d 20V R16 19 6K 20V 20V C5 A e 0 2 041 Thur 190 uF R29 6810 08640 90073 REFERENCE DESIGNATIONS WITHIM OUTLINED ama o m ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER e g RI OF ASSEMBLY 15 AIR DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS SHOWN wre eee ae ee Ce P O Figure 8 69 Counter Phase Lock Circuits Schematic Diagram P O Change 16 Model 8640B Option 004 08640 90073 CHANGE 16 Cont d 20 REFERENCE DESIGNATIONS WITHIN OUTLINED R16 ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER eg OF ASSEMBLY 19 6K 20V 15 DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS SHOWN R24 TAN iu 10K 9 3 IK i 07 9 FANS 1853 5
400. approximately 6 dB for each division of the output frequency down to the broadband noise floor of better than 100 amp EM lt 120 256 512 MHz BAND SPECIFICATION a 130 uy p 8 7140 150 230 300 350 400 450 500 550 CARRIER FREQUENCY MHz Figure 1 3 Specified Signal to Phase Noise Ratio at 20 kHz Offset vsus Carrier Frequency MHz Stated in a 1 Hz Bandwidth For lower bands phase noise decreases approximately 6 dB per fre quency division down to the broadband noise floor General Information 130 dB Hz This exceptional noise performance is also preserved in the phase lock mode and only slightly degraded during FM 1 26 Frequency Counter 1 27 The Signal Generator has a built in 550 MHz frequency counter and phase lock synchronizer The 6 digit light emitting diode LED display gives a normal resolution of 10 kHz at 500 MHz and 10 Hz at 500 kHz The resolution can be increased using the X10 or X100 EXPAND buttons near the display In the X100 EXPAND mode the res olution is 100 Hz at 500 MHz and 0 1 Hz at 500 kHz 1 28 This resolution combined with the high stability of the generator allows precise frequency selection and meaningful measurements on high performance receiver systems When selecting the external doubler band the counter displays the doubled output
401. are out of specification i e the first order sidebands will be uneven Counter External Sensi Omit steps 3 and Performance usually improves at lower tivity Test 4 frequencies 4 48 Internal Reference None Accuracy Test 4 49 Internal Reference Drift Omit test Drift is small in a normal lab environment Rate Stability Test Phase Lock Restabiliza Omit test Frequency error during the short lock acquisi tion Time Test tion time usually not significant 4 4 PERFORMANCE TESTS 4 12 BASIC FUNCTIONAL CHECKS DESCRIPTION A minimum of commonly available test equipment is used to check the overall basic functions of the Signal Generator EQUIPMENT Table 4 2 Recommended Test Equipment Basic Functional Checks Instrument Type Critical Specifications Suggested Models AC Voltmeter Accuracy 1 at 0 7 Vrms HP 400E or HP 34740A 34702A Frequency Counter Range 10 MHz HP 5326C Option 010 or Accuracy 0 1 ppm HP 5382A Option 001 Power Meter Frequency Range 10 MHz to HP 435A 8482A or 1 GHz HP 432A 478A Input Level gt 10 dBm Accuracy 1 Pulse Generator output IV into 50 2 HP 3311A or Range gt 2 kHz waveform HP 8011A not critical Spectrum Analyzer Range gt 100 MHz HP 8558 181 or Resolution Bandwidth HP 8553B 8552A 141T or gt 10 kHz to lt 100 Hz HP 8554B 8552A 141T Log and linear display PROCEDURE 1 Set the Signal Generator s controls as follows Return the controls to these
402. ary for correct test equipment operation COUNTER INPUT Do not apply a dc voltage or gt 15 dBm to COUNTER INPUT SEMI RIGID COAX While working with and around the semi rigid coaxial cables in the generator do NOT bend the cables more than necessary Do NOT torque the RF connectors to more than 2 INCH POUNDS viii TM 11 6625 2780 14 amp P SECTION 0 INTRODUCTION 0 1 Scope This manual describes Signal Generators SG 1112 V 1 U and SG 1112 v 2 U and provides instructions for operation and maintenance Throughout this manual the SG 1112 v 1 U is referred to as Model 8640B Option 004 and the SG II12 v U is referred to as Model 8640B Optin 001 A Manufacturer s Part Number to National Stock Number Coss Reference Index for the SG 1112 v I U and the SG II12 V 2 U is given in Section VI bf this manual 0 2 Indexes of Publications a DA Pam 310 4 Refer to the latest issue of DA Pam 310 4 to determine whether there are new editions changes or additional publications pertaining to the equipment b DA Pam 310 7 Refer to DA Pam 310 7 to deter mine whether there are modification work orders MWO s pertaining to the equipment 0 3 Maintenance Forms Records and Re ports a Reports of Maintenance and Unsatisfactory Equip ment Department of the Army forms and procedures used for equipment maintenance will be those described by TM 38 750 The Army Maintenance Management System b Report of Packaging and Handling
403. at least three inches of clearance at the rear and two inches clearance at the right side The clearances provided by the plastic feet in bench stacking and the filler strips in Installation rack mounting are adequate for the top and bottom cabinet surfaces 2 18 Bench Operation 2 19 The instrument cabinet has plastic feet and a foldaway tilt stand for convenience in bench operation The tilt stand raises the front of the instrument for easier viewing of the control panel and the plastic feet are shaped to make full width modular instruments self aligning when stacked 2 20 Rack Mounting 2 21 This instrument is supplied with a rack mounting kit This kit contains all the necessary hardware and installation instructions for mount ing the instrument on a rack with 19 inch spacing sed Figure 2 4 2 22 STORAGE AND SHIPMENT 2 23 Environment 2 24 The instrument should be stored in a clean dry environment The following environmental limitations apply to both storage and shipment Temperature 40 C to 75 Humidity lt 95 relative Altitude lt 25 000 feet 2 25 Packaging 2 26 Original Packaging Containers and materials identical to those used in factory packaging are available through Hewlett Packard offices If the instrument is being returned to Hewlett Packard for servicing attach a tag indicating the type of service required return address model number and full serial number Also mark the contain
404. at the low and high ends of each band Sde Table 4 Recommended Test Abridgements EQUIPMENT Frequency Counter 2 s HP 5327C PROCEDURE 1 Connect generators AUX RF OUTPUT jack located on rear panel to frequency counter s 50 ohm input after setting Signal Generator s controls as follows COUNTER MODE EXPAND off LOCK Source INT AM 2 4 3 My Gt Gow 0 we uw FM OFF G B i i i i 1 256 512 MHz FREQUENCY TUNE s CW FINE TUNE a s s a Centered RF ON OFF ON 2 Set FREQUENCY TUNE fully The frequency counter should read 230 MHz or less 230 0 MHz 3 Set FREQUENCY TUNE fully cw The frequency counter should read 550 MHz or greater 550 0 MHz 4 13 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 13 FREQUENCY RANGE TEST Cent d 4 Set RANGE as shown below and check frequency at high and low ends of each band Range MHz 512 1024 230 0 MHz 2550 0 MHz 128 256 115 0 MHz 2275 0 MHz 64 128 57 50 MHz 2137 5 MHz 32 64 28 80 MHz 268 70 MHz 16 32 14 40 MHz 234 30 MHz 8 16 7 200 MHz 217 10 MHz 4 8 3 600 MHz 28 500 MHz 2 4 1 800 MHz 24 200 MHz 1 2 lt 0 900 MHz gt 2 100 MHz 0 5 1 lt 0 450 MHz gt 1 070 MHz 4 14 FREQUENCY ACCURACY AND FINE TUNE TEST SPECIFICATION Accur
405. ate indication the LED display flashes The generator can be relocked by releasing the LOCK button and then relocking 1 34 The generator can be locked in the normal mode of the counter or in the X10 EXPAND mode if the OVERFLOW light is not on It is normally not possible nor recommended to lock in the X100 EXPAND mode or when counting external inputs Maximum resolution in the locked mode is 1 kHz at 500 MHz increasing to 1 Hz at 500 kHz 1 35 If an output frequency between adjacent counter indications is required a TIME BASE VERNIER is provided with a range of 20 ppm This fine tunes the internal crystal time base and sets the output frequency between adjacent counts 1 the least significant digits of the display This gives continuous coverage of all output frequencies even in the phase lock mode An UNCAL annunci ator near the vernier will light when this mode has been selected indicating that the counter display is incorrect 1 36 When phase locked the narrow bandwidth of the phase lock loop 5 Hz preserves full FM capabilities down to rates of 50 Hz and assures no degradation in noise from the unlocked mode residual FM is not changed by phase locking 1 37 Amplitude Modulation 1 38 AM is variable from 0 to 100 with the rates accuracy and low incidental FM required for the most stringent AM applications The front panel meter gives a direct readout of percent AM in either the internal or external mode and
406. ated Step Attenuator HP 355D Option H36 PROCEDURE 1 Connect equipment as shown in Figure 4 20 dfter setting Signal Generator s controls as follows Meter Function NE COUNTER MODE EXPAND LOCK Source AM MODULATION FM HT RANGE FREQUENCY OUTPUT LEVEL Switches OUTPUT LEVEL Vernier RF ON OFF AM off off INT AC Fully CW OFF 256 512 MHz 512 MHz 27 dBm CAL ON 2 Set test oscillator for a 1 kHz 636 39 mVrms signal as read on DVM 9096 AM Disconnect DVM from test oscillator leave oscillator connected to generator Connect DVM to spectrum analyzer s vertical output Set calibrated step attenuator to O dB 3 Set spectrum analyzer s resolution bandwidth to 300 kHz input attenuation to 20 dB frequency span per division scan width to 20 kHz tuning stabilizer on scale to linear and adjust center frequency and scale reference level controls to center the 512 MHz signal on the display Set frequency span per division to O Hz and display smoothing video filter to 10 kHz Peak the trace on the display with the center frequency controls set the trace to the center of the display with the reference controls 4 60 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 36 AM SENSITIVITY AND ACCURACY TEST Cont d NOTE Step 4 measure the analyzer s dc offset Voff and must be performed to ensure the accuracy of this test However if Voff for the analyzer b
407. ates as a 10 counter When pin 7 is high the counter initially at a count of nine overflows to zero when input T 4 goes low The other reset to nine inputs Rg at pin 6 are normally low bemg held low by the resistors R10 and R17 on their inputs When input T 4 goes high capacitors C21 and C22 ac couple the high into the reset to nine inputs which resets the counters to nine A short time laler pin 6 returns low When input T4 again goes low the counter again overflows to zero and the sequence repeats The Qy output then follows the T4 input in frequency In the unexpanded mode EXP 10 and EXP 100 are both high the output of NAND gate U1D is low and the output of inverter is high Both reset to nine inputs are high and counters U16 and 017 function as 1 counter In EXPAND X10 EXP 10 is low NAND gate UID is high inverter is low and counter U16 functions as a 10 counter In EXPAND X100 EXP 100 is low NAND gate U1D is again high inverter U7B is low and this time both counters U16 and U17 function as 10 counters The two counters in series divide the input frequency by 100 Table 8 7 Count Modes of Counters ASA3U13 and 0714 U13 and U14 Data Inputs COUNTER Count U14 MODE Condition Count Dp Preset Oy Dp Preset Count Count A H 25 7 B IL 32 Division 40 0 550 MHz 32 0 10 MHz H 25 Total Count 9 Preset Count of 914 x 1
408. ates the diodes of the ladder near it Transistor Q7 sets the voltage at the other end of the resistor diode ladder at one diode junction drop below ground it also temperature compensates the diodes of the ladder near it Transistor Q8 is a current sink Capacitor C6 frequency stabilizes Q7 and Q8 The diode cathodes in the ladder between Q7 and Q5 are at increasingly higher potentials As the voltage at the input to the ladder increases the diodes turn on consecutively and the FM Amplifiers A3 A5 A9 A13 SERVICE SHEET 6 Service SERVICE SHEET 7 Cont d impedance at the input lowers The Negative Shaping network is analogous to the Positive Shaping network except the polarity of all voltages is reversed the diodes are reversed all transistors are complemented and the shaping characteristic is modified Phase Lock Loop Filter A7 The Phase Lock Loop Filter is a 17 Hz active elliptic function low pass filter which filters the phase detector error voltage and drives the varactor diode anodes on Service Sheet 5 The phase lock input may vary from 5 to 15V the voltage at the varactor anodes varies from 13 6 to 16V with a quiescent value adjusted by R 19 TROUBLESHOOTING It is assumed that a problem has been isolated to the FM shaping circuits or to the phase lock loop filter as a result of using the troubleshooting block diagrams Troubleshoot by using the test equip ment listed below performing the intial test
409. ation If Indication is Abnormal 2 Vp p 1 Vpk at U1 pin 6 Check U1 and associated circuitry Initial conditions and settings Adjust MODULATION fora 2 Vp p 1 Vpk signal at AC IN POSITIVE PEAK DETECTOR A2U2 Tnitial conditions and settings Adjust MODULATION for 250 mVde al TP4 DC IN AUTORANGE COMPARATOR A4U9 Check U2 CR1 C5 and associated circuitry 4 5 Vde at A Check U2 and associated circuitry Adjust MODULATION for 350 at DC IN 100 mVde at A AMPL GAIN LOGIC A4U4A Initial conditions and settings Adjust MODULATION for 250 mVde at TP4 DC IN 4 0 Vde at U4A pin 8 Check U4 and associated circuitry Adjust MODULATION for 350 mVde at DC IN 50 mVde at 04 pin 3 Set Meter Function to FM 50 mVde at pin 3 RF Vernier A19A1 A26 SERVICE SHEET 16 Service Component or Circuit Meter Circuits Troubleshooting 2 of 2 Test Conditions and Control Settings METER DRIVE AMPL A4U1 Normal Indication Initial conditions and settings Adjust MOD ULATION for 977 mVde at TP4 DC IN 9 77 Vde at TP1 ES ADJ Adjust MODULATION for 300 mVde at TP4 DC IN 9 5 Vde at TP1 F S ADJ Model 8640B Option 004 If Indication is Abnormal Check U1 Q1 and associated circuitry SCALE Annun ciator Lamps 6 O 5 SCALE annun
410. ator Collins 479S 4A ILS Audio Signal Generator Tel Instrument Corporation T 20A VOR ILS Audio Signal Generator Model 8640B Option 004 1 18 Other significant features are extremely low noise built in phase lock and counter and front panel controls designed for operating convenience and flexibility 1 19 PERFORMANCE CHARACTERISTICS 1 20 Spectral Purity 1 21 The basic frequency source of the Signal Generator is a mechanically tuned high Q cavity oscillator that operates over the frequency range 230 550 MHz This oscillator has an inherent stability of better than 10 ppm 10 min and excep tionally low noise characteristics The lower 9 frequency ranges are obtained by dividing the basic oscillator frequency and filtering the unwanted harmonics Using this technique sub harmonic and non harmonic spurious signals are virtually elimin ated A band overlap of 7 to 10 adds conven ience when operating near the nominal band edges 100 l s N e i i NES EN 51351 WIDEBAN 450 MHz ell 1 BENE M w e p dB BELOW CARRIER IN 1 Hz BANDWIDTH 1 kHz 10 kHz 100 kHz 1 MHz Af Hz Figure 1 2 Measured Single Sideband Noise vs Offset from Carrier Stated in a 1 Hz Bandwidth at 256 and 512 MHz Carrier Frequencies on 256 512 MHz Band Markers indicate spec
411. ator Assembly 11 5 support A11MP6 Audio Oscillator Cover Circuit 11 1 4 Audio Oscillator Shaft 11 7 Spacer 11 8 Screw 11 9 Screw A11MP10 Washer 11 1 5 Setscrew A11MP11 Nut 11 12 Nylon Glide 11 6 Setscrew Retainer Ring Gear Gear Gear Gear Gear Potentiometer Flat Washer Coupler Switch Support Gear Support Adjustable Shaft Switch Shaft Omen gt NFO 13 HH D Figure 8 86 A9 Peak Deviation and Range Switch Figure 8 87 A 11 VariableFrequency Modulation Oscillator Option 001 Assembly Illustrated Parts Breakdown Illustrated Parts Breakdown 8 77 A9 and Al 1 Assemblies Removal and Disassembly SERVICE SHEET D Service SERVICE SHEET E Assembly Removal and Disassembly Pro cedure AIO Casting Cover Removal 1 3i Place instrument right side up and remove top cover see Service Sheet G Remove fourteen pan head screws with lock washers that secure casting cover to casting screws marked with asterisk on cover NOTE Note the location of the screws The long screws vary in length Lift cover from casting 10 2 Removal 4 Remove twelve pan head screws with lock washers that secure A10A2 Assembly to casting Remove A10A2 RF Divider Assembly and A10A3 Riser Assembly by lifting at the riser NOTES I The A10A2 Assembly can be extended fo
412. ator to remain warmed up the Auxiliary RF Output to remain on and the counter and phase lock to remain operating If it is desirable to switch both the modulator and the RF Oscillator off the RF ON OFF function may be easily modified see Service Sheet 5 in Section VIII RF OUT RF output through female connector Connector meets US MIL C 39012 50 ohm ac coupled source impedance Any interruption of the protective grounding conductor inside or out side the instrument is likely to cause damage to the instrument To avoid damage this instrument and all line powered devices connected to it must be connected to the same earth ground sed section o FINE TUNE fine frequency control Or REQUENCY TUNE coarse frequency control COUNTER INPUT external input to frequency counter impedance is 50 ohms Do not apply a dc voltage or gt 15 dBm to COUNTER INPUT Figure 3 2 Front Panel Controls Indicators and Connectors 2 of 4 3 3 Operation Model 8640B Option 004 FRONT PANEL FEATURES Range selects one of ten octave frequency bands The 512 1024 MHz Doubler position gives 256 512 MHz at RF OUT but the FREQUENCY MHz readings and FM meter indications are corrected for use with an RF doubler connected to RF OUT DEMOO OUTPUT output for a demodulated AM signal for precision measurement of percent AM and for sensing phase relationship of the output RF envelope and the input modulating
413. autoranges the 0 100 scale to 0 30 for improved nettability at low modulation depths 1 39 For precision measurement of AM the front panel DEMOD OUTPUT jack provides a demod ulated AM signal either 0 1 Vrms or 0 5 Vrms which is directly proportional to percent AM The DEMOD CAL label lists values of this voltage by which percent AM can be set very accurately within 1 with an ac voltmeter The label was prepared when the instrument was calibrated A new label should be prepared whenever the gener ator is recalibrated 1 40 DEMOD OUTPUT can also be connected to the Demod Input of some modulation sources for sensing the phase relationship of the output RF envelope and the input modulating signal 1 4 Model 8640B Option 004 1 41 AM up to rates of 50 kHz is possible depending on carrier frequency and modulation depths Distortion is specified at 400 Hz and 1000 Hz to be lt 1 up to 50 AM lt 3 to 90 AM Figure 1 4 shows measured AM distortion characteristics for other modulation frequencies Note that for 0 50 AM distortion is lt 1 to approximately 90 kHz for an output frequency of 200 MHz AM 70 A5 50 90 AM SPECIFIED AT 400 Hz AND 1 KHz RATES AM DISTORTION Ww 0 20 40 60 80 100 120 fc 8 512 MHz 0 10 20 30 40 50 60 fc 2 8 MHz 0 5 10 15 20 25 30 fc 0 5 2 MHz AM RATES kHz Figure 1 4 AM distortion us AM rate measured at 200 MH
414. bly reverse procedure given in steps one through five NOTE Check that the insulator between the right hand annunciators and the counter is properly in place to prevent shorting of the lamps Model 8640B Option 004 SERVICE SHEET G AQR5 DET OFFSET A2TP1 GND A2TP2 pc OUT A2TP3 ACINO 20v A2TP5 209 D A4R10 DRIVE OFFSET D A4R19 FS ADJ A4TP1 ADJ A4TP2 B 9 A4TPA DC IN A4TP5 GND QD astre 5 2 2 TIME BASE CAL 10 1 81 10 1 82 A OA1C83 10 1 84 A10A1L31 m A10A1L32 A10A1L33 10 1 37 A10A1L38 A10A1L39 A10A1L40 0000 A10A1L41 4 10 1142 10 11 43 10 11 4 Gi Al0A1L45 A18R2 5 2 ADJ QD 18 1 Fi 18 2 18 5 5 2 A18TP6 nq A20R8 44 6V ADJ A20R16 5 2V ADJ A20TP1 r2 AZ0TP4 44 6V A20TP5 RO A20TP6 F1 A20TP7 F1 A20TP10 5 2V A22R7 20V ADJ A22R19 20V ADJ A22TP1 F2 A22TP2 F2 22 20v A22TP6 F1 A22TPT Fl 99 9 20V A26A9R19 AM QD A26A2TP1 26 2 2 A26A2TP3 A26A2TP4 A26A2TP5 26 2 6 A26A2TPT A26A2TP8 A96AARI A26A4R2 A26A4R12 A26A4TP1 26 2 26 4 AZGAATPA 26 A26AATPG 26 A26A4TP8 A26A8R3 A26A8R6 26 8 8 A26A8R10 A26A8R15 26 851 26 8 1 A26A8TP2 A26A8TPS AM IN GND AM OUT PUL IN
415. both Ro inputs are high the outputs clear to zero The clear function overrides the clock Similarly the two ANDed set or reset to nine R9 inputs set the outputs to the nine count If all reset to zero and reset to nine inputs are simultaneously high the reset to nine overrides the reset to zero 8 62 Programmable Counter The programmable decade counter shown in Figure 8 13 operates similarly to the basic decade counter when the load LD input is high The counter shown has only a single clear CLR input which is active low When the load input is low the information at the data or preset inputs DA DB Dc and is transferred to the outputs at the next high going clock T input The outputs remain in the preset state until the load input returns to a high and the Service trigger T or clock input again goes high at which time the count increments by one The counter may be preset to a count greater than nine but in such cases the count proceeds as shown in the state diagram BINARY SHIFT REGISTER OUTPUT OUTPUT STATE OUTPUT STATE BEFORE CLOCK AFTER CLOCK SER B C D The state of the serial SER input The state of the serial SER The state of the serial SER input Figure 8 11 Binary Shift Register BASIC DECADE COUNTER SCALER gt 00 7 4 C O Owm ee KS OOOO O OQO m RK OCF e ORF gt
416. both set S inputs are high Between the low occurrences of COUNTER LOAD and TIME BASE the Q outputs of both U26A and U26B are low If COUNTER LOAD goes high first the Q output of U26B goes high first When TIME BASE goes high the Q output of U26A goes high Both inputs of NAND gate U15C are now high so the output goes low and after a slight delay through resistor capacitor network and C1 and OR gate U14A both flip flops are cleared The Q output of U26B remained low longer than the Q output of U26A If a high on TIME BASE had occurred first the opposite would have been true If both occur simultaneously both outputs remain high for an equal duration The Q output pulses of U26 A and U26B are increased in duration by a pulse width multiplier and then drive current sources which charge and discharge a storage capacitor When the Q output of U26B goes low it turns on transistor switch Q8 Capacitor is at 10V when Q8 is off because the inverting input of amplifier U2Z9A SERVICE SHEET 21 Cont d is at the output of U29A is also at 10V since with Q8 off no current flows through R7 When Q8 goes on C2 rapidly discharges through 98 The output of U29A goes high to about 20V and remains at that voltage until Q8 switches off and C2 charges slowly to about 10V Current source Q7 is on when the output of U29A goes high In a similar manner amplifier U29B goes high and turns on current source Q12 when the Q output of U26A goes
417. cated in front of A26 Assembly 11 Remove four hex nuts and lockwashers that secure coaxial connectors A10A1JI through JA 12 Turn instrument right side up Unsolder three feedthroughs at rear center of Al OAI Assem bly located to right of two toroid inductors and to left of relay CAUTION Be sure the terminals have been com pletely resoldered 13 Remove the ten pan head screws with lock washers that secure 10 1 Assembly to casting Remove NOTE If necessary the bottom casting cover can be removed by removing four allen screws with lockwashers Reassembly 14 Reassemble A10 Assembly by reversing the procedures in steps one through 13 Model 8640B Option 004 SERVICE SHEET E Cont d Item Number nM 10 Divider Filter Assembly Legend A10MP1 10 2 A10A1MP1 19 4 A10A1MP2 A10A1MP3 10 5 10 10 7 10 8 A10A1MP4 10 1 5 A10MP9 A10MP10 A10A1MP6 A10A1MP7 A10A1MP8 A10A1MP9 A10A1MP10 10 1 A10A3 A10A2 1 11 10 12 10 1 11 A10MP13 10 14 10 2 10 15 A10A1MP13 10 16 A10MP17 A10A1MP14 A10MP18 10 19 10 181 6 Description Designator A10A1FL1 2 3 Feed Thru Filter Yellow P C Board Guide Green P C Board Guide Blue P C Board Guide Detent Pin RFI Braid Detent Roller Detent Spring Spring Shield No Spring
418. cathodes are switched by FM Enable reed relay K1 either to R39 when the FM is disabled or to the amplifier output when the FM is enabled The relay is energized only when the FM switch is not OFF and when the PEAK DEVIATION and RANGE switches are set to an allowable combination The maximum peak FM deviation possible is 170 of the output frequency at the low end of a range e g 2 56 MHz deviation on the 256 512 MHz range The PEAK DEVIATION and RANGE switches however can be set to combinations that exceed this e g 2 56 MHz deviation on the 2 4 MHz range For such unallowable combinations the FM amplifier is disabled by A5K1 on Service Sheet 6 the varactor diode cathodes are grounded by A7K1 the meter input is opened by A5K1 and the REDUCE PEAK DEVIATION annunciator lamp A6DS2 is turned on see Service Sheet 8 The interaction of the PEAK DEVIATION switch and the RANGE switch is accomplished by differential gearing between the two switches Positive and Negative Shaping A7 The Positive Shaping network presents an increasingly lower impedance to the input as the input voltage increases Resistors R11 R12 and R13 set the base voltage of transistor Q5 and Q5 sets the voltage supply to the resistor diode ladder Transistor Q6 supplies most of the current Capacitor C5 keeps the base of Q5 at an ac ground potential Diode CR9 protects Q6 in the event of a shorted 20V supply The base emitter junction of Q5 tempera ture compens
419. cavity into two buffer amplifiers by loops which protrude into the cavity Buffer Amplifiers A3A1A2 and A3A1A3 Operation of the Divider Filter Buffer Amplifier and the Counter Buffer Amplifier is essentially the same The Divider Filter Buffer Amplifier drives the Modulator Preamplifier The Counter Buffer Amplifier drives the counter input The main function of these amplifiers however is to isolate the RF Oscillator from external circuits Transistors Q1 and Q2 are two common emitter amplifier stages The base of Q1 is de grounded through the coupling loop T1 Emitter current is established by resistors R3 and R4 capacitor C2 at bypasses R4 The gain of Q1 is set by R1 R2 R3 and R6 also C8 Divider Filter Buffer Amplifier only The collector of Q1 is Counter Lock Circuits Troubleshooting SERVICE SHEET 4 Service SERVICE SHEET 5 Cent d at coupled to the base of Q2 by capacitor C4 Operation of transistor Q2 is similar to Q1 In the Counter Buffer Amplifier only resistors R10 R11 and R12 form a 10 dB pad to reduce the output level and increase the output to input reverse isolation The amplifier board is secured through slotted holes by two screws By loosening the screws and sliding the board the amount of coupling loop protruding into the cavity can be altered and the amplifier output level varied TROUBLESHOOTING General The oscillator transistor buffer amplifiers and external circuits of the A3 RF Oscil
420. ce Model 8640B Option 004 a SEE NOTE E EID AND DIVIDEREILTER ASSY QMADHOS Le EE ed E ee ee P O AIOA3 RISER ASSY 08640 80072 RF DIVIDER ASSY 08640 60023 LOIL T aan ee U S ssa PR ear med MK mild ee a em IER 1 4 mannin REFERENCE DESIGHATIONS WITHIN tomm zeamet seus PIO RISER ASSY Mn SUFFER ta deeem 179 2565 R O n qt grau SN wor is CLUDES ASSEMBLY WUASER p RI DF A FILTER TO DIVIDER 0860 6022 FR 4 oe MEL E AIRI DESIGNATIONS OF OTHER COMPONENTS ARE gt 1 NEA DAPLETE AS SHOWN A Po d 89 178 256 MHz OUT 2 EAE o Ba Ue FROM RF OSCILLATOR BT E WS Q 1 d 6 15 32 MHz OUT PI o 8 16 MHz OUT M sy n SCHMITI TRIGGER NE ME 5 5 O 4 T i ST R6 i BS ry civ 2Y bur Ru ii d 2 522 h 12 Dr oa z Md Q LOW BAND 0 gt e mS u a MF NOTE 3 M 3 1826 0013 QS 70 1 E fi 1854 0071 Rist pn 10 2610 a 1 dg i 1470 a 1 cre 1000 CR 1 1 22 WK I CRS Tee SEE NOT
421. ce 50 ac coupled 40 Vdc maximum VSWR 2 0 on 3V and IV output ranges 1 3 on all other ranges DESCRIPTION A tracking generator is used as an external 509 signal source to feed a VSWR bridge The output port of the bridge is connected to a spectrum analyzer The through port of the bridge is connected to a short circuit to establish a reference then to the generator output Return loss versus frequency is displayed on the spectrum analyzer See Table 4 1 Recommended Test Abridgements 10 dB ATTENUATOR VSWR BRIDG MODEL 8640B OPTION 004 Ires RF OUT ACKING GENERATOR J 3 COAXIAL SHORT STEP 4 Figure 4 14 Output Impedance Test Broadband EQUIPMENT Tracking Generator HP 8444A Spectrum Analyzer HP8554B 8552B 141T VSWR Bridge Wiltron 60350 Coaxial Short oe MIS 11512A 10dB Attenuator HP 8491A Option 10 PROCEDURE 1 Connect equipment as shown ip Figure 4 14 after setting Signal Generator s controls as follows amp ow ose we X w X X e dE dE OC b ORE FM 363 OFF RANGE 256 512 MHz FREQUENCY TUNE wv o s 5 OUTPUT LEVEL Switches Ko d o3 X ede amp 16 dBm OUTPUT LEVEL Vernier HM M o e c 22 2 CAL RF ON OFF 6o OFF 4 49 Performance Tests Model 8640B Option
422. ce FM vernier until meter reads 5 kHz the annunciator should go out Check that RANGE is set to 0 5 1 MHz and set PEAK DEVIATION to 10 kHz the REDUCE PEAK DEVIATION annunciator should light and the meter should indicate 0 Set RANGE to 1 2 MHz the annunciator should go out and tum the PEAK DEVIATION vernier full counterclockwise the meter should indicate 0 on the 0 10 SCALE Modulation Oscillator p Using the BNC to BNC cable connect FM OUTPUT to COUNTER INPUT Set COUNTER MODE EXPAND X100 and Source to EXT 0 10 Set AUDIO OUTPUT LEVEL o to 1V and MODULATION FREQUENCY in turn to 400 Hz and 1 kHz the FREQUENCY readout 0 should display approximately 0 000400 and 0 001000 MHz Figure 3 5 Operator s Checks 4 of 5 3 11 Operation Model 8640B Option 004 OPERATOR S CHECKS Demodulated Output q Change the controls as follows Meter Function bok AOR dh ave MODULATION fg de RE eR ee 9 ART AMG x ee xeu X ex cu 2 FM zou veu Bane vg RS SOE OUTPUTLEVEL1db OUTPUT LEVEL 10d4B 10dBm Connect a de voltmeter to DEMOD OUTPUT If the generator s internal AC DC switch 26 851 is in the DC position the voltmeter should indicate approximately 1 4 Vdc If the AC DC switch is in the AC position the voltmeter should indicate approximately 0 Vdc Connect ac vol
423. ch each other Adjustments Model 8640B Option 004 5 27 3 10 11 ADJUSTMENTS VARIABLE FREQUENCY MODULATION OSCILLATOR ADJUSTMENT OPTION 001 Cont d Turn trim capacitors 2 and C3 fully cw NOTE Turning C2 ccw decreases the output voltage while raising the frequency Turning C3 ccw increases the output voltage while raising the frequency Set Signal Generator s controls as follows AME MeV ER wo p 2 MODULATION FREQUENCY Switch X100 MODULATION FREQUENCY Vernier Fully CCW FM OFF AUDIO OUTPUT ou ne on Fully Connect DVM to OSC OUT test point 11 4 The DVM should read 1 6 0 3 Vrms 1 3 19 Vrms Connect frequency counter to AM OUTPUT jack The counter should read 1 8 0 2 kHz 1 6 2 0 kHz Set MODULATION FREQUENCY vernier fully cw and adjust trim capacitors A11C2 and C3 until voltage level at is within 0 1 Vrms of level read in step 5 and frequency at AM OUTPUT is 21 1 kHz Set MODULATION FREQUENCY vernier for a frequency counter reading of 2 0 0 01 kHz Loosen setscrews in gear that meshes with frequency dial gear vernier Rotate dial gear so that dial reads 20 at the cursor and tighten setscrews in gear The frequency counter should read 2 0 0 01 kHz when dial reads 20 at the cursor Record voltage level at Vrms Set MODULATION FREQUENCY verni
424. ck components for correct resislance Check A22U1 and supply load circuits Correct operation and resistance Replace faulty component 20V REGULATOR Remove A22 assembly Measure resistance from A17XA22 7 to chassis ground 261 Check supply load circuits for shorl Open pins 7 and 24 on extender board Extend A22 assy and check voltage from A22TP5 Lo ban Check A22U2 and supply load circuits r20 01V Check diodes and transistors For correct operation with vollage applied Check components for correct resistance Replace faulty component 5 2V REGULATOR Remove A20 assy Measure resisLance from A17XA20 4 7 Lo chassis ground 230 Check supply load circuits for short Counter Phase Lock Circuits 2 SERVICE SHEET 21 Service SERVICE SHEET 22 Cont d Power Supply Troubleshooting 2 of 21 Component Test Conditions and or Cireuit Control Settings Norma Indication Open pins 4 27 7 and 24 on 5 2 0 15V extender hoard Extend A20 assy and check voltage from 5 2V REGULA TOR Cont d Model 604UB Option UU If Indication is Abnormal Check A20UI and supply load circuits 20 board pin 1 to A20TPLO Check diodes and transistors Correct operation and for correct operation with resistance voltage applied Check com ponents for correct resistance 44 6 REGU
425. coupled or internal from the modulation oscillator In the pulse modulation mode external modulation pulses switch the modulator off and on Amplitude leveling is maintained in this mode by storing the detector output between pulses The detector output is also supplied to a buffer demodulation amplifier A selection switch on the buffer amplifier provides selection of ac only O 5 Vrms or ac 0 1 Vrms plus dc at DEMOD OUTPUT The 10 dB and 1 dB RF step attenuators further control the output level The meter circuits moni tor either the detector output and hence the output level the positive peak of the AM modul ating signal calibrated to give AM or the positive peak of the FM modulating signal cali brated to give peak deviation Counter Lock Circuits Service Sheet 4 In the internal count mode the counter always counts the 256 512 MHz signal from the RF oscillator The time base period is adjusted to give the correct frequency reading for the different frequency ranges In the external count modes external input signals are counted directly In the phase lock mode the counter compares the count of the RF signal against the count just before acquisition of phase lock and adjusts the frequency of the RF oscillator to make the counts coincide The counter time base reference may be either the internal or an external 5 MHz TROUBLESHOOTING Use the overall block diagram to isolate the trouble to a specific secti
426. ct an attenuator which determines the overall gain and the negative shaping network Service Sheet 7 which has only a small effect The effect of the shaping networks is small because voltage swings are small and the tuning characteristic of the varactor diodes is fairly linear over the narrow range of operation For O dB gain the amplifier is in a unity gain configuration the positive shaping network and attenuator have no effect and the negative shaping network has a small effect For gains greater than O dB the attenuator is in the feedback path and the gain is inversely proportional to the feedback attenuation The positive shaping network is also in the feedback path and for large positive voltage excursions it increases the feedback attenuation and hence increases the amplifier gain The negative shaping network is in the output path and for large negative voltage excursions the output attenuation is increased and the overall amplifier gain decreases Attenuator A9 Before entering the feedback path the FM Amplifier output passes through an attenuator formed by resistors R4 through R7 which reduces the open loop gain of the amplifier when only small closed loop gain is needed The gain control attenuator used in the feedback or output of the amplifier is formed by resistors R12 through R22 TROUBLESHOOTING It is assumed that a problem has been isolated to the FM amplifier circuits as a result of using the troubleshooting block
427. cule line on analyzer s display below 97 dBm from 400 MHz to 600 MHz 97 dBm 5 Set the analyzer s center frequency controls to 700 900 and 1100 MHz Hold the end of the loop antenna cylinder in contact with all surfaces of the generator at each frequency setting All signals and noise should be below the 27 dB graticule line below 97 dBm from 600 MHz to 1200 MHz 97 dBm 4 32 INTERNAL MODULATION OSCILLATOR TEST SPECIFICATION Standard Frequency fixed 400 Hz and 1 kHz 2 Output Level indicated 10 mVrms to 1 Vrms into 600 ohms Option 001 Frequency variable 20 Hz to 600 kHz 10 in 5 decade continuous bands plus freed 400 Hz and 1 kHz 3 Output Level 20 mVrms to 3 Vrms into 600 ohms DESCRIPTION The internal modulation oscillator output is measured with a voltmeter and a frequency counter to verify its frequency range and accuracy and its level See Table 4 1 Recommended Test Abridgements 4 53 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 32 INTERNAL MODULATION OSCILLATOR TEST Cont d MODEL 86408 OPTION 004 DIGITAL VOLTMETER AM PE FREQUENCY COUNTER FEEDTHROUGH Figure 4 16 Internal Modulation Oscillator Test Setup EQUIPMENT Frequency Counter HP 5327 Digital Voltmeter a HP 3480D 3484A Option 043 600 Ohm Feedthrough Termination E HP 11095A PROCEDURE 1 4 54 Connect equipment as shown ip Figure 4 16 after setting Sign
428. d and then the counters are cleared When TIME BASE goes high the count begins again Shaping and Input Gating Gates U15A U2B U2C U14D and U13A shape the input waveform into pulses of about 30 nanoseconds duration The circuit uses gate delays and positive feedback to shape the pulses NAND gate U2D inhibits the input to the counter when TIME BASE is low D flip flop U1A and gates U14B and U15B also shape the input pulses and further assure that the pulse is either of full duration or is absent in the event that TIME BASE goes low while an input pulse is high The output of gate U17C is normally low and the output of gate U16B is normally high the resistor R45 and inductor L1 hold the inputs low When the TIME BASE goes low the output of inverter U4E goes high The output of U16B goes low until resistor R45 discharges capacitor C10 and the output returns to a high While U16B is low the low enable EN inputs of the storage buffers allow the data inputs to transfer to the outputs When the output of U16B goes high the output of U17C goes high until inductor L1 charges C11 and the output retums to a low While U17C is high the counters are cleared When TIME BASE goes high the outputs of U16B and U17C remain unchanged Overflow Detector The overflow detector lights OVER FLOW lamp 8 4052 whenever a carry is generated by counter U19 in which case the count has exceeded the number of digits available in the display The output
429. d change less than 800 Hz 800 Hz Model 8640B Option 004 Adjustments ADJUSTMENTS 5 40 PRELIMINARY FM ADJUSTMENTS Cont d 11 To set VAR pot VARACTOR BIAS A7R19 connect DVM to VARACTOR ANODE test point A7TP2 and check that voltage is 14 70 0 01 Vdc If it is not adjust A7R19 until it is 12 Perform the FM Linearity Adjustment 5 39 5 41 FM LINEARITY ADJUSTMENT REFERENCE Service sheet 7 DESCRIPTION The positive and negative shaping circuits are adjusted to match the characteristics of the varactors in the RF oscillator The reference output of a variable phase generator is used to drive the Signal Generator s FM circuits its variable phase output is used to drive an oscilloscope s horizontal circuits and the FM linearity circuit A discriminator is used to demodulate the FM and the demodulated signal is subtracted 1 summed 180 out of phase from the modulation signal in the FM linearity circuit and fed to the oscilloscope s vertical circuits The shaping circuits are then adjusted for the flatest trace possible on the oscilloscope s display A reference signal generator and a mixer are used to down convert the test generator s output to within the range of the discriminator NOTE The Preliminary FM Adjustment 5 40 should be made before performing this adjustment A simpler method for adjusting FM linearity using less test equipment is presented in paragraph 5 42 This alternate metho
430. d government manuals Why do I do it I am tired of sleazy CD ROM sellers who take publicly available information slap watermarks and other junk on it and sell it Those masters of search engine manipulation make sure that their sites that sell free information come up first in search engines They did not create it They did not even scan it Why should they get your money Why are not letting you give those free manuals to your friends I am setting this document FREE This document was made by the US Government and is NOT protected by Copyright Feel free to share republish sell and so on I am not asking you for donations fees or handouts If you can please provide a link to liberatedmanuals com so that free manuals come up first in search engines lt A HREF http www liberatedmanuals com gt Free Military and Government Manuals lt A gt Sincerely Igor Chudov http igor chudov com
431. d however is not as effective for locating the source of FM distortion when used in trouble shooting 5 35 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 41 FM LINEARITY ADJUSTMENT Cent d REFERENCE SIGNAL GENERATOR FM DISCRIMINATOR FM LINEARITY CIRCUIT 20 dB AMPLIFIER OUTPUT Figure 5 11 FM Linearity Adjustment Test Setup EQUIPMENT Reference Signal Generator HP 8640A Mixer 4 ewe Eine S HP 10514A FM Discriminator er HP 5210A Filter Kit for Discriminator HP 10531A Variable Phase Generator oo wrap vog HP 203A Oscilloscope HP 180A 1801A 1820C FM Linearity Circuit HP 08640 60503 20 dB Amplifier ow HP 465A NOTE The reference signal generator should have low RF drift low residual FM performance approximately equal to the Model 8640 and be capable of producing 355 MHz at 7 dBm 5 36 Model 8640B Option 004 ADJUSTMENTS 5 41 F M LINEARITY ADJUSTMENT Cont d PROCEDURE Adjustments 1 Connect equipment as shown ip Figure 5 11 after setting Signal Generator s controls as follows Meter Function COUNTER MODE EXPAND Off LOCK Sound NT uec RC Ad wh wy we Xe 9 cx oc x x a FM 5 ue ea A hee PEAK DEVIATION LINT 2 56 MHz PEAK DEVIATION Vernier
432. d read about 0 750000 MHz the reading should shift one place to the left Set COUNTER MODE EXPAND to X100 FREQUENCY should read about 500000 MHz the reading should shift one additional place to the left with the decimal point and the seven no longer displayed the OVERFLOW annunciator lamp should light Set COUNTER MODE EXPAND to OFF buttons out With RANGE set as follows FREQUENCY should read approximately as shown RANGE MHz FREQUENCY MHz 0 5 1 0 75000 1 2 01 5000 2 4 03 0000 4 8 06 0000 8 16 12 0000 16 32 024 000 32 64 048 000 64 128 096 000 128 256 0192 00 256 512 0384 00 512 1024 0768 00 Phase Lock f Set RANGE to 256 512 MHz Note that the right hand digit on the FREQUENCY display flickers between two digits Set COUNTER MODE LOCK e to ON the flickering should stop Slowly adjust FINE TUNE the FREQUENCY reading should not change Adjust FREQUENCY TUNE the frequency display should flash at about a 2 Hz rate and the reading should change the reading should follow FREQUENCY TUNE Figure 3 5 Operator s Checks 2 of 5 Operation Model 8640B Option 004 OPERATOR S CHECKS RF Output 5 Set COUNTER MODE LOCK to OFF and Source Qo to EXT 0 550 Adjust FREQUENCY TUNE D until FREQUENCY reads 0384 00 MHz Step through the ranges as specified in step e setting the COUNTER MODE EXPAND and Source EXT controls to obtain appropriate resolution FREQUENCY should read approximately as sh
433. dB per division Set reference level controls to put peak of the signal at top log reference graticule line on the display To check external sensitivity set test oscillator for a 0 7071 Vrrns signal read on DVM at approx imately 2 079 kHz Set test generator s FM switch to AC and fine tune test oscillator s frequency for the first carrier null on analyzer s display at least 50 dB below the top graticule line With the frequency counter measure frequency of modulating signal It should be 2 079 kHz 6 i e 5 kHz 6 peak deviation 12204 kHz Use the procedures given above to check the remaining bands by setting the test Signal Generator s RANGE switch as shown below As shown in steps 1 through 4 on each range set FM to OFF and tune the generators for a 1 MHz difference Set the reference on the analyzer set FM to AC with a 0 7071 Vrms modulating signal at approximately 2 079 kHz and tune the modulating signal s frequency for the first carrier null The signal s frequency should be as shown RANGE FREQUENCY Reference Generator Mod Signal Frequency MHz TUNE Frequency kHz 128 256 64 128 32 64 16 32 8 16 4 8 2 4 1 2 4 83 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 45 FM SENSITIVITY AND ACCURACY TEST Cont d 6 To check indicated accuracy set test Signal Generator s RANGE control to 256 512 MHz and FREQUENCY TUNE to 500 MHz Set reference signal generator for a 501 MHz
434. dBm 11 dBm 10 dBm 1 step ccw 10 dBm from fully cw 9 dBm 8 7 dBm 6 dBm 5 dBm 4dBm 3 dBm 2 dBm 1dBm 0 dBm 1 dBm 2 dBm 4 Set step attenuator to 70 dB Set spectrum analyzer center frequency to 512 MHz resolution bandwidth to 1 kHz frequency span per division scan width to 0 5 kHz input attenuation to 0 dB tuning stabilizer on display smoothing video filter to 100 Hz 2 dB per division vertical log display with a 20 dBm reference level 5 Connect attenuator to generator s RF OUT without disturbing generator s controls Center signal on analyzer s display Consider the center horizontal graticule line equivalent to 11 dBm with a panel meter reading of 1 dB then with the vertical scale reference vernier control set the signal peak to be equal to the last measured level on the power meter NOTE If for example the last power meter reading was 11 4 dBm the vertical scale resolution is 2 dB division therefore the signal peak should be 0 4 dB or 0 2 division below the center reference graticule line 4 36 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 25 OUTPUT LEVEL ACCURACY TEST Abbreviated Cont d 6 Step Signal Generator s OUTPUT LEVEL 10 dB switch and analyzer s vertical scale log reference level control as shown in the following table Verify that the amplitude falls within 2 0 dB 1 division of the center reference graticule
435. dc coupled with no magnification Set the vertical input to dc Adjust the vertical and horizontal sensitivity y to form a Lissajous pattern which fills the display as shown in Figure 4 24 Figure 4 24 Lissajous Display 4 70 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 39 AM PHASE SHIFT TEST Cont d 3i To increase the reading sensitivity set the horizontal magnifier to X10 and increase the vertical sensitivity by a factor of 10 The phase shift is equal to sin B A 1 B 80 A is 8 divisions multiplied by 10 The Y axis crossings of the Lissajous pattern should have a separation B of less than 4 2 major divisions less than 3 4 2 divisions Set the test oscillator frequency to 1000 Hz Increase the oscilloscope s vertical sensitivity by a factor of 10 The Y axis crossings of the Lussajous pattern should have a separation B approximately equal to that of step 5 and be less than 4 2 major divisions less than 0 3 4 2 divisions Set the test oscillator frequency to 9 kHz Decrease the oscilloscope s vertical sensitivity by a factor of 10 Note the separation B of the Y axis crossing of the Lissajous pattern Set the test oscillator frequency to 11 kHz The separation B of the Y axis crossings of the Lissajous pattern should be within 2 8 divisions of that in step 7 less than 2 difference 2 8 divisions 10 If the Signal Generator is used
436. designations MP75 thru MP80 are not assigned Page 6 43 Table 6 3 Change W13 to 08640 60125 CABLE ASSEMBLY PULSE IN Service Sheet 5 component locations Add the following figures A3A1A3 A3A1A3 Counter Buffer Amplifier Figure 8 22B A3A1A2 Divider Filter Buffer Board Assembly Errata Amplifier Board Assembly Errata Service Sheet 5 Schematic On the A3A1A3 and A3A1A2 assemblies change the indicated voltage at the junctions of R4 and R9 to 5 2V The recommended replacement for A3Q1 is transistor 5086 4282 see Change 11 7 22 Model 8640B Option 004 08640 90073 ERRATA Cont d Service Sheet 8 schematic Make the following changes to the A7 assembly Change the indicated voltage at U2B pin 7 to 1 05V Change the indicated voltage at U2A pin 4 to 1 05V Service Sheet 9A component location Delete Al1 MP6 2 places MP7 MP8 and MP9 Delete AIMP2 AIMP3 AIMPA and 5 2 places Service Sheet 11 schematic On the A10A2 assembly add an asterisk after R3 Service Sheet 13 schematic On the A26 assembly change the part number for U1 to 08640 67006 service Sheet 18 schematic On the A8AT assembly make the following changes Add an asterick after R7 Add the following circuitry between the junction of CR4 and CRS and K2 R13 233 Service Sheet 19 Schematic A8A3UI U11 and U13 thru 017 Recommended replacements for these parts and
437. diagrams that follow it to isolate a problem to a particular assembly or circuit The troubleshooting information on Ser vice Sheet 1 explains how to use the block diagrams 8 11 Circuit Level Troubleshooting Once a prob lem has been isolated to a particular assembly or circuit the text and a table on the service sheet that documents that circuit give detailed trouble shooting information for the circuit 8 12 RECOMMENDED TEST EQUIPMENT 8 13 Test equipment and test equipment acces sories required to maintain the Signal Generator are listed in and 1 3 Refer to the MAC Appendix I for Army test test equipment requirements 8 14 SERVICE AIDS 8 15 Posidriv Screwdrivers Many screws in the instrument appear to be Phillips but are not To avoid damage to the screw slots Posidriv screw drivers should be used 8 16 Service Kit The following parts can be ordered for use in a service kit for the generator Before ordering check to ensure that they are not on hand most of them are common to service kits for other Hewlett Packard instruments 8 1 Service HP 1250 0827 HP 11592 60001 HP 5060 0256 HP 0403 0115 ISMC Adapter 2 Test Cables SMC to 1 Extender Board 20 pins 2 Bumpers for Board 8 17 Hardware Kit The HP 08640 60095 Hard ware Kit contains miscellaneous mechanical spare parts for the generator such things as nuts bolts screws and washers Figure 8 1 Signal Generator
438. djustment maintenance and repair of the opened instrument under voltage should be avoided as much as possible and if inevitable should be carried out only by a skilled person who is aware of the hazard involved Capacitors inside the instrument may still be charged even if the instrument has been dis connected from its source of supply FUSES Make sure that only fuses with the required rated current and of the specified type normal blow time delay etc are used for replacement The use of repaired fuses and the short circuiting of fuse holders must be avoided Cautions Warnings CAUTIONS GROUNDING Any interruption of the protective grounding conductor inside or outside the instrument is likely to cause damage to the instrument To avoid damage this instrument and all line powered devices connected to it must be connected to the same earth ground seq LINE VOLTAGE Be sure to select the correct fuse rating for the selected line voltage see LINE VOLTAGE SELECTION in Section Il fuse ratings are listed on the fuse compartment To prevent damage to the instrument make the line voltage selection BEFORE connecting the line power Also ensure that the line power cord is connected to a line power socket that is provided with a protective earth contact SAFETY To avoid the possibility of damage to test equip ment read completely through each test before starting it Make any preliminary control settings necess
439. djustment maintenance and repair of the opened instrument under voltage should be avoided as much as possible and if inevitabie shoutd be carried out only by a skilled person who is aware of the hazard involved Capacitors inside the instrument may still be charged even if the instrument has been disconnected from its source of supply Make sure that only fuses with the required rated current and of the specified type normal blow time delay etc are used for replacement The use of repaired fuses and the short circuiting of fuseholders must be avoided Whenever it is likely that the protection has been impaired the instrument must be made inoperative and be secured against any unintended operation Any interruption of the protective grounding con ductor inside or outside the instrument or disconnection of the protective earth terminal is likely to make the instrument dangerous Intentional interruption is pro hibited Power Supply Troubleshooting 1 of 2 Component or Circuit Test Conditions and Control Settings Normal Indication if Indication is Abnormal Remove A22 assembly Measure resistance from A17X A22 1 to chassis ground 20V REGULATOR 2309 Check supply ioad circuits for short Open pins 5 and 26 on extender board Extend A22 assembly and check voltage from A22 board pin 5 to A20TP9 Check diodes and transistors far correct operation with vollage applied Che
440. e 0 0 INT RANGE 512 1024 MHz TIME BASE INT EXT rear panel INT Counter Time Base Troubleshooting Component Test Conditions and or Circuit Control Settings Normal Indication if Indication is Abnormal TIME BASE REF Initial conditions and settings ERENCE CRYSTAL except set TIME BASE on OSCILLATOR rear panel to INT TIME BASE Initial conditions and settings REFERENCE Connect high impedance in DECODER put of frequency counter to test point U14 pin 12 Internal Reference Perform ance Tests seg Section IV check good _ 1 MHz from U12A is as shown in Table 8 7 See Table 8 6 fb 8 6 for Band Codes Check Ui and associated circuitry division Check U13 U14 preset decoder RANGE switch and associated circuitry Connect counter to test point B U5 pin 6 Set RANGE and COUNTER MODE switches as shown in Table 8 6 1 division 15 as shown in able 8 6 Check U15 preset decoder RANGE switch and asso ciated cireuilry EXPAND Initia conditions and settings DECODER Connect high impedance input of frequency counter to test point C ULT pin 11 7 812 5 Hz i e division by one Check U16 U17 and associated circuitry Set COUNTER MODE EX PAND to X10 Set COUNTER MODE EX PAND to X100 LOCK DECODER
441. e A7R28 to 0757 0465 RESISTOR FXD 100K 1 0 125W F TC O 100 Change A7R45 to 0698 3159 RESISTOR FXD 26 1K 1 0 125W F TC 0 t100 NOTE For instruments with serial prefixes below 1552A the recommended replacement for A7R28 is 0757 0465 and for A7R45 is 0698 3159 For instruments not already modified as above it will be necassary to replace both A7R28 and A7R45 the first time either resistor is replaced through 6 15 Table 6 3 Change A8A2C4 to 0180 0374 CAPACITOR FXD 10UF 10 20WVDC Change A8A2CI2 to 0160 2207 CAPACITOR 900PF 5 900WVDC Add A8A2C32 0180 0374 CAPACITOR 10UF 10 20NVDC Add A8A2C33 0160 03877 CAPACITOR FXD 100PF 20 200WVDC CEIL Change 8 2 17 0698 7277 RESISTOR 51 IK 2 0 05W TC O 100 Change A8A2R19 0698 7270 RESISTOR FXD 26 1K 2 0 05W TC O 100 Delete A8A2R68 Add A8A2R59 0698 7281 RESISTOR FXD 75K 2 0 05W F TC Ox100 Add A8A2R60 0698 7188 RESISTOR FXD 10 2 0 05W F TC Ox100 Add A8A2R61 0698 7243 RESISTOR FXD 1 96K 296 0 06W F 1 Add A8A2R62 0698 00 Change A8A2U20 24 and U28 and1820 1684 NOTE In instruments with serial prefixed below 1552A the recommended replacement for A8A2U20 24 and U28 is 1820 1684 If not already present C33 must be added when these parts are installed Service Sheet 6 Schematic Add a resistor A5R42 from A5TP4 to ground with a nominal value of 19 6k Ohms Service Sheet 7 Schematic Change A7R28 to 100K Ch
442. e Q output of U2A to go high and the Q output of U2B to go low When the clock is low the output of OR gate USA is low When the clock goes high the Q output of U2A goes low the Q output of U2B remains low and the output of OR gate U5A goes high When the clock goes low the output of OR gate again goes low When the clock goes high the Q output of U2B goes high as does the output ot OR gate and remains high until the next time base termination The T input of U2 received two pulses which shifted the output register up twice after being cleared and loaded with the preset inputs TROUBLESHOOTING It is assumed that a problem has been isolated to the counter time base as a result of using the Model 0408 Option 004 iroubleshooting block diagrams Troubleshoot by using the test equipment listed below performing ihe initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital Voltmeter HP 3480D 3484A Osciloscope HP 180A 1801A 1820C Frequency Counter HP 5327C Initia Test Conditions Top cover removed see Service Sheet G for removal procedure A8 Counter Lock Assembly casting cover removed Counter Lock Board Assembly removed and extended for service with access to Time Base Assembly see Service Sheet C for procedures Initial Control Settings COUNTER MODE EXPAND Off LOCK Off Sourc
443. e capacitive loading of the cavity The oscillator drives two output amplifiers The Fre quency Counter Buffer Amplifier drives the fre quency counter the Divider Filter Buffer Ampli fier drives the dividers which drive the amplitude modulating and leveling circuits The oscillator s cavity has two varactor diodes that allow the capacitive loading to be varied by voltages at the anode and cathode to provide FM and phase lock FM Circuits Service Sheets 6 7 and 8 The RF oscillator s varactor cathode is driven by the FM Amplifier which provides accurate ampli fication or attenuation of the modulation signal and shapes the signal to compensate for the non linear characteristics of the varactor diodes Separate shaping circuits are used for positive and negative voltage excursions The PEAK DEVIA TION switch which controls basic FM amplifier gain is mechanically linked to the RANGE switch since for a given amount of peak deviation the percent deviation i e the amount of deviation relative to the carrier frequency changes as the frequency range is changed Also as the frequency is tuned the FM deviation changes An FM Gain Compensation circuit with a potentiometer which is geared to the FREQUENCY TUNE control adjusts for the change in FM sensitivity with tuning Inputs to the FM circuits are routed through the FM stitch In the CAL position an accurate 1 Vdc is applied to the FM input External inputs are applied in A
444. e g with the Model 141T 8552B 8554B increase two steps clockwise Adjust the DET ADJ potentiometer A26A1R19 to give the reading of step 6 1 mVdc 8 Repeat steps 5 to 7 until the readings of steps 6 and 7 are the same within 1 mVdc 9 Perform Output Level Vernier and Meter Adjustment 5 30 and Preliminary AM Adjustments 5 31 5 30 OUTPUT LEVEL VERNIER AND METER ADJUSTMENT REFERENCE Service Sheets 12 and 16 DESCRIPTION The RF level accuracy for the upper OUTPUT LEVEL attenuator ranges is measured with a power meter and the generator s output level and panel meter are adjusted at 13 dBm For the lower ranges a reference signal is established on a spectrum analyzer display the Signal Generator s OUTPUT LEVEL switch and the spectrum analyzer s vertical scale log reference level control are stepped together and any amplitude variations at 67 and 97 dBm are measured on the analyzer s display An RF attenuator and amplifier at the RF OUTPUT are adjusted for analyzer compatibility and best sensitivity This procedure uses an IF substitution technique in which the spectrum analyzer s IF is the standard the IF step accuracy should be within 0 2 dB overall The IF step accuracy can be checked using the above technique by comparing a lab calibrated attenuator such as HP Model 355D Option H36 with the IF step control at the frequency of attenuator calibration e g 3 MHz for the HP 355D Option H36 5 14 Model 8640B Option
445. e switch operation k Reinstall covers LEAD MOVED TO HERE _7 958 REMOVED FROM HERE Figure 7 9 Modified Line Switch Wiring Model 8640B Option 004 7 33 Reduction in Popcorn Noise on Power Supplies Serial Number Prefixes 1406A and Below 7 34 Excessive popcorn noise i e random vol tage shifts on the order of 1 mV can be reduced by changing the IC regulator 1801 2001 and U2 A22U1 and U2 to HP 1826 0177 The noise can cause random shifts in frequency of the RF oscillator which is particularly sensitive to noise on the 20 V supplies After mofication perform the Power Supply Adjustments Section V 7 35 Recommended Fuse Replacement for 220 240V Operation refixes 1423A and Serial Number 7 36 The recommended replacement for the power line fuse F1 to 220 or 240V operation is 1 25A normal blow HP Part Number 2110 0094 The higher current rating will prevent occasional blowing of the fuse at turn on 7 37 To show the new fuse rating on the line power module an adhesive backed label is available 4 HP Part Number is 7120 4264 Model 8640B Option 004 Manual Changes 7 38 The manual changes given below are for correcting errors and for adapting tbe manual to instruments containing improvements made after the printing of the manual Make all ERRATA corrections first and then make all appropriate serial number related changes indicated in the table Serial Prefix or Number Make Manual C
446. e test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital HP 3480D 3484A Oscilloscope cess Rede HP 180A 1801A 1820C Frequency Counter e 5327 Meter Circuits A2 A4 SERVICE SHEET 17 Service SERVICE SHEET 18 Cont d Initial Test Conditions Top cover removed see Service Sheet G for removal procedure A8 Counter Lock Assembly casting cover removed with access to 8 RF Scaler Assembly and A8A3 Time Base Assembly see Service Sheet C for procedures Connect RF OUT to COUNTER INPUT Initial Control Settings Model 8640B Option 004 COUNTER MODE EXPAND Off LOCK Off Source EXT 0 10 JANE do A a OFF FM OFF RANGE 4 8 MHz FREQUENCY TUNE Fully CW OUTPUT EEVEL 22 22 100 mVOLTS OUTPUT LEVEL Vernier CAL RF ON OFF ON Counter RF Scaler Troubleshooting Test Conditions and Control Settings Component or Circuit RF SCALER 8 1 Initial conditions and settings Check fre quency at COUNTER INPUT jack and at U3B pin 6 Set RANGE to 32 64 MHz and COUNTER MODE to EXT 0 550 Check frequency at COUNTER INPUT jack and at U3B pin 6 Initial conditions and settings except set COUNTER MODE to INT RANGE to 256
447. e the spectrum analyzer to peak the trace NOTE Throughout this test check that the signal is peaked in the center of the analyzer s passband Set the digital voltmeter to read mVdc with maximum filtering Adjust the spectrum analyzer s vertical sensitivity for a digital voltmeter reading of 200 0 mVdc Set calibrated step attenuator to O dB and note the digital voltmeter reading Digital Voltmeter reading mVdc Set calibrated step attenuator to 20 dB and note the digital voltmeter reading Digital Voltmeter reading mVdc Perform steps a b and c to obtain a value of offset voltage to be used in step 12 a steps 6 and 7 derive values of a expressed as a ratio from the formula a 104 where A Attenuation dB 20 and where Attenuation is the attenuation of step 3 minus that of step 6 or step 7 Atten uation figures should be obtained from the step attenuator s calibration chart which is accurate to 0 02 dB at 3 MHz e g a 3 16 410 dB for step 6 and a 0 31Q 10 dB for step 7 a step 6 a step 7 5 20 Model 8640B Option 004 Adjustments ADJUSTMENTS 5 32 AM ACCURACY ADJUSTMENT Cont d 10 11 12 13 14 15 16 b steps and 7 derive values of offset voltage V off from the formula mVdc 200 a Voff a where mVdc is the digital voltmeter reading of step 6 or step 7 and where a is the value derived in step 8a Voff step 6 Voff step
448. e time so that last three digits span from 000 to 999 Hz Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 49 INTERNAL REFERENCE DRIFT RATE STABILITY TEST Cont d 4 10 11 Calibrate the recorder for a zero to full scale reading that corresponds to a 000 to 999 Hz reading of the frequency counter s last three digits To check drift rate as a function of time and line voltage now set counter so that it s using the quartz oscillator Set the counter s time base control for a 10s gate time NOTE The above procedure sets the counter s actual gate time to 100s because the reference being used is 1 MHz instead of the 10 MHz reference the counter normally uses This means that the counter s reading must be divided by 10 to find the actual frequency of the signal being measured i e the recorder s calibration is 0 00 to 9 99 Hz full scale Record the generator s internal reference frequency for one hour The frequency change in one hour should be lt 0 27 Hz lt 0 05 ppm 1 digit counter ambiguity Time 027 7 Any change in line voltage or chamber temperature could make the instrument s drift rate us time appear to be out of specification Set variable voltage transformer 5 above the nominal voltage set on generator s line power module e g if nominal line voltage is 120 Vat set transformer for 126 Vat Then note the frequency the counter s indication must be divided by 10
449. ea cd 0 5 1 MHz FREQUENCY TUNE 9 5 MHZ OUTPUT LEVEL Switches 10 dBm OUTPUT LEVEL Vernier RF ON OFF LON 2 Set spectrum analyzer to measure harmonics 35 dB below the fundamental from 0 5 to 2 MHz Set input attenuation to 50 dB resolution bandwidth to 100 kHz frequency span per division scan width to 1 MHZ scale to log 10 dB div and scale reference level to 10 dBm Adjust analyzer s frequency controls to set O Hz to the left edge of the display NOTE If 50 dB of analyzer input attenuation is not available use an external attenuator such as the Model 355D 3 Slowly tune Signal Generator to 1 MHz checking that all harmonics are more than 35 dB below the fundamental 35 dB NOTE If any harmonic below 512 MHz appears to be out of specification remove any possible analyzer error and remeasure the harmonic as follows a Tune the generator to the frequency of the harmonic b Using the analyzer s IF attenuator step the signal down 30 dB on the display and note the 30 dB point on the display c Step the IF attenuator up 30 dB and retune the generator to its original setting d Using the 30 dB point noted on the display as a reference remeasure the harmonic 4 22 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 19 HARMONICS TEST Cont d 4 Set spectrum analyzer and Signal Generator as shown be
450. eet 20 component locations Replace Figure 8 66 with attached figure 7 33 Model 8640B Option 004 08640 90073 CHANGE 6 Cont d P O A8A2 Counter Lock Board Assembly Component Locations P O Change 6 Service Sheet 20 schematic Change part number of A8A2 subassembly to 08640 60258 Replace appropriate portion of schematic with attached partial schematic P O Figure 8 67 7 34 Model 8640B Option 004 08640 90073 CHANGE 6 Cont d w 1820 0328 1 2 P O Figure 8 67 Up Down Counter and Display Schematic Diagram P O Change 6 7 35 Model 8640B Option 004 08640 90073 CHANGE 6 Cont d Service Sheet 21 component locations Replac _Figure 8 68 with attached figure P O A8A2 Figure 8 68 P O A8A2 Counter Lock Board Assembly Component Locations P O Change 6 Service Sheet 21 schematic Change part number of A8A2 subassembly to 08640 60258 Replace appropriate portion of schematic with attached partial schematic P O Figure 8 69 P O Figure 8 69 Counter Phase Lock Schematic Diagram P O Change 6 7 36 Model 8640B Option 004 08640 90073 CHANGE 7 paragraph 5 21 Change paragraph c to read as follows C A9A1A2C6 C7 and C8 If the A9A1A2 FM Gain Switch Board Assembly has been replaced or repaired measure the 3 dB bandwidth at A7TP3 with an oscilloscope on the following RF frequency ranges while driving the FM INPUT connector with an external te
451. eing used has recently been measured and noted skip step 4 and go to step 5 and eliminate the calibrated step attenuator from the test setup 4 Measure analyzer s dc offset Voff by performing steps through f a Set generator s controls as follows Meter Function LEVEL AM OFF RANGE ex 2 4 MHz FREQUENCY TUNE 3MHz Set analyzer s center frequency controls to 3 MHz Adjust analyzer s reference level controls for 500 mVdc indicated on DVM 1 Set step attenuator to 20 dB Note DVM reading VDET 2 Calculate V ff where V DET 2 a VDET 1 Voff l a and VRF2 VRFI i e attenuation for 20 dB it is 0 1 therefore 2 50 mVdc Voff 09 Reset step attenuator O dB Signal Generator as specified in step 1 and spectrum analyzer as specified in step 3 5 To Calibrate the spectrum analyzer for the percent AM measurement use the analyzer s reference level controls to set 282 8 mV at vertical output as measured on the DVM For example if Voff is 50 0 mV then set 282 8 mV 50 0 mV or 232 8 mV at vertical output Check that trace is peaked on analyzer display 6 To measure modulation percent set DVM to measure mVrms ac only The DVM should read 180 mVrms 5 Check that trace is peaked on analyzer display 171 0 189 0 mVrms 4 61 Perform
452. el meter 3 dB reading on meter Set OUTPUT LEVEL switches for a 17 dBm reading on power meter Disconnect power meter from generator and connect step attenuator amplifier and spectrum analyzer to RF OUT Set step attenuator to 30 dB Set spectrum analyzer s center frequency controls to 50 MHz stabilizer on resolution bandwidth to 10 kHz frequency span per division scan width to 5 kHz input attenuation to 0 dB display smoothing video filter to 100 Hz and log linear display switch to 2 dB log Set the reference level switch for a 10 dBm reference level at the top graticule line on the display adjust the reference level vernier to place the signal to the display s fifth horizontal graticule line Set generators OUTPUT LEVEL to 47 dBm Set analyzer s reference level switch to 40 dBm and note signal level on display i e the difference between the signal level and the fifth horizontal Set step attenuator to 0 dB reset analyzer s reference level switch to 10 dBm and adjust analyzer s reference level vernier for the same signal level noted in step 7 Set generators OUTPUT LEVEL to 67 dBm set analyzer s reference level switch to 30 dBm and adjust generators OUTPUT LEVEL Vernier to set signal on analyzer s display to the fifth horizontal graticule line to the same place it was set in step 6 Adjust the 10 uV adjustment 19 2 7 for a 67 dBm indication on generator s panel meter 3 dB reading on meter Set g
453. eliminary FM Adjustments Test omit meter check 5 40 4 45 FM Linearity Adjustment 5 41 or 5 42 FM Sensitivity Adjustment 5 43 5 4 Model 8640B Option 004 Adjustments Table 5 2 Post Repair Tests and Adjustments 2 of 4 Assembly Repaired Performance Tests Adjustments 8 Counter Lock Assy A9 Peak Deviation and Range Switch Assy 10 Divider Filter Assy Operator s Check Figure 3 5 Frequency Accuracy and Fine Tune Test accuracy only 4 14 Frequency Stability Tests 4 15 4 16 4 17 and 4 18 Sub Harmonics and Non Harmonic Spurious Test 4 20 Output Leakage Test 4 31 Counter External Sensitivity Test 4 47 Internal Reference Accuracy Test 4 48 Internal Reference Drift Rate Stability Test 4 49 Phase Lock Restabilization Time Test 4 50 Operator s Check Figure 3 5 FM Sensitivity and Accuracy Test 4 45 Frequency Range Test 4 13 Harmonics Test 4 19 Output Level Flatness Test 4 27 Output Leakage Test 4 31 Check power supply voltages 5 25 Internal Reference Frequency Adjustment if necessary 5 44 Check power supply voltages 5 25 Peak Deviation and Range Switch Adjustment if necessary 5 33 Range Switch Adjustment 5 34 preliminary FM Adjustments if necessary 5 40 FM Linearity Adjustment if necessary 5 41 or 5 42 FM Sensitivity Adjustment if necessary 5 43 Check power supply voltages 5 25 Range Switch Adjus
454. ematic Remove A7 Assembly from chassis Check com ponent resistances with DVM Voltages check good If Indication Normal Indication is Abnormal Components check good Replace faulty compon ent Check counter phase lock circuits and U1 Components check good Replace faulty compon ent Model 8640B Option 004 Figure 8 28 P O A7 FM Shaping Assembly Component Locations 2 Wl i 809 357 3 C8 e 8 SHAPE PIO 13 GUERRE PHASE LOCK LOOP FILTER 20V 1 R2 350 5 3 ji R7 42 2K 405v 215 cl PHASE LOCK IN 19 1 0 2yF 0 22 uF Ul 20V l 6 Service NEG REFERENCE DESIGNATIONS WITHIN OUTLINED ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN Q4 R ug 1853 0020 CLUDES ASSEMBLY NUMBER e g OF ASSEMBLY Al FM ENABLE sm 2000 15 AIRI DESIGNATIONS OF OTHER COMPONENTS ARE PIO A9 PEAK DEVIATION AND RANGE SWITCH ASSY 08640 60117 __ P O FM SHAPING ASSY PIO AL REFERENCE DESIGNATIONS FM SYSTEM E MODULATION GAIN umm NEGATIVE SHAPING eS METERING nc 5 MOTHER nu 8 SEN BOARD ASSY R55 08640 60057 PEAK DEVIATION R43 100 a ANNUNCIATOR veviation I 60 PNE N 1 1854 i i DIFFERENTIAL enda 1854 0071 GEARING E d R56 DELETE
455. emoving cursor disc and gear gently slide it off the shaft to avoid damage to the disc 3 Remove pan head screw with washer and lockwasher that secures All Assembly to A13 Mother Board Assembly The screw is accessible from top of instrument 4 Remove All Assembly by gently lifting the board extractor at rear of board and sliding assembly to rear and out of chassis 5 To connect Al 1 Assembly for service place assembly on extender board and install in chassis Reinstall cursor disc and gear MOD ULATION FREQUENCY knob and vernier knob 400 Hz position of knob should be toward top of instrument Al 1 Reinstallation 6 Reinstall All Assembly by reversing the pro cedures in steps one through four or five NOTE Check variable frequency accuracy to assure that the vernier disc is in the proper position Model 8640B Option 004 Reference Jis MER AU NBG WwW NBEO Service A9 Peak Deviation and Range Switch Assembly Legend A11 Variable Frequency Modulation Oscillator A9MP1 A9MP2 P O A9MP8 A9MP3 A9MP4 A9MP5 A9R1 A9MP6 A9MP7 A9MP8 P O A9MP8 9 A9MP10 Assembly Option 001 Legend Reference Description Designator P 11 151 Rotary Switch 11 1 1 Gear Support Housing 11 1 2 Spur Gear 11 1 Spur Gear A11MP3 Spur Gear 11 4 Audio Oscillator Cover Capacitor A11C1 Variable Capacitor P O All Audio Oscill
456. en reset the controls to the settings should be carried out only by a skilled specified in the box on the right hand side person who is aware of the hazard involved NOTE The last two foldouts in the manual have Capacitors inside the instrument may top and bottom internal views of the in still be charged even if the instrument PHASE LOCK strument that show the locations of the has been disconnected from its source CIRCUITS test points assemblies and cables all RF of supply cables are accessible from the bottom of Make sure that only fuses with the required rated current of the spec The blocks on Service Sheet 3 are keyed by the req FM CIRCUITS AND RF OSCILLATOR ified type normal blow time delay numbers located in their lower right hand corners t df t Th to the Service Sheets that have the circuit sche Sto y are reach replacement The Uee AMIAGC CIRCUITS AND OUTPUT AMPLIFIER he si h of repaired fuses and the short circuiting 1V T CAL bo matics In our example suppose the signals to the of fuseholders must be avoided M RANGE AUX RF 1 A26A3 Assembly are correct and the signals from DC nmm Q Frequency TUNE UTER 1 OUTPUT A26A3 are incorrect Turn to Service Sheet 12 x DEVIATION SWITCH RF 4 A LEVEL Q OUTPUT RET and isolate the trouble to a component or replace
457. ence frequency set FM switch to AC then again note reference frequency Except for the 1 digit count ambiguity it should not have changed ModeChange vV No Change 4 50 PHASE LOCK RESTABILIZATION TIME TEST SPECIFICATION Restabilization Time phase locked mode after frequency change after band change or after 1 min in RF OFF Mode lt 1 min after relocking to be within 0 1 ppm of steady state frequency DESCRIPTION A frequency counter digital to analog converter and strip chart recorder are used to measure stability after relocking See Table 4 1 Recommended Test Abridgements NOTE For these tests ambient room temperature and line voltage should not change EQUIPMENT Frequency Counter HP 5327C Option 003 Digital to Analog Converter HP 581A Option 002 Recorder for D A Converter HP 680 PROCEDURE l Connect equipment as shown ih Figure 4 1 after setting Signal Generator s controls as follows COUNTER MODE EXPAND Off LOCK Off Source NT FM OFF RANGE 32 64MHz FREQUENCY TUNE 50 MHz RF ON OFF This specification applies only if the RF ON OFF switch has he en wired to turn the RF Oscillator off 4 92 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 50 PHA
458. enerators OUTPUT LEVEL to 97 dBm Set analyzer s reference level control to 60 dBm Adjust OUTPUT LEVEL Vernier to set signal on analyzer s display to the fifth horizontal graticule line to the same place it was set in step 6 Adjust the 1 uV adjustment A19A2RS for a 97 dBm indication on generator s panel meter 3 dB reading on meter Perform Preliminary AM Adjustment 5 31 and AM Accuracy Adjustment 5 32 if repairs have been made to the A26 AM AGC and RF Amplifier Assembly Model 8640B Option 004 Adjustments ADJUSTMENTS 5 31 PRELIMINARY AM ADJUSTMENTS REFERENCE Service Sheets 13 14 and 15 DESCRIPTION The following adjustments are performed 1 dc offset voltages of demodulation amplifiers are adjusted 2 The ac gain of the AM offset amplifier is adjusted 3 The ac and dc gains of the demodulation output amplifier are adjusted TEST OSCILLATOR DIGITAL VOLTMETER OUTPUT GROUND CLIP A26ABTP1 2 r 74 26 3 stea 1 A2GAZTP3 7 1 26 2 1 MODEL 86408 Croc OPTION 004 INPUT 95797 mE La su Figure 5 3 Preliminary AM Adjustments EQUIPMENT Digital Voltmeter HP 3480D 3484A Option 043 Test Oscillator 204D PROCEDURE
459. er FRAGILE to assure careful handling In any correspondence refer to the instrument by model number and full serial number 2 27 Other Packaging The following general in structions should be used for re packaging with commercially available materials a Wrap the instrument in heavy paper or plastic If shipping to a Hewlett Packard office or service center attach a tag indicating the type of service required return address model number and full serial number b Use a strong shipping container A dou blewall carton made of 350 pound test material is adequate 2 3 Installation c Use enough shock absorbing material 3 to 4 inch layer around all sides of the instrument to provide a firm cushion and prevent movement inside the container Protect the control panel with cardboard TILT STAND BOTTOM COVER Model 8640B Option 004 d Seal the shipping container securely e Mark the shipping container FRAGILE to assure careful handling FOOT RELEASE BUTTON LARGER NOTCH 10 FILLER STRIP TRIM STRIP ADHESIVE BACKED INSTRUCTIONS 1 REMOVE TILT STAND PLASTIC FEET AND TRIM STRIPS 2 ATTACH FILLER STRIP AND RACK MOUNTING FLANGES KEEPING LARGE NOTCH ON FLANGES TO INSTRUMENT BOTTOM Figure 2 3 Preparation for Rack Mounting SECTION III OPERATION 3 1 INTRODUCTION 3 2 This section describes the functions of the controls and indicators of the Model 8640B Option 004 Signal Generator
460. er Amplifier and AGC Det ctor Assembly Component Locations 8 48 P O A26A2 AM Offset and Pulse Switching Assembly Component Locations Amplifier Pulse Switching and Step Attenuator Schematic Diagram 8 50 P O A26A2 AM Offset and Pulse Switching Assembly Component Locations 8 4 8 51 AM Preamplifier Schematic Diagram 8 4 8 52 A26A8 Demodulation Amplifier Assembly Component Locations 8 49 i i eS 1 P Si IA n lt Table of Contents Model 8640B Option 004 ILLUSTRATIONS cont d Figure Page AM Interconnections RF ON OFF Switch and Demodulation Amplifier Schematic Diagram 2 18 49 8 54 A19A2 RF Vernier Assebly component Locations Bed 8 51 8 55 JRF Vernier Schematic Diagram 8 51 8 56 A2 Meter Switch Detector Assembly Component Locations 8 57 A4 Metir Annunciator Drive Aseni Component Locations 8 58 P 0 Annunciator Assembly Component Locations I 8 59 Meter Circuits Schematic Diagram 8 60 A8A1 RF Scaler Assembly Component locations P O A8A3 Time Base Assembly Component Locations 8 55 8 62 Counter RF Scaler Schematic Diagram 8 55 8 63 P O A8A3 Time Base Assembly Component Locations 8 64 Counter Time Base Schematic Diagram 8 65 8 4 Counter Display Assembly Component locations P O 8 8 66 P O A8A2 Counter Lock Board Assembly Component Locations 8 67 Up Down Counter and Display
461. er scale lamp The meter has three linear scales 0 5 0 10 and 0 3 or actually 0 3 16 with three lamps to indicate the appropriate scale The lamps are located on the A6 Annunciator Assembly The meter also has a log scale calibrated in dBm 5082 for use in the LEVEL meter mode Positive Peak Detector A2 The Positive Peak Detector samples the ac peak of the incoming signa and stores the voltage on capacitor C5 The AM or FM input signals are ac coupled into Buffer Amplifier U1 by capacitor C1 and resistor R4 U1 is internally connected as a voltage follower Resistor R3 provides input bias current for U1 and presents a constant load impedance to the inputs Amplifier U2 is a voltage comparator When the input voltage at pin 4 exceeds the voltage at pin 3 the output rapidly switches to a level equal to the voltage across C5 which is also connected to pin 3 plus the voltage drop across the forward biased diode CR1 The amplifier charges C5 until the voltage at pin 4 equals the voltage at pin 3 and maintains this condition until the voltage at pin 4 drops The amplifier output then swings to a maximum negative value about 8V CR1 reverse biases and C5 slowly discharges until the voltage at pin 4 again exceeds that at pin 3 Thus the positive peak value of the input voltage is stored on Cb Resistors R7 and discharge C5 whenever the input signal level is reduced slightly between input peaks Resistor R11 adds a small amount of
462. er to 200 Adjust 11 2 and C3 until voltage level at is within 0 01 Vrms of level recorded in step 8 and frequency is 20 0 0 1 kHz Set MODULATION FREQUENCY vernier to 20 The counter should read 2 00 0 01 kHz and voltage level at A11TP4 should be within 0 01 Vrms of level recorded in step 8 Repeat steps 8 and 9 until voltage level and frequent y are correct Monitor voltage at Al 1TP4 while using MODULATION FREQUENCY switch and vernier to tune oscillator from 2 kHz to 20 kHz The voltage level at 2 kHz on the X100 range should be 1 6 0 05 Vrms and level at all other frequencies should be within 0 03 Vrms of level at 2 kHz At 2 kHz 1 55 1 65 Vrms All frequencies 0 03 Vrms 5 10 Model 8640B option 004 Adjustments ADJUSTMENTS 5 27 VARIABLE FREQUENCY MODULATION OSCILLATOR ADJUSTMENT OPTION 001 Cont d 12 If level at A11TP4 is too high reduce AIIR28 by one standard value 10 if level is too low increase 11 28 by one standard value Then repeat steps 8 through 11 13 Set MODULATION FREQUENCY range switch to X3 K and vernier to 200 and adjust HIGH FREQ capacitor Al1C9 for a counter reading of 600 3 kHz 597___ 603 kHz 14 Connect DVM to AM OUT test point 5 Set MODULATION FREQUENCY range switch to 100 and the vernier to 20 Adjust AM FM adjustment A11R35 for 840 10 mVrrns at 5 830 850 mVrms 15 Connect DVM to the FM OUT test point AIITP3 It should read within 5
463. erence graticule line on analyzer s display represents 110 dB Hz below carrier level the transfer from a 1 kHz BW to a 1 Hz BW is 30 dB The average noise level on the display should be gt 12 dB below top graticule line at 20 kHz i e gt 122 dB below carrier 12 dB NOTE Set oscilloscope to check for possible line related signals in test setup They should be 10 m Vp p 7 Set test Signal Generator to 450 MHz and FM switch to OFF Set reference signal generator to 449 98 MHz i e 20 kHz below the test generator s frequency Repeat steps 2 through 6 The average noise level on the display should be gt 20 dB below top graticule line at 20 kHz 20 dB NOTE SSB phase noise can be checked at any other frequency from 230 kHz to 550 MHz by following the procedures given above Noise decreases approximately 6 dB per each octave band change down to 130 dB below carrier 4 22 SINGLE SIDEBAND BROADBAND NOISE FLOOR TEST SPECIFICATION SSB Broadband Noise Floor at greater than 1 MHz offset from carrier averaged rms noise level below carrier stated in a 1 Hz bandwidth 2130 dB down ISee Hewlett Padmrd Application Note 160 4 Spectrum Analysis Noise Measurement 4 27 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS irre 4 22 SINGLE SIDEBAND BROADBAND NOISE FLOOR TEST Cont d DESCRIPTION A spectrum analyzer is used to measure the broadband noise floor a reference signal generator and
464. ers and Amplitude Modulator Troubleshooting Test Conditions and Control Settings Normal Indication If Indication is Abnormal SUMMING AMPLIFIER A26A4 Initial conditions and set tings Set AGC switch 51 to AGC off position 1 2 Vp p sine wave 1 kHz at TP6 CQ3 Check QI Q2 Q3 and associated circuitry MODULATOR DRIVER AMPLIFIER A26A4 Initial conditions and set tings Set AGC switch S1 to AGC off position 4 8 Vp p modified square wave 1 kHz at TP7 DRVR 16 Vp p modified square wave 1 kHz at TP8 MOD Check Q4 U4A U4C and associated circuitry Check Q5 Q6 Q7 and associated circuitry Set RANGE to 4 8 MHz 16 Vp p modified square wave 1 kHz at TP8 MOD Set RANGE to 1 2 MHz 16 Vp p modified square wave 1 kHz at TP8 MOD Check U3A U3D U4B U4D and associated circuitry Check U3B U3C U4E U4F and associated circuitry MODULATOR PREAMPLIFIER A26U2 initial conditions and set tings AGC switch A26UASI set to AGC on position gt 5 dBm gt 125 mVrms into 50S1 at AUX RF OUT jack on rear panel Check U2 and associated circuitry METER AMPLIFIER A26A4 Initial conditions and set tings Panel meter indicates 10 dBm 707 rnV Check U1A and associated circuitry MODULATION OVERLOAD DETECTOR A26A4 PULSE OVERLOAD DETECTOR A26A4 Initial conditions and set tings except set OUT PUT LE
465. es 20 Hz to 10 MHz 4 48 INTERNAL REFERENCE ACCURACY TEST SPECIFICATION Accuracy after calibration at 25 C and 2 hour warm up Better than 1 ppm for 15 to 35 C Better than 3 ppm for O to 55 C DESCRIPTION A frequency counter is used to measure the Signal Generator s counter accuracy A temperature controlled chamber is used to set the temperature FREQUENCY COUNTER TEMPERATURE CONTROLLED CHAMBER INPUT 1 0 MODEL 86408 TIME BASE REAR PANEL OPTION 004 0 99 Figure 4 33 Internal Reference Accuracy Test Setup EQUIPMENT Frequency Counter 5327C Option H49 Temperature Controlled Chaamber Statham Model 325 PROCEDURE l Connect equipment as shown in Figure 4 33 Check that TIME BASE REF INT EXT switch on the rear panel is set to INT 4 88 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 48 INTERNAL REFERENCE ACCURACY TEST Cont d 2 Set chamber for various temperatures between 15 and 35 C At each temperature allow generator to stabilize for two hours then measure the frequency It should be 5 MHz 5 Hz 4 999 995__ 7 5 000 005 Hz 3 Set the chamber for various temperatures between O and 55 C Again allow the generator to stabilize for two hours at each temperature and measure the frequency It should be 5 MHz 15 Hz 4 299 485 7 5 000 115 Hz 4 49 INTERNAL REFERENCE DRIFT RATE STABILITY TEST SPECIFIC
466. es while monitoring the output voltage meter Usually a problem will appear as shown in the following table Symptom Probable Cause No output on one band only No output on one band and all bands below that band Low power at highest end of bands 8 to 1024 MHz only Overly high harmonics at lowest end of bands 8 to 1024 MHz only Intermittent power Changing bands does not change output frequency even though the counter may indicate a change The dividers and the Schmitt Trigger circuits are shown and discussed on Service Sheet 11 the relays driven by the Schmitt Defective output circuit for one of the dividers a filter or a slide switch Defective divider or 16 32 MHz low band filter or 0 5 to 8 MHz divider output transformer Defective geometric mean switching high band filters not being switched in Defective geometric mean switching low band filters not being switched in Poor contact on slide switch Loose coupler between RANGE switch and Divider Filter switch assembly Trigger circuits are shown on this service sheet NOTE The following procedure checks gross failure A more comprehensive check can be made by per forming the Filter Adjustment Section V Variable Frequency Modulation Oscillator for Option 001 A11 A13 SERVICE SHEET 9A Service SERVICE SHEET 10 Cont d Component or Circuit HIGH LOW BAND RELAYS A10A1 Test Conditions and Control Settings
467. essories required in the adjustment procedures In addition the tables contain the required minimum specifications and a suggested manufacturer s model number 5 11 Posidriv Screwdrivers 5 12 Many screws in the instrument appear to be Phillips but are not To avoid damage to the screw slots Posidriv screwdrivers should be used 5 13 Blade Tuning Tools 5 14 For adjustments requiring a non metallic metal blade tuning tool use the J F D Model No 5284 HP 8710 1010 In situations not requiring non metallic tuning tools an ordinary small screw driver or other suitable tool is sufficient No matter what tool is used never try to force any adjust ment control in the generator This is especially critical when tuning variable slug tuned inductors and variable capacitors 5 15 Service Aids 5 16 Miscellaneous Hardware Kit The HP 08640 60095 Miscellaneous Hardware Kit contains mechanical spare parts for the generator such things as nuts bolts screws and washers 5 17 Extender Board An extender board is sup plied with the generator that can be used to extend all circuit plug in boards except the 10 2 RF Divider Assembly and the 12 Rectifier Assem bly The RF Divider Assembly is self extending just remove the riser board and insert the Divider Assembly into the riser s socket 5 18 Wrench A wrench is supplied with the generator One end fits the SMC connectors used on the generator s RF cables the
468. est generator directly to analyzer Set RANGE to 0 5 1 MHz FREQUENCY TUNE to 1 MHz FM to OFF and reset reference on analyzer s display Set FM to AC with modulating signal s amplitude set for a test generator panel meter reading of 5 and its frequency set to approximately 2 079 kHz Then tune the signal s frequency for the first carrier null The signal s frequency should be 2 079 kHz 10 1 871 2 287 kHz 4 84 Model 8640B Option 004 PERFORMANCE TESTS 4 46 INCIDENTAL AM TEST SPECIFICATION Incidental AM at 400 Hz and 1 kHz rates lt 0 5 AM for FM up to 1 8 maximum allowable deviation lt 1 AM for FM at maximum allowable deviation DESCRIPTION Performance Tests An audio signal is used to amplitude modulate the Signal Generator The resulting modulated RF is detected and used to calibrate an oscilloscope The generator is then frequency modulated and any incidental AM is measured with the oscilloscope See Table 4 1 Recommended Test Abridgements MODEL 86408 OPTION 004 LOLOL 9o DIRECT CONNECTION 7 NINE INCH CABLE 10 0 001 TEE x ADAPTER OSCILLOSCOPE HEO 40 dB 2 AMPLIFIER 15 kHz CN 9 LPF TEE verTicLe JO 9 2 INPUT OUTPUT INPUT 50Q LOAD Figure 4 31 Incidental AM Test Setup EQUIPMENT Crystal
469. f 5096 Set the analyzer scan trigger to rodeo The peak to peak amplitude on the display should span 3 6 to 4 4 divisions centered about the fourth graticule line The waveform should appear undistorted Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 12 BASIC FUNCTIONAL CHECKS Cent d 7 4 10 d Adjust MODULATION for a peak to peak amplitude spanning the second and sixth graticule lines Connect an ac voltmeter to DEMOD OUTPUT The voltmeter should read between and 0 525 Vrms if the internal AC DC switch is set to DC or between 2 37 and 2 63 Vrms if the switch is set to AC Connect a pulse generator to AM INPUT and set it for an output of into 500 1 kHz rate and 0 5 ms width Set analyzer resolution bandwidth to 100 kHz or greater and no display smoothing Set AM to OFF Check that the signal is peaked and at the fourth graticule line Set AM to PULSE The level of the flat part of the pulse should be between 3 5 and 4 5 divisions Set AM to OFF Adjust the analyzer to view the 108 MHz signal in the smallest resolution bandwidth and frequency span that is reasonable and set vertical scale to 10 dB log per division Step OUTPUT LEVEL down in 10 dB steps and check that the output signal decreases in 10 dB steps to the lowest observable level on the analyzer FM Check Refer to step 1 for initial control settings a Set FREQUENCY TUNE to 1 MHz and OUTPUT LEVEL to 37 dBm Locate the signal on the
470. for optional assemblies are totaled by assembly and not inte grated into the standard list 6 11 ORDERING INFORMATION 6 12 To order a part listed in the replaceable parts table note the Hewlett Packard numb er and then cross reference that part number to the National Stock NUmber in table 6 5 Then order through normal ordering channels 6 13 If the part number does not have a National Stock Number then order the part through normal ordering channels using the Hewlett Packard part number 6 14 SPARE PARTS KIT 6 15 Stocking spare parts for an instrument is often done to insure quick return to service after a malfunction occurs Hewlett Packard has a Spare Parts Kit available for this purpose The kit consists of selected replaceable assemblies and components for this instrument The contents of the kit and the Recommended Spares list are based on failure reports and repair data and parts support for one year A complimentary Recom mended Spares list for this instrument may be obtained on request and the Spare Parts Kit may be ordered through your nearest Hewlett Packard office 6 1 Replaceable Parts 6 16 ILLUSTRATED PARTS BREAKDOWNS 6 17 Illustrated Parts Breakdowns for the follow ing assemblies are given on the alphabetic foldout pages in this manual located after the numbered schematic foldouts Al Output Level 1 dB Assembly A3 RF Oscillator Assembly 8 Counter Lock Assembly A9 Peak
471. frequency directly 1 29 When using the expand modes it is possible for significant digits or the decimal points to be shifted off the display When this occurs an OVERFLOW light reminds the operator that the display is not showing the complete output fre quency 1 30 The built in counter can also be used to count external input signals from 1 Hz to 550 MHz and eliminates the need for a separate frequency counter in many measurement systems Input sensitivity is 100 mV into 50 Using the EX PAND buttons it is possible to achieve a resolution of 1 Hz in the 0 10 MHz EXTERNAL count mode or 100 Hz in the 0 550 MHz mode 1 31 Phase Lock Mode 1 32 Also included in the Signal Generator is a built in phase lock synchronizer that locks the RF output frequency to the crystal time base used in the counter In this locked mode output stability is better than 5 x 10 h while the spectral purity and FM capability of the unlocked mode are preserved For higher stability it is possible to lock to an externally applied 5 MHz standard Two Model 8640B s can also be locked to a common timebase reference for performing various two tone measurements 1 33 Phase locking the generator is simple just push the front panel LOCK button The generator is then locked to the frequency shown on the LED display If lock is broken for example by tuning 1 3 General Information to a new output frequency or during warmup there is an immedi
472. front panel trim strip Temporarily connect the RF cable W2 to the counter and install the FREQUENCY TUNE knob PROCEDURE 1 Set Signal Generator s controls as follows RANGE 0 5 1 MHz FINE TUNE Centered 2 Remove bottom cover 3 Switch LINE to ON and let instrument warm up for one hour 4 Check that Varactor Anode bias is 14 70 0 01 Vdc at A7TP2 5 Tune FREQUENCY TUNE fully ccw Compare the position of the stop ring teeth wit NOTE Notice how the teeth on the stop rings line up in a staircase at the end stops The stop pin and the adjustable stop ring determine the lower frequency limit The stop pin and forward most stop ring determine the high frequency limit however adjustment of this will also effect the low frequency limit ADJUSTABLE STOP RING STOP PIN SETS LOW FREQUENCY STOP STOP RINGS THESE TWO PARTS ARE FASTENED TOGETHER 2 a FRONT ADJUSTMENT COLLAR SETS BOTH LOW AND HIGH FREQUENCY STOPS ADJUST THIS FIRST FOR HIGH FREQUENCY STOP Figure 5 6 Location of RF Oscillator Stop Adjustments Shown in Maximum ccw Position Top View with Instrument Upside Down 6 Adjust FREQUENCY TUNE fully cw The frequency should read between 1 0752 and 1 0760 MHz If it does not note how far off the frequency is 7 Adjust FREQUENCY TUNE until first setscrew on front adjustment collar appears Loosen setscrew 5 26 Model 8640B Optio
473. gister U3 The data inputs for the different counter modes are shown in Table 8 9 Note that only one data input is low for each In the unexpanded counter mode both EXP 10 and EXP 100 are high the output of NAND gate U1D is low and the clear CLR SERVICE SHEET 19 input of D flip flop U2B is low Flip flop U2B clears and holds the Q output high which holds one input of OR gate U5A high The output of OR gate UDA remains high regardless of the state of the other input which is the clock output from U5B The T input of shift register U3 is held high At the termination of a time base period the output of U5C goes momentarily high This output is inverted by U8A and drives the clear CLR input of U3 The output of USC is also delayed by resistor capacitor network R13 and C25 and drives the load LD input of U3 At the termination of each time base period the shift register outputs Q Qp Qc and are first cleared i e all go low then with the data inputs The outputs drive the decimal point inputs of the LED display Table 8 9 Data Inputs of Decimal Point Shift Register Decimal Point Position COUNTER Data Inputs MODE 5 1 em 0 1s 2 4 15 16 32 32 04 64 128 128 256 256 512 412 1024 Poe re X OIL IL I I Zo m I ror oro IL T 5 Wc Il Dr mm r r du I IL IL IE IE GL IE E OM CO CO D
474. gnal to and from dividers Each slider has three detented positions Mechanical action of the RANGE switch is shown in Figure 8 38 SERVICE SHEET 10 Cent d CONTACTS ANN PRINTED CIRCUIT BOARD Figure 8 38 Action of RANGE Switch TROUBLESHOOTING It is assumed that a problem has been isolated to the RF Filter circuits as a result of using the troubleshooting block diagrams Troubleshoot by using the test equipment listed below perform ing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital HP 3480D 3484A Initial Test Conditions Top cover removed see Service Sheet G for removal procedure 10 Divider Filter Assembly casting cover removed A10A2 RF Divider Assembly removed and extended for service with access to 10 1 RF Filter Assembly see Service Sheet E for procedures Initial Control Settings Meter Function VOLTS COUNTER MODE EXPAND Off LOCK u ax x Sw Was off Source INT sss s s OFF FM OFF RANGE 2 256 512 MH 2 FREQUENCY TUNE 550 MHz OUTPUT LEVEL RF ON SERVICE SHEET 10 Cont d RF Filter Circuits The quickest way to isolate a divider filter problem is to use the front panel controls to set various frequencies and frequency rang
475. h is a voltage divider in which the amount of feedback is determined by the output of a peak detector The amount of feedback automatically adjusts to main tain oscillation at a constant amplitude The voltage divider consists of R4 R3 CR1 and CR2 Diodes CR1 and CR2 are in ac parallel and dc series The ac resistance is determined by the dc voltage across capacitor C5 At the peak of each output cycle VR2 and CR3 conduct and replenish the charge lost from C5 The ac voltage at the output of U1 is about 5 1 Vrms Buffer Amplifiers Al 1 Resistors R5 R6 and R7 lower the oscillator output voltage to 2 3 Vrms at TP5 Resistors R13 Model 8640B Option 004 and R14 lower the voltage to about 0 84 Vrms at TP3 and TP4 Transistor Q5 drives the FM PEAK DEVIATION vernier potentiometer Q4 drives the AM MODULATION potentiometer Q1 drives the AM OUTPUT port and Q2 drives the FM OUT PUT port Signal levels at the two ports are approximately 1 Vrms into 600fl TROUBLESHOOTING It is assumed that a problem has been isolated to the fixed frequency modulation oscillator as a result of using the troubleshooting block diagrams Troubleshoot by using the test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital Voltmeter HP 3480D 3484A Oscilloscope HP 180A 1801A 1820C Initial Test Conditions Top and bottom c
476. hanges Serial Prefix or Number 1440A ta 1538A 1542A 154 1501A 1544A 1506A 1513A 1545A 1515A 1 4 1552A 1606A 1 16 1519A 1 5 1607A 1 17 Make Manual Changes 1520A 6 1524A 1526A 1 7 1530A 1 8 1532A 1 9 1534A ERRATA Page 1 0 Delete RACK MOUNT KIT Page 1 6 Paragraph 1 65 Delete Rack Mounting Kit HP 5060 8740 Page 1 6 Paragraph 1 67 Delete entire paragraph Page 1 d Paragraph 1 69 Add l 69a A Rack Mounting Kit is available to install the instrument in a 19 inch rack Rack Mounting Kits may be obtained through your nearest Hewlett Packard Office by ordering HP Part Number 5060 8740 Model 8640B Option 004 08640 90073 ERRATA Cont d Page 2 1 Paragraph 2 20 Change the first sentence to read Rack Mounting Kits may be obtained through your nearest Hewlett Packard Office by ordering HP Part Number 5060 8740 Page 3 17 Figure 9 1 In step d change the first sentence to read as follows and with the additional note When using an external modulation signal for avionics VOR ILS testing set AM o to DC NOTE When using an external modulation signal for general purpose testing AM switch o may be set to DC or AC DC if modulation signal is less than 20 Hz or if minimum phase shift is required and 5 3 Add the following step h 1 7 A8A1R12 14 Selection If ASAIUI or U5 is replaced proceed as follows before reassembling the counter 1 Inspect
477. he button lights when ON e AM selects amplitude modulation and source OFF no AM INT AM by internal oscillator AC AM by external source through AM INPUT jack gt 20 Hz ac 4 lt 5 Vpk DC AM by external source through AM INPUT jack ac de lt 5 Vpk PULSE when selected with no modulation it disables the RF output a positive pulse at AM INPUT pulses on the RF Mechanical Meter Zero sets meter suspension so that meter indicates zero when power is removed from instrument and instrument is in normal operating position Figure 3 2 Front Panel Controls Indicators and Connectors 4 of 4 Operation Model 8640B Option 004 INTERNAL AC DC SWITCH A26 AM CASTING 26 851 INTERNAL VIEW AC OC SWITCH AC DC Switch An internal selector switch on the Demodulation Amplifier within the A26 AM casting selects either ac only at 0 5 Vrms or ac at 0 1 Vrms plus dc at the front panel DEMOD OUTPUT jack A choice of demodulated outputs ensures compatibility with both solid state and vacuum tube modulation sources Figure 8 3 Internal AC DC Switch 3 6 Model 8640B Option 004 Operation REAR PANEL FEATURES o AUX RF OUTPUT nominal 5 dBm auxiliary external reference such as another RF output 500 ohm source impedance Signal Model 8640B by using the TIME does not contain amplitude or pulse modulation BASE Reference jack and switch however it does contain FM On the 512 1024 MHz D
478. he collector current of Q6 causes a ZW drop across R16 which offsets the amplifier output by 2 Vdc and establishes the AGC reference Capacitors C5 C6 and C7 fre quency compensate the amplifier The amplifier output drives OUTPUT LEVEL vernier 1 1 Service Sheet 16 Model Option TROUBLESHOOTING It is assumed that a problem has been isolated to the preamplifier as a result of using the troubleshooting block diagrams Troubleshoot by using the test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital Voltmeter HP 3480D 3484A Oscilloscope 180A 1801A 1820C Initial Test Conditions Top cover removed see Service Sheet G for removal procedure A26 AM AGC and RF Ampli fier Assembly casting top cover removed and 2642 AM Offset and Pulse Switching Assembly extended for service see Service Sheet F for procedures Initial Control Settings Meter Function 20 2 2 5 525 MODULATION 100 MODULATION FREQUENCY 2 1000 Hz AM Preamplifier Troubleshooting Component Test Conditions and or Circuit Control Settings If Indication Normal Indication is Abnormal AM PREAMPLI Initial conditions and FIER settings 2 Vp p at TP1 AM IN Check input switching A26A2 4 Vp p and 2 Vdc Check Q1 Q6 and at
479. he generator s counter The difference in reading between the two counters should be 110 Hz 2 ppm last digit uncertainty of 10 Hz 110 Hz 4 Set COUNTER MODE EXPAND to X10 and LOCK to ON Allow one minute to acquire phase lock Increase the frequency counter resolution by 10 The difference in counter readings should be lt 100 Hz 2 ppm 100 Hz 5 Note frequency counter reading Turn TIME BASE VERN control ccw until it just leaves the detent position The frequency counter should now read gt 1 kHz gt 20 ppm higher than the reading noted above 1 kHz 6 Turn TIME BASE VERN fully ccw The frequency counter should now read gt 1 kHz gt 20 ppm lower than the reading first noted in step 5 1 kHz 7 Set TIME BASE VERN to CAL fully cw Set COUNTER MODE LOCK to Off 8 Set FINE TUNE fully cw Note frequency counter reading then set FINE TUNE fully The frequency counter should read gt 50 kHz 1000 ppm lower than the reading noted above 50 kHz 4 15 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 15 FREQUENCY STABILITY VS TIME AND RESTABILIZATION TIME TEST SPECIFICATION Stability vs Time after 2 hour warmup 10 ppm 10min normal mode Restabilization Time normal mode After frequency change 15 min After band change none After 1 min in RF OFF mode 10 min NOTE Stability specifications for phase lock mode are determined by counter time base reference See the internal
480. he restoration of unserviceable equipment to a like new condition in accordance with original manufac turing standards Rebuild is the highest degree of materiel maintenance applied to Army equipment The rebuild operation includes the act of returning to zero those age measurements hours miles etc considered in classify ing Army equipments components D 3 Column Entries a Column 1 Group Number Column 1 lists group numbers the purpose of which is to identfy components assemblies subassemblies and modules with the next higher assembly b Column 2 Component Assembly Column 2 con tains the noun names of components assemblies sub assemblies and modules for which maintenance 1s authorized c Column 3 Maintenance Functions Column 3 lists the functions to be performed on the item listed in column 2 When items are listed without maintenance functions it is solely for purpose of having the group numbers in the MAC and RPSTL coincide d Column 4 Maintenance Category Column 4 specifies by the listing of a work time figure in the ap propriate subcolumns s the lowest level of maintenance authorized to perform the function listed in column 3 This figure represents the active time required to perform that maintenance function at the indicated category of maintenance If the number or complexity of the tasks within the listed maintenance function vary at different maintenance categories appropriate work time figure
481. heck each display digit for proper lighting of the LED s Release X1OO EXPAND button Press LOCK button The displayed count should be steady and the display should not blink Rotate FINE TUNE one half turn cw The display should remain unchanged Rotate FINE TUNE one turn ccw The display should remain unchanged Rotate FREQUENCY TUNE one half turn Phase lock should break and the display should blink Release LOCK button set COUNTER MODE to EXT 0 10 RANGE to 0 5 1 MHz FRE QUENCY TUNE to fully ccw position FINE TUNE centered and OUTPUT LEVEL to 7 dBm Connect RF OUT to COUNTER INPUT Counter should read 0 450 MHz or less but not all Zeros Rotate FREQUENCY TUNE to fully cw position Counter should read 1 07 MHz or greater Set counter reading to 0 625 MHz Set RANGE as indicated below and note frequency displayed for both EXT 0 10 and INT COUNTER MODE The frequency should be correct as shown and except for the number of significant digits displayed should be the same for both counter modes 4 7 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 12 BASIC FUNCTIONAL CHECKS Cent d Range MHz Counter Reading MHz 4 48 m Continue as in the preceding step except compare the counter reading for EXT 0 550 and INT COUNTER MODE Range MHz Counter Reading MHz 8 16 10 0 16 32 20 0 32 64 40 0 64 128 80 0 128 256 160 256 512 320 512 1024 640 INT 320 EXT 0 550 Set RANGE to 2
482. hed figure e P O A8A2 Figure 8 68 P O A8A2 Counter Lock Board Assembly Component Locations P O Change 1 Service Sheet 21 schematic Change part number for A8A2 subassembly to 08640 60189 Service Sheet 22 Principles of Operation Under Input Voltage A12 and A14 delete the last sentence and add the following paragraph The A12 Rectifier Assembly contains five ful wave rectifiers and a crowbar to protect the instrument from excessively high line voltages The crowbar is across the output of the rectifier bridge to the 44 6V regulator If the rectified voltage exceeds 75V breakdown diode 12 1 conducts and triggers the gate of SCR 1201 Q1 then conducts and blows the primary fuse Diode AI2CR21 prevents filter capacitor from discharging through the crowbar when the crowbar conducts Continued Model 8640B Option 004 08640 90073 CHANGE 1 Cont d Service Sheet 22 component locations Replace Figure 8 7 with the attached figure Figure 8 71 A12 Rectifier Assembly Component Locations P O Change 1 Service Sheet 22 schematic Replace appropriate portion of schematic with the attached partial schematic P O Figure 8 74 P O PWR SUP 12 RECTIFIER ASSY 08640 60190 t A12 RECTIFIER CRA P O Figure 8 74 Power Supply Circuits Schematic Diagram P O Change 1 7 29 Model 8640B Option 004 08640 90073 CHANGE 2 Page 6 7 T able 6 3 Add
483. here is insufficient clearance for the insulator between gears and capacitor perform step e e Remove back cover from the oscillator Then loosen three nylon screws which secure the tuning capacitor to the PC board This til allow a small amount of shift in the capacitor s position and afford clearance for the insulator Tighten nylon screws and reassemble back cover f Replace Audio Oscillator cover and rein stall A11 assembly see Semite sheet D g Perform Internal Modulation Oscillator Test Section IV If out of specification perform Variable Frequency Modulation Oscillator Adjust ment Option 001 in 7 26 Improvement in Lock Acquisition Capa bility Serial Number Prefixes 1350A and Below 7 27 The counter may fail to lock on random occasions This may be caused by the time base signal present at A8A2TP6 which might instantan eously exceed the phase lock error detector thresh old when going into the lock mode Should this occur connect a 1000 pF capacitor A8A2C31 HP Part Number 0160 3456 between the line connect ing to A8A2TP6 and ground Manual Changes 7 28 44 6V Regulator improvement Serial Number Prefixes 1405A and Below 7 29 Changing A20Q4 regulator transistor to one with a lower cutoff frequency will reduce the possibility of oscillation The recommended tran sister is HP 1853 0224 After modification per form the Power Supply Adjustment for the 44 6V supply Section 7 30 Line
484. high line voltages The crowbar is across the output of the rectifier bridge to the 44 6V regulator If the rectified voltage exceeds 75V breakdown diode VR1 conducts and trig gers the gate of SCR 1201 QI then conducts and blows the primary fuse 7 6 Model 8640B Option 004 Manual Changes MANUAL CHANGES CHANGE C Cont d Service Sheet 22 component locations Replac Figure 8 71 with the attached figure A12 1 17 eo E luus eS 1 ad ec ee t M d Figure 7 2 12 Rectifier Assembly Component Locations Backdating Change C Service Sheet 22 schematic Replace appropriate portion of schematic with attached partial schematic P O 17 PWR SUP MOTHER BD ASSY 08640 60001 12 RECTIFIER ASSY 08640 60003 _ _ _ RECTIFIER ASSY 08640 600031 _ NPUT m CR3 CROWBAR Figure 7 3 Al2 Rectifier Assembly Backdating Change C 7 7 Manual Changes Model 8640B Option 004 MANUAL CHANGES CHANGE C Cont d NOTE See paragraph 7 18 for recommended instrument modification Service Sheet 25 schematic Delete A13R6 CHANGE D Page 6 41 Table 6 3 The recommended replacement for MP73 is 08640 40067 NOTE For instruments with serial number prefixes 1333A and below changing MP73 Time Base Vernier Knob will also require changing ASA4R I Time Base Vernier Pot to HP part number 2100 0647 Since the new knob has a a larger ski
485. ich turns on A26A1Q8 Q9 and Q5 Detector Buffer Amplifier A26A1 Transistor Q1 and FET Q2 form a high impedance unity gain buffer amplifier Diode CR6 and resistor R19 add a dc offset which compensates for the junction voltage drop of the detector diode to linearize the detector Schmitt Trigger A26A2 A Schmitt Trigger formed by U1 and U2A converts the pulse input voltage into O to 5V pulses Resistors R20 and R21 set the trigger reference at about 0 5 Vdc When the input to U1 is above the ref erence the output of U2A is low When the input goes below the reference the output of U2A goes high 5 V Resistor R23 adds a small amount of hysteresis to the reference voltage In the normal pulse modulation mode NAND gate U2C inverts the trigger output and switches transistors A26A1Q4 and Q3 on when the input pulse is high or off when the input pulse is low Thus the charge on capacitor 26A1C6 is stored between pulses but is shunted by A26A1R23 when an input pulse is present Similarly NAND gate U2D inverts the trigger output and switches the Modulator Driver Amplifier A26A4 Service Sheet 12 Rate Detector A26A2 Flip flops U3A and U3B form a rate detector to turn off the RF level drive to the meter circuits whenever the pulse repetition rate falls below 20 Hz Below 20 Hz rates the output leveling system cannot accurately control the output amplitude The flip flops are arranged as retriggerable monostable one shot mu
486. idth to 10 kHz input attenuation to 0 dB frequency span per division scan width to 20 MHz scale to log 10 dB per division scale reference level controls to 50 dBm and scale center frequency controls to 100 MHz Calibrate the analyzer by using the scale reference level controls to set the 107 dBm signal from the generator to the 37 dB graticule line on the display Disconnect generator from analyzer and connect 50 ohm terminations to generator s input and output connectors including the AUX RF OUTPUT on rear panel Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 31 OUTPUT LEAKAGE TEST Cent d 3 Connect one inch loop antenna to analyzer through 0 5 400 MHz amplifier Hold end of loop antenna cylinder in contact with all surfaces of Signal Generator set analyzer s center frequency controls to 300 MHz and repeat All signals and noise should be below the 27 dB graticule line on analyzer s display below 97 dBm from 0 5 to 400 MHz 97 dBm 4 Replace 0 5 400 MHz amplifier with 400 1200 MHz amplifier Set analyzer s center frequency controls to 500 MHz set generator s RANGE control to 256 512 MHz and FREQUENCY TUNE control to 500 MHz and connect generator to analyzer and calibrate analyzer as specified in step 2 Then reterminate RF OUT reconnect loop antenna to analyzer and hold end of loop antenna cylinder in contact with all surfaces of generator All signals and noise should be below the 27 dB grati
487. ier or its external circuitry Usually this difference will be several volts and one of the inputs will be very close to an applied circuit operating voltage for example 20 V 12 V 8 72 Next check the amplifier s output voltage It will probably also be close to one of the applied circuit potentials ground 20 V 12 V etc Check to see that the output conforms to the inputs For example if the inverting input is positive the output should be negative if the non inverting input is positive the output should be positive If the output conforms to the inputs check the amplifier s external circuitry If the amplifier s output does not conform to its inputs it is probably defective 8 73 Comparator Comparators are used as sense amplifiers pulse height discriminators and voltage comparators A voltage reference is connected to one of the amplifier s inputs as shown in Figure 8 16 When the input signal voltage crosses the reference the output goes positive the output remains positive until the signal re crosses the reference Service Model 8640B Option 004 CU COUNT UP CD COUNT DOWN CLR MASTER CLEAR LD LOAD Da Dp DATA INPUT Qa p DATA OUTPUT CRY CARRY BRW BORROW Illustrated below is the following sequence 1 Clear outputs to zero 2 Load preset to 8CD thirteen 3 Count up to fourteen fifteen carry zero one and two MASTER 4 Count down to one zero borrow fifteen fourteen
488. ies 55 Reference Designations and Abbreviations 6 3 Replaceable Parts Table of Contents SERVICE SHEETS 6 5 Part Number National 668 Cross Reference Index References B Components of END Item List B 1 D Maintenance Allocation Page Service Sheet Page 8 18 15 AM Interconnections RF ON OFF Switch and Demodulation Amplifier 9 A26A8 16 Vernier 19 1 26 8 50 221 17 Meter Circuits 2 A4 D 18 Counter RF Scaler A8A1 19 Counter Time Base A8A3 A9 8 28 20 Up Down Counter amp Display A8A2 A8A4 21 Counter Phase Lock Circuits A8A2 8 34 22 Power Supply Circuits 12 14 A20 2 8 62 8 32 23 52 Regulator and Fan Circuits A16 18 24 Power Supply Mother Boa A17 8 67 25 Modulation Metering Mother Board A13 8 68 A Al and A19 Assemblies Removal and Disassembly 8 38 B A3 Assembly Removal and Disassembly L 8 72 C 8 Assembly Removal and Disassembly D A9 and All Assemblies Removal and Disassembly E 10 Assembly Removal and Disassembly i F A26 Assembly Removal and Disassembly 8 80 G General Removal Procedures and 8 44 Top Internal Views 8 82 8 46 H Rear Panel and Bottom Internal Views 8 85 TABLES Page Table Page 1 8 Code List of Manufacturers 6 45 1 14 Manual Changes by Serial Number 1 19 Summary of Changes Component L 7 2 Etched Circuit Solde
489. ified limits 1 22 Frequency within a band is selected with a FREQUENCY TUNE control of approximately 8 turns see Figure 3 2 for fast selection of the desired output frequency A mechanical FINE TUNE control has a tuning range of 1000 ppm for precision frequency setting Model 8640B Option 004 1 23 Restabilization time is short when tuning the frequency across any one band The total fre quency excursion after any frequency change is typically lt 20 ppm and within 15 minutes the output has restabilized to the specified 10 ppm 10 min When not phase locked no restab ilization time is required when switching frequency binds for a fixed position cm the frequency tune control 1 24 Noise performance of the generator is excel lent The high Q cavity oscillator has been optimized with use of a low noise microwave transistor for a spectrally pure output signal shows the typical measured single side band noise performance in a 1 Hz bandwidth for various offsets from a 256 and 512 MHz carrier The low close in noise characteristic is ideally suited for the stringent adjacent channel tests that are commonly made on a wide variety of communication receivers 1 25 Figure 1 3 gives a plot of the specified SSB noise perfomance for a 20 kHz offset from the carrier for the 256 512 MHz band From 230 to 450 MHz noise is gt 130 dB Hz below the carrier level and rises to 122 dB Hz at 500 MHz This signal to noise ratio decreases by
490. ifier Assy Annunciator Assy FM Shaping Assy Counter Lock Assy Peak Deviation and Range Switch Assy Divider Filter Assy Fixed F requency Modulation Oscillator Assy Standard Variable F requency Modulation Oscillator Assy Option 001 Rectifier Assy Modulation Metering Mother Board Assy Line Power Assy Riser Assy Fan Motor Assy Power Supply Mother Board Assy 5 2V Regulator and Fan Driver Assy Output Level 10 dB Assy 5 2V and 44 6V Regulator Assy 20V and 20V Regulator Assy Series Regulator Socket Assy AM AGC and RF Amplifier Assy Service Sheets 13 16 Service Sheet 17 Service Sheets 5 6 Service Sheet 17 Service Sheet 6 Service Sheets 8 17 Service Sheets 7 8 Service Sheets 18 19 20 21 Service Sheets 6 7 8 15 Service Sheets 10 11 Service Sheet 9 Service Sheet 9A Service Sheet 22 Service Sheets 6 9 9A 14 25 Service Sheet 22 Service Sheets 14 15 16 Service Sheet 23 Service Sheet 24 Service Sheet 23 Service Sheets 13 and 16 Service Sheet 22 Service Sheet 22 Service Sheet 22 Service Sheets 12 13 14 15 16 Odd numbered assemblies and sub assemblies are accessible from bottom of instrument Even numbered assemblies and sub assemblies are accessible from top of instrument See Service Sheets G and H for top and bottom internal views of instrument 2 Assembly principles of operation troubleshooting and component location photographs are given on the service
491. igure 5 13 FM Linearity Adjustment Alternate Test Setup EQUIPMENT FM Discriminator HPS210A Filter Kit For Discriminator HP 10531A Audio Spectrum Analyzer HP 141T 8552B 8556A PROCEDURE l Connect equipment as shown ip Figure 5 13 after setting Signal Generator s controls as follows Meter Function cob ae Xe COUNTER MODE EXPAND Wwe LOCK amp 4 c OEE Source oca VR SQ INT MODULATION FREQUENCY oW a ww amp 1 kHz Fixed FM Xx x PEAK DEVIATION PS S kHz PEAK DEVIATION Vernier cw Fully CW RANGE ju 2 s s s 0 5 1 MHz FREQUENCY TUNE a a d 0 7 MHZ OUTPUT LEVEL Switches 2 s 13 dBm OUTPUT LEVEL Vernier de CAE RF ON OFF 4 e NOTE If it is desired to optimize FM linearity at a frequency other than mid band proceed as follows a Set RANGE and FREQUENCY TUNE to the desired frequency b Set RANGE to 0 5 1 MHz 5 39 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 42 FM LINEARITY ADJUSTMENT Alternate Cont d 2 Using the filter kit prepare a 25 kHz Butterworth low pass filter and install it in the discriminator 3 Set the discriminator s range to 1 MHz and sensitivity to IV 4 Set spectrum analyzer s resolution bandwidth to 100 Hz and its center frequency con
492. imize flatness for a given frequency range The negative feedback path is a voltage divider in which the amount of feedback is determined by the output signal level The amount of feedback adjusts to maintain oscillation at a constant amplitude The voltage divider consists of R28 and RTI a thermistor assembly Diodes VR2 CR5 CR6 add a small amount of odd harmonic distortion to stabilize the amplitude characteristic of the oscillator Buffer Amplifiers Al 1 Transistors Q1 to Q4 form the AM FM Output Buffer Amplifier which is similar in operation to the oscillator output amplifier Gain of the amplifier is adjusted by R40 The outputs drive the external AM or FM ports Resistors R34 R35 and R36 attenuate the oscillator output to a level of Fixed Frequency Modulation Oscillator A11 A13 SERVICE SHEET 9 Service SERVICE SHEET 9A Cent d 0 84 Vrms Transistor Q5 drives the FM PEAK DEVIATION potentiometer Service Sheet 6 and Q6 drives the AM MODULATION potentiometer Service Sheet 14 TROUBLESHOOTING It is assumed that a problem has been isolated to the variable frequency modulation oscillator as a result of using the troubleshooting block diagrams Troubleshoot by using the test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital Voltmeter HP 3480D 3484A Oscilloscope 180A 1801A 1820
493. in RF oscillator a varactor assembly and two buffer amplifiers The output of the RF oscillator is applied to the RF OUT port through the AlO Divider Filter Assembly the A26 AM AGC and RF Amplifier Assembly and the 1 1 and A19A1 Output Attenuators see block diagrams for schematic locations Oscillator Loop The 230 and 550 MHz RF oscillator is a single transistor cavity tuned oscillator Integral with the oscillator assembly is a Varactor Head Assembly which provides electrical tuning for FM The high frequency transistor is in a common base configuration The emitter and collector loops couple into the cavity and to each other to provide the positive feedback necessary for oscillation Tunable Cavity The cavity is a foreshortened type which is essentially a length of coaxial transmission line with a short at one end and a capacitive load at the other The shorted transmission line is less than 1 4 wavelength long at the frequency of oscillation and its impedance is inductive The cavity resonates at the frequent y at which the inductive reactance of the transmission line equals the capacitive reactance of the load capacitor The resonant frequency is varied by changing the length of the cavity a secondary effect and by changing the load capacitance The varactor diodes are in parallel with the main load capacitance The cavity is mechanically fine tuned by protruding a small metal slug into the cavity Signal is coupled out of the
494. in the back of this manual direct to Commander US Army Com munications and Electronics Materiel Readiness Command and Fort Monmouth ATTN DRSEL ME MQ Fort Monmouth NJ 07703 In either case a reply will be furnished direct to you This manual is an authentication of the manufacturer s commercial literature which through usage has been found to rover the data required to opersaate and maintain this equipment The manual was not prepared in accordance with military specifications therefore the format has not been structured to consider categories of maintenance Model 8640B Option 004 ction INTRODUCTION GENERAL INFORMATION Elle 1 1 ntroduction 6 Specifications 8 Instruments Covered by Manual 1 13 General Description 1 19 Performance Characteristics 1 20 Spectral Purity Frequency Counter 1 31 Phase Lock Mode Amplitude Modulation Pulse Modulation 1 45 Frequency Modulation Standard and Optional Audio Oscillators Multi Function Meter and Annunciators 0 57 Output Level 1 65 Accessories Supplied 1 69 Bquipment Available 76 Service and User Aids 1 82 Test Equipment Required E INSTALLATION 2 1 _ Introduction D Initial Inspection 2 5 Preparation for Use Power Requirements Line Voltage Selection Power Cable Mating Connectors Operating Environment Bench Operation Rack Mounting p I
495. ing on circuit boards for general purpose work use Ungar No 4037 Heating Unit 47 V 56 4W tip temperature of 850 900 degrees and Ungar No PL113 1 8 chisel tip General Electric Co Silicone Products Dept Waterford New York U S A Model 8640B Option 004 8 32 If component was unsoldered remove solder from mounting holes and position component as original was positioned DO NOT FORCE LEADS INTO MOUNTING HOLES sharp lead ends may damage plated through conductor 8 33 Transistor Replacement Transistors are packaged in many physical forms This sometimes results in confusion as to which lead is the collector which is the emitter and which is the base Figure 8 2 shows typical epoxy and metal case transistors and the means of identifying the leads 8 34 To replace a transistor proceed as follows a Do not apply excessive heat sed Table 8 1 for recommended soldering tools b If possible use long nose pliers between transistor and hot soldering tools c When installing replacement transistor ensure sufficient lead length to dissipate soldering heat by using about the same length of exposed lead as used for original transistor d Integrated circuit replacement instruc tions are the same as those for transistors 8 35 Some transistors are mounted on heat sinks for good heat dissipation This requires good thermal contact with mounting surfaces To assure good thermal contact for a replacement trans
496. ings 6 Remove connector A9P1 from jack on A13 Assembly Lift out A9 Assembly 7 Reinstall assembly by setting both switch shafts fully counterclockwise and reversing the procedures in steps one through six NOTES l The detents of both the A9 Assembly and Al O Assembly switches must align and correspond to the same positions Check that the actual RF output fre quency agrees with the counter indica tion on all bands 2 Adjust the coupler longitudinally for minimum binding and tighten the set screws very securely A11 Assembly Removal Procedure All Removal Standard 1 Remove bottom cover from instrument see Service Sheet G 2 Set MODULATION FREQUENCY knob to 400 Hz Remove MODULATION FRE QUENCY knob The knob is secured to its shaft with allen screws Model 8640B Option 004 3 Remove Al 1 Assembly by gently lifting the board extractor at rear of board and sliding assembly to the rear and out of chassis 4 To connect Al 1 Assembly for service place assembly on extender board and install in chassis Reinstall MODULATION FRE QUENCY knob with 400 Hz position toward top of instrument All Removal Option 001 1 Remove top and bottom covers from instru ment see Service Sheet G 2 Set MODULATION FREQUENCY knob to 400 Hz fixed Remove MODULATION FRE QUENCY knob vernier knob and cursor disc and gear The knobs are secured to concentric shafts with allen screws in the knobs CAUTION When r
497. into the modulator through T1 and out through T2 The modulator output drives the RF filters Service Sheet 10 AGC Amplifier A26A4 The AGC Amplifier sums the negative detector output from the A26A Detector Buffer Amplifier Service Sheet 13 with the positive AGC reference voltage from the OUTPUT LEVEL vernier AIRI Service Sheet 16 The input to the vernier is a 2 Vdc signal 2 Vpk for 100 AM When AM is set to PULSE the amplifier s output and therefore the modulator is switched on and off by the input pulses Summing Amplifier Transistors Q1 Q2 and form a Summing Amplifier The output of Q3 is the amplified sum of the detector and reference currents and represents the output level error Resist or R 1 is adjusted to give the correct RF output voltage corresponding to the AGC reference Switch 51 allows the AGC circuits to be tested in an open loop condition Modulator Driver Amplifier Transistors Q4 Q 5 and Q6 form the high gain Modulator Driver Amplifier R56 R57 R32 C18 and C9 frequency compensate the AGC system Capacitor CIO is switched in parallel with C9 in the 0 5 1 and 1 2 MHz ranges called LO BAND 1 to give added compensation The LO BAND 1 line is grounded in LO SERVICE SHEET 12 Cont d BAND 1 ranges and causes inverter U3B to go high and inverter U4F an open collector output gate to go low which switches in C10 In a similar manner capacitor 1 is switched in parallel with C9 in the 2
498. isconnect instrument from the line power source Remove test cables reconnect cable W7 to jack A26W3 and replace bottom cover Connect instrument to line power source Allow one hour warm up time before continuing with this or other test Check Signal Generator for correct RF output on each frequency range Capacitors inside the instrument may still be charged even if the instrument has been disconnected from its line power source Model 864013 Option 004 Performance Tests PERFORMANCE TESTS 4 38 DEMODULATED OUTPUT ACCURACY TEST SPECIFICATION Demodulated Output OUTPUT LEVEL Vernier in CAL position 108 to 118 MHz and 329 to 335 MHz carrier and between 20 and 80 AM An internal selector switch allows selection of ac only or ac and dc at the demodulated output AC only output Directly proportional to AM depth 90 to 150 Hz modulation rate AM equals 20 0 6 per Vrms 0 to 55 C 20 0 4 per Vrms 20 to 30 C 20 0 2 per Vrms 20 to 30 C using DEMOD CAL Label provided by factory AC and DC output AC output voltage is directly proportional to AM depth 90 to 150 Hz modulation rate AM equals 100 3 per Vrms 0 to 55 C 100 2 per Vrms 20 to 30 C 100 1 per Vrms 20 to 30 C using DEMOD CAL Label provided by factory DC output equals 1 414 0 010 Vdc with vernier in CAL position DESCRIPTION The Signal Generator is amplitude modulated and the modulation is demodulated by
499. iscriminator 5 Connect amplifier to discriminator output Connect the voltmeter through the 15 kHz LPF to amplifier s output The signal out of the amplifier is 0 5 mVrms per 1 Hz rms of residual FM deviation and the average voltmeter reading should be less than 7 5 mVrms ie 15 Hz rms residual FM 7 5 mVrms NOTE Test setup calibration can be checked by setting the test generator s FM to INT PEAK DEVIATION to 5 kHz vernier fully cw and MODULATION FREQUENCY to 1000 Hz The voltmeter should read 1 77 Vrms 6 connect the capacitor between amplifier and filter Replace 15 kHz LPF with 3 kHz LPF The average voltmeter reading should be less than 2 5 mVrms i e 5 Hz rms residual FM 2 5 mVrms 7 Set test Signal Generators PEAK DEVIATION switch to 2 56 MHz The average voltmeter reading should be less than 7 5 mVrms 1 15 Hz rms residual FM 7 5 mVrrns 8 Remove the capacitor and replace 3 kHz LPF with 15 kHz LPF The average voltmeter reading should be less than 15 mVrms i e 30 Hz rms residual FM 15 mVrms 4 33 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 25 OUTPUT LEVEL ACCURACY TEST Abbreviated SPECIFICATION Range A 10 dB step attenuator and a 1 dB step attenuator with a vernier allow selection of output levels from 15 dBm to 142 dBm 1 3V to 0 018 uV into 500 Level Accuracy Total Accuracy as Indicated on Level Meter DESCRIPTION The RF
500. istor coat both sides of the insulator with Dow Coming No 5 silicone compound or equivalent before fastening the transistor to the chassis Dow Coming No 5 compound is available in 8 oz tubes from Hewlett Packard order HP Part No 8500 0059 8 36 Diode Replacement Solid state diodes have many different physical forms This sometimes results in confusion as to which lead is the anode positive since not all diodes are marked with the standard symbols Figure 8 2 shows examples of some diode marking methods If doubt exists as to polarity an ohmmeter may be used to determine the proper connection It is necessary to know the polarity of the ohms lead with respect to the common lead for the ohmmeter used For the HP Model 410B Vacuum Tube Voltmeter the ohms lead is negative with respect to the common for the HP Model 412A DC Vacuum Tube Voltmeter Service the ohms lead is positive with respect to the common When the ohmmeter indicates the least diode resistance the cathode of the diode is connected to the ohmmeter lead which is negative with respect to the other lead NOTE Replacement t instructions are the same as those listed for transistor replacement 8 37 Illustrated Parts Breakdowns 8 38 Illustrated parts breakdowns for the genera tors major assemblies are given on Service Sheets A through F They are keyed to disassembly and removal instructions given on the alphabetical service sheets and to the replace
501. istortion Test Option 001 22 4 34 AM 3 dB Bandwidth Test 4 35 AM Distortion Test 4 36 Sensitivity and Accuracy Test 73 4 37 Peak Incidental Phase Modulation Test 4 38 Demodulated Output Accuracy Test 2 3 139 AM Phase Shift Test 23 4 40 AM Flatness Test 14 4 Pulse Modulation Test EA 4 42 Hulse On Off Ratio Test 4 43 BM 3 dB Bandwidth Test 3 1 Distortion Test 4 45 FM Sensitivity and Accuracy Test 4 46 Ihcidental AM Test oa ounter External Sensitivity Test 1 TI 14 48 Internal Reference Accuracy Test 4 49 Internal Reference Drift Rate Stability Test mi 4 50 Phase Lock Restabilizotion Time Test 4 1 ADJUSTMENTS La 5 Introduction E os 5 3 Safety Considerations 5 9 Test Equipment Required Posidriv Screwdrivers 4 28 JOutput Impedance Test Signal 4 32 Internal Modulation Oscillator Test 5 No 1 1 1 foo ION P IISI T NI 55 0S I2 I n aN J JNO I in 1 4 62 4 69 4 77 4 7 4 7 4 8 4 8 4 87 lbo loo 4 8 14 92 E Table of Contents Model 8640B Option 004 CONTENTS cont d Section ADJUSTMENTS cont d Blade Tuning Tools 5 15 Service Aids Foe
502. it is necea 1 5 General Information sary to reduce either the OUTPUT LEVEL 10 dB switch or the AM MODULATION control 1 55 The REDUCE PEAK DEVIATION annunci ator lights whenever the PEAK DEVIATION RANGE switch has been set to exceed the allow able limits for any output FREQUENCY RANGE The specification allows for a maximum peak deviation of 1 of the minimum frequency in each band e g 2 56 MHz on the 256 512 MHz band When the annunciator lights the FM is automatic ally turned off and the FM meter reads zero 1 56 The REDUCE FM VERNIER annunciator lights whenever the FM input and FM vernier setting combine to exceed the 1 volt drive level required to achieve the maximum deviation in dicated on the PEAK DEVIATION range switch When this occurs either the FM vernier or the amplitude of the incoming modulation signal should be reduced to obtain specified FM performance 1 57 Output Level 1 58 The wide output range of the generator is achieved with a 20 dB step attenuator a 1 dB step attenuator and a 2 dB vernier Output levels can be read directly on the attenuator dials or for greater accuracy on the autoranging meter The meter scales are automatically selected to give the maxi mum indicator resolution for any output level 1 59 The maximum output level of 15 dBm permits high level tests on receiver IF s amplifiers and mixers without additional power amplifica tion At the same time extremely low lea
503. it that way 2 Adjust mechanical zero adjustment screw on panel meter clockwise for a zero meter reading Then turn screw slightly counterclockwise to free mechanism from adjusting peg 3 Set generator s controls as follows Meter Function FM FM OFF MODULATION FREQUENCY 1000 Hz PEAK DEVIATION 10 kHz PEAK DEVIATION Vernier Fully ccw RANGE 2 4 MHz LINE ON 4 Connect DVM to DC OUT test point A2TP2 on A2 Meter Switch Detector Assembly Adjust DET OFFSET pot A2R5 for O Vdc 1 mVdc at A2TP2 5 Connect DVM to MTR ADJ test point A4TP1 on A4 Meter Annunciator Drive Assembly Adjust DRIVER OFFSET pot A4R10 for 0 Vdc 1 mVdc at A4TPI 6 Set FM to INT Adjust PEAK DEVIATION vernier clockwise until DVM reads 9 766 Vdc at Then adjust F S METER pot A4R19 for a full scale reading 10 on the 0 10 scale on the panel meter Model 8640B Option 004 ADJUSTMENTS 5 29 RF DETECTOR OFF SET ADJUSTMENT REFERENCE Service Sheets 13 and 14 DESCRIPTION Adjustments A dc voltage applied to the AM INPUT is set to vary the AGC reference by 20 dB The RF output level is monitored and the detector offset is adjusted so that the RF level varies 20 dB as the AGC reference is varied DIGITAL VOLTMETER SPECTRUM ANALYZER 9 nS ces ae se STEP 1 POWER SUPPLY l 2222222 P 000 Figure 5 1 RF Detector Offset Adjustment Test Setup EQUIPMENT Spect
504. ith covers removed Figure 8 36 A11 Variable Frequency Modulation Oscillator Assembly Option 001 Component Locations A13 Component Locations for A13 Assembly are on Service Sheet 25 PIO AB 1 MODULAT JON METERING MGTHER BOARD ASSY ee TREGUERCY WOQULATIDN GECILLATQM OFTIDM MAAL OPTION 20V m e a m RM 215K 20V 2 EIN cls IMF FAM OUTPUT BUFFER Lose 20 ET RIT We 464 HAY 3160 Es 5 10 15 CRI eb git mem Ns 1852 0050 i Rss 56 2 R54 00 R32 1000 OSC QUT 4 AV FD Q9 9 45103Vp p 1000 196K 38 R39 215K BM 2 a AUDIO ayy 502 CRS OUTPU R26 LEVEL RX R M TK 261 3480 NT FM BUFFER Sr YRI B 38V 3 8 m ANH C15 ET FM QUT ead R53 NT AM BUFFER 0 RI 2610 PIO AIS _ REFERENCE DESIGNATIONS C1 23 CR1 10 quu R1 28 30 56 i RTL i TP1 6 VR1 2 DELETED ALIR 9 NOTES 1 1 THE COMBINED CAPACITANCE OF 14 acis AND 15 APPROX AM IMATELY 10 365 pF SEE BACKDATING TABLES 7 1 AND 1 2 REFERENCE DESIGNATIONS OUTLINED mae i mmi ASSEMBLIES ARE ABBREVIATED FULL D SIGNATION IN CLUDES ASSEMBLY NUMBER
505. ithin the borderlines of circuit assemb lies signify connections to the assembly which are separate from those made through the integral plug part of the assembly Assembly reference designator s Large numbers in lower right corners of schematic diagrams are service sheet numbers They are provided for con List of all the reference desig venience in tracing inter nations on the diagram connections Reference designators deleted by circuit changes are listed here 8 17 Service SERVICE SHEET 1 PRINCIPLES OF OPERATION General Refer to Figure 8 17 The Model 8640B Option 004 Signal Generator is a mechanically tuned solid state RF signal source producing signals from 0 5 to 512 MHz The RF Oscillator operates within a basic frequency band of 256 to 512 MHz which can be divided into nine additional octave bands from 0 5 to 256 MHz The leveled output may be attenuated in 1 db steps from 15 to 142 dBm and continuously varied over a 2 dB range by a vernier a function of the AM AGC circuits Calibrated AM and FM either internal or external are provided External pulse modulation with calibrated output level is provided by the AM AGC circuits In addition a very accur ate demodulated AM output is provided The RF output frequency is read on an internal counter which may also be used to count external signals up to 550 MHz and to phase lock the generator to a stable reference oscillator FM Circuits and RF O
506. itivity 1 volt peak yields maximum deviation indicated on PEAK DEVIATION switch with FM vernier at full cw position External FM Sensitivity Accuracy 6 from 15 to 35 C for FM excluding maximum peak deviation position Maximum peak deviation position 9 typically Indicated FM Accuracy 400 Hz and 1 kHz rates using internal meter 10 of meter reading for greater than 10 of full scale DESCRIPTION The Signal Generator s FM sensitivity is checked using the carrier Bessel null technique An externally applied 1 Vpk signal is used to FM the generator The modulation signal s frequency is adjusted for the first order null of the carrier and the frequency is measured to find peak deviation For the first order null of the carrier peak deviation equals 2 405 times the modulation rate The panel meter accuracy is found by comparing its reading to the given peak deviation The reference generator and mixer convert the signal into the range of the spectrym analyzer See Recommended Test Abridgements 4 81 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 45 FM SENSITIVITY AND ACCURACY TEST Control NOTE The ambient temperature must be within 15 to 35 C for this test STEP 1 ag o ANALYZER J STEP 6 DIGITAL VOLTMETER FREQUENCY COUNTER OUTPUT Figure 4 30 FM Sensitivity and Accuracy Test Setup EQUIPMENT Test Oscillator HP 652A
507. kage ensures receiver sensitivity measurements down to levels of 0 03 uV in a shielded system 1 60 For improved accuracy at low output levels the meter in conjunction with the attenuators is factory calibrated against a precision standard to remove much of the error that is accumulated from the attenuator s steps Using a power meter and calibrating the output for one output frequency and vernier setting it is then possible to make sensitivity measurements to better than 1 dB accuracy down to output levels of 127 dBm 1 61 OPTIONS 1 62 Option 001 Option 001 covered in this manual provides a modulation oscillator that is continuously settable from 20 Hz to 600 kHz The 1 6 Model 8640B Option 004 oscillator can also be set for 400 Hz or 1 kHz fixed tones 1 63 Option 002 Option 002 an internal fre quency doubler available in the standard Model 8640B is not compatible with the Model 8640B Option 004 and thus is not covered in this manual 1 64 Option 003 Option 003 either factory built or retrofitted protects the generator s output cir cuits from accidental applications of reverse power up to 25 watts Option 003 is documented in a separate manual supplement 1 65 ACCESSORIES SUPPLIED 1 66 The Model 8640B Option 004 is supplied with the following accessories they are shown in Figure 1 1 Rack Mounting Kit HP 5060 8740 Line Power Cable HP 8120 1378 2 Amp Fuse HP 2110 0002 1 25 Amp
508. l load ing FM offset null constant under normal lab environment Sub harmonics and Non Omit test harmonic Spurious Test No mechanism for generation of spurious signals except counter which is heavily shielded and filtered 421 Single Sideband Phase None Noise Test Single Sideband Broad band Noise Floor Test Residual AM Test Omit step 4 Residual FM Test Omit steps 6 and 7 1 Normally within specification for 300 Hz to 3 kHz bandwidth if within specification for 20 Hz to 15 kHz bandwidth Normally within specification for 300 Hz to 3 kHz bandwidth if within specification for 20 Hz to 15 kHz bandwidth Output Level Accuracy None Test Abbreviated output Level Accuracy Omit test Test Complete Output Level Flatness Test Most useful ranges checked by abbreviated test Model 8640B Option 004 Performance Tests Table 4 1 Recommended Test Abridgements 2 of 3 Output Impedance Test Signal Frequency Omit one test A condition that is out of specification will Output Impedance Test usually show on both tests Broadband Auxiliary Output Test Omit test Auxiliary output a secondary function Output Leakage Test Omit step 5 and use The 400 MHz amplifier bandwidth is adequate 400 MHz amplifier to check leakage over the output range of 0 5 to check to 512 MHz to 512 MHz in step 4 Internal Modulation Omit test Exactness of modulation frequency not critical Oscillator Test for most applica
509. lator Assembly may be repaired to the component level However if a problem has been isolated to components in the RF Oscillator cavity the oscillator assembly should be returned to Hewlett Packard for repair Do not attempt to disassemble it because proper reassembly depends upon specialized skills and procedures Buffer Amplifiers Refer to Service Sheet B for access to the buffer amplifier assemblies Check dc bias voltages to reveal a faulty component See Section for adjustment 8 26 Model 8640B Option 004 RF ON OFF Switch Modification The RF ON OFF Switch function may be wired to a switch off both the RF Oscillator and Modulator leaving the RF output completely off but requiring a stabilization period after turn on or b switch off only the Modulator leaving the RF Oscillator on and warmed up the Auxiliary RF Output on and the counter and phase lock operating In this case however the RF is not truly off but is reduced by an amount equal to the pulse on off ratio at least 40 dB down and dependent on OUTPUT LEVEL vernier setting Either configuration can be easily altered to the other as follows a Remove bottom cover see Service Sheet G b Remove two nuts that secure A3A4 Connector Board Assembly and remove board The board is located directly behind the Range Switch cam housing c To modify the circuitry to leave the RF Oscillator on at all times add a jumper wire between the t
510. ld help you to quickly service and repair the Signal Generator 8 5 PRINCIPLES OF OPERATION 8 6 Principles of operation appear on the foldout pages opposite the block diagrams and the sche matics on the Service Sheets Service Sheet 1 is an overall block diagram that briefly describes overall instrument operation It is keyed by the numbers in the lower right hand corners of the blocks to the detailed block diagrams They provide an assembly by assembly description of instru ment operation 8 7 The detailed block diagrams in turn are keyed to the schematics on the Service Sheets that follow them These Service Sheets provide a stage by stage description of the circuits on the schematics The stages are keyed to the descrip tions by the stage names that appear on the schematics NOTE Table 8 8 Schematic Diagram Notes ex plains any unusual symbols that appear on the schematics The table also explains the switch wafer numbering system 8 8 TROUBLESHOOTING 8 9 This manual provides two methods to isolate a problem to a particular assembly The first method is to use the results of the performance tests given in Section IV and the table of Post Repair Performance Tests and Adjustments found in More information about this method is given in 8 10 Overall Troubleshooting The second and primary troubleshooting method is to use the overall block diagram found on Service Sheet 1 and the troubleshooting block
511. leads of replacement t component one turn around original leads Solder wrapped connection and clip off excess lead 8 3 Service Model 8640B Option 004 FIELD EFFECT TRANSISTORS BI POLAR TRANSISTORS METAL BLACK EPOXY METAL CASE PLASTIC BLACK EPOXY PLASTIC TRANSISTORS DIODES DIODE SYMBOL ANODE CATHODE STRIPE M N N CONICAL CATHODE CATHODE END dr METAL CASE TRANSISTORS DUAL ai B THODE CATHODE E B 1 es gt Pes N CATHODE CATHODE SHIELD E Figure 8 2 Examples of Diode and Transistor Marking Methods Table 8 1 Etched Circuit Soldering Equipment Soldering tool Soldering unsoldering Wattage range 37 50 Tip Temp 750 800 Ungar 766 handle w Ungar 1237 heating unit Soldering Tip Soldering unsoldering Shape pointed Ungar PL111 De soldering To remove molten solder Suction device Soldapullt by Edsyn Co Arleta California Aid from connection Resin flux Remove excess flux from Must not dissolve etched circuit base board Freon Acetone Lacquer Thinner Solvent soldered area before ap plication of protective coating Component replacement Resin flux core high tin content 60 40 Circuit board repair tin lead 18 gauge AWG preferred Wiring Protective Contamination corro Good electrical insulation corrosion Silicone Resin such as GE DRI FILM 88 sion protection prevention properties For work
512. level accuracy for the upper four OUTPUT LEVEL 10 dB ranges is measured with a power meter For the lower ranges a reference signal is established on a spectrum analyzer display the Signal Generator s OUTPUT LEVEL 10 dB switch and the spectrum analyzer s vertical scale log reference level control are stepped together and any amplitude variations are measured on the analyzer s display An RF attenuator and amplifier at the RF OUT are adjusted for analyzer compatibility and best sensitivity This procedure uses an IF substitution technique in which the spectrum analyzer s IF is the standard The IF step accuracy should be within 0 2 dB overall The IF step accuracy can be checked using the above technique by comparing a lab calibrated attenuator such as HP Model 355D Option H36 with the IF step control at the frequency of attenuator calibration e g 3 MHz for the HP 355D Option H36 NOTE This procedure checks output level accuracy from 15 dBm to 130 dBm all of the attenuator sections in the OUTPUT LEVEL step attenuators and the OUTPUT LEVEL Vernier If in addition level accuracy must be verified down to 142 dBm see paragraph 4 26 10 dB STEP 20 dB 20 dB ATTENUATOR AMPLIFIER AMPLIFIER ster 5 POWER METER DUUBLE SHIELDED CABLE T STEP 2 POWER SENSOR bw Figure 4 10 Output Level Accuracy Test Setup Abbreviated 4 34 Model 8640B Option 004 Performa
513. ll counters at the state of nine and the time of occurance of the underflow is compared with the termination of the time base cycle in the Null Phase Detector at the underflow the counter is 8 24 Model 8640B Option 004 once again preset from the buffers and continues counting toward zero The error from the detector adjusts the tuning of the RF Oscillator Service Sheet 2 to bring the average error to zero When the Error Detector senses the tuning voltage nearing its limit phase lock is broken the counter reverts to the normal count up mode and the Flash Oscillator is enabled which blinks the dis play TROUBLESHOOTING It is assumed that a problem has been isolated to the counter lock circuits as a result of using the overall block diagram Troubleshoot by using the test equipment and procedures specified below Test Equipment Digital Voltmeter HP 3480D 3484A Oscilloscope 180A 1801A 1820C Frequency Counter HP 5327C Initial Test Conditions Top and bottom covers removed see Service Sheet G Procedure Set the generator s controls as listed in the box at the right hand side of the diagram To check a voltage at a test point change the control settings as specified in the box associated with that test point check the voltage then reset the controls to the settings specified in the box at the right hand side The blocks are keyed by the numbers located in their lower right hand c
514. llator HP 204D 4 69 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 39 AM PHASE SHIFT TEST Cont d 1 Connect the equipment as shown in Figure 4 23 after setting the Signal Generator s controls as follows Meter Function AM COUNTER MODE EXPAND i po l ro Off LOCK s s a a 4 xy X amp e ow x we Source AM nee E 0 aoe GS a d UR ok MODULATION Fully cew FM OFF RANGE 2 25 5 5 5 64 128 MHz FREQUENCY TUNE 3 113 MHz OUTPUT LEVEL Switches 0 dBm OUTPUT LEVEL Vernier RF ON OFF LON 2 The internal AC DC switch should be set to AC i e 0 Vdc at DEMOD OUTPUT if not disconnect the instrument from the line power source Remove generator s top cover and the top cover from the A26 casting Set the switch to AC Replace covers and connect instrument to line power source Allow one hour warm up time before continuing with this test WARNING Capacitors inside the instrument may still be charged even if the instrument has been disconnected from its line power source 3 Set the test oscillator output to approximately 2 5 Vrms at 10 kHz and adjust MODULATION for a meter indication of 607 AM 4 Set the oscilloscope s horizontal axis to sweep from an external input
515. llocated the tool or test equipment c Nomenclature This column lists the noun name and nomenclature of the tools and test equipment required to perform the maintenance functions d National NATO Stock Number This column lists the National NATO stock number of the specfic tool or test equipment e Tool Number This column lists the manufacturer s part number of the tool followed by the Federal Supply Code for manufacturers 5 digit in parentheses D 5 Remarks Sec IV a Reference Code This code refers to the appropriate item i eerie II column 6 b Remarks This column provides the required ex planatory information necessary to clarify items appearing insection Next printed page is D 3 11 625 2780 146 SECTION 11 MAINTENANCE ALLOCATION CHART FOR SIGNAL GENERATOR SG 1112 V 1 U and SG 1112 V 2 U 4 1 2 3 MAINTENANCE CATEGORY GROUP COMPONENT ASSEMBLY MAINTENANCE NUMBER FUNCTION SIGNAL GENERATOR SG 1112 V 1 U and SG 1112 V 2 U nspect Test Test 3 1thru 12 Service Adj ust Repl ace Repair Repair Overhaul OUTPUT LEVEL ASSEMBLY AI Test Repair METER SW DETECTOR ASSEMBLY A2 Test Repair RF OSCILLOSCOPE ASSEMBLY A3 Test Repai METER ANNUCIATOR DRIVE ASSEMBLY 4 Test Repai FM AMPLIFIER ASSEMBLY A5 Test Repai ANNUNCIATOR ASSEMBLY A6 Test Repai FM SHAPING BOARD ASSEMBLY A7 Test Repai COUNTER LOCK X ASseweLY Test Repai PEAK DEVIATION ANO RA
516. llowed to ensure safe operation and to retain the instrument in a safe condition see Cautions Warnings page in the front of the man ual Service and adjustments should be performed only by qualified service personnel Any interruption of the protective grounding conductor inside or outside the instrument or disconnection of the protective earth terminal is likely to make the apparatus dangerous In tentional interruption is prohibited 5 5 Any adjustment maintenance and repair of the opened instrument under voltage should be avoided as much as possible and when inevitable should be carried out only by a skilled person who is aware of the hazard involved The opening of covers or removal of parts except those to which access can be gained by hand may expose live parts and also accessible terminals may be live 5 6 Capacitors inside the instrument may still be charged even if the instrument has been discon nected from its source of supply 5 7 Make sure that only fuses with the required rated current and of the specified type normal blow time delay etc are used for replacement The use of repaired fuses and the short circuiting of fuseholders must be avoided 5 8 Whenever it is likely that the protection has been impaired the instrument must be made inoperative and be secured against any unintended operation 5 9 TEST EQUIPMENT REQUIRED 5 10 Tables 1 2 and 1 3 contain a list of test equipment and test acc
517. llows Meter Function AM COUNTER MODE EXPAND PP eee cu 2o LOCK Source Sad OFF Modulation i it Fully ccw MODULATION FREQUENCY 1 kHz FM wn See 542 4 OFF RANGE 256 512 MHz FREQUENCY TUNE 512 MHz OUTPUT LEVEL Switches 17 dBm OUTPUT LEVEL Vernier CAL RF ON OFF 4 58 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 35 AM DISTORTION TEST Cont d 2 Set spectrum analyzer s resolution bandwidth to 300 kHz input attenuation to 20 dB frequency span per division scan width to 10 MHz scale to linear and adjust center frequency and scale reference level controls to center the 512 MHz signal on the display Set frequency span per division to O Hz and display smoothing video filter to 10 KHz Peak trace on display with center frequency controls set trace to the center of display with referenced level controls 3 Set generator s AM switch to INT and adjust MODULATION control for 50 modulation as read on generator s panel meter 4 Calibrate the distortion analyzer for 1 kHz Measure and record distortion it should be less than 1 with trace peaked on analyzer display 196 5 Use generators MODULATION control to set percent AM to 90 calibrate the distortion analyzer and measure distortion Di
518. low On each range set FREQUENCY TUNE to the low end of the band and use analyzer s frequency controls to set the fundamental to the left edge of the display Keeping the fundamental near the left edge of the display tune FREQUENCY TUNE to the high end of the band All harmonics should be as specified NOTE On bands 8 16 MHz and above check for harmonics while tuning down in frequency For frequencies above 500 MHz tune analyzer to observe second harmonic Spectrum Analyzer Signal Generator Resolution Bandwidth Freq Span Per Division Range 1 2 MHz 2 4 MHz 4 8 MHz 8 16 MHz 16 32 MHz 32 64 MHz 64 128 MHz 128 256 MHz 256 512 MHz 4 20 SUB HARMONICS AND NON HARMONIC SPURIOUS TEST SPECIFICATIONS Sub Harmonics and Non Harmonic Spurious excluding frequencies with 15 kHz of carrier whose effects are specified under Residual AM and FM gt 100 dB below carrier DESCRIPTION A notch filter is used to remove the fundamental All non harmonic spurious and sub harmonics are then amplified and measured with a spectrum analyzer See able 4 1 Recommended Test Abridgements 4 23 Performance Tests PERFORMANCE TESTS 4 20 SUB HARMONICS AND NON HARMONIC SPURIOUS TEST Cont d NOTCH FILTER Model 8640B Option 004 SPECTRUM ANALYZER MODEL 86408 OPTION 004 20 dB 2 M STEP AMPLIFIER 2 ATTENUATOR Figure 4 5 Sub Harmonics and Non Harmonic Spurious Test Setup EQUIPMENT 520 1040 MHz Notch
519. lso the series pass transistor base emitter junction is not in the current foldback circuit resulting in a larger short circuit output current 20V Regulator A22 The 20V regulator functions identically ta the 20V regulator except that the 20V output is taken from the point correspond ing to the ground point on the 20V regulator and the 20V ground return is connected to a point thai corresponds to the 20V output Also 20V regulator uses V R3 for a reference 44 6V Regulator A20 The 44 6V regulator functions similarly to the 5 2V regulator except that the output voltage is reduced by the voltage divider formed by R8 and R9 and is applied to the non inverting input of the comparison amplifier of U2 pin 3 The reference voltage is applied to the inverting input pin 2 The Series Regulator transistor Q3 chassis mounted is in the regulator return line and is driven by Q4 The two transistors are in an inverted Darlington configuration which is common emitter instead of emitter follower as in the 5 2V regulator Components Q3 Q6 R1 and R2 form a constant current source which sinks the current from pin 6 of U2 and the base of Q4 Q5 provides foldback eurrent limiting TROUBLESHOOTING It is assumed that one of the light emitting diodes is not lit or thai ripple noise or voltage from one of the power supplies is suspect Troubleshoot by using the test equipment listed below perform ing the i
520. ltivibrators with timing elements R25 and C10 and R28 and Cll A low going output from U2A triggers U3A and the Q output of U3A goes low for 50 ms If the repetition rate of the incoming pulses is higher than 20 Hz U3A retriggers and the Q output remains low In the absence of pulses from the Q output of U3A the Q output of U3B is low transistor Q7 is off and the meter operates normally For pulse repetition rates less than 20 Hz U3B is periodically triggered by the Q output of U3A The Q output of U3B goes high for 100 ms or longer if U3B is retriggered by U3A and turns on Q7 which disables the meter drive amplifier output and the meter reads zero Thus the meter is turned off for low rate pulses When not in the pulse modulation mode the output of inverter U2B is low the output of U2C is high and A26A1Q1 is held on the output of U2D is high and the modulator is held in its normal on mode and Q7 is held off SERVICE SHEET 13 Cont d TROUBLESHOOTING It is assumed that a problem has been isolated to the power amplifier and AGC detector or to the AM offset and pulse switching circuits as a result of using the troubleshooting block diagrams Troubleshoot by using the test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital HP 3480D 3484A Oscilloscope 180A 1801A 1820C Pulse
521. mbered Test point Meas Lettered Test point No urement aid metal post measurement aid provided circuit pad etc provided Encloses wire color code Code used is the same as the resistor color code First number identifies the base color second number identifies the wider stripe third number identifies the narrower stripe E g 4lanotes white base yellow wide stripe violet narrow stripe A direct conducting connection to the earth or a conducting connection to a structure that has a similar function e g the frame of an air sea or land vehicle A conducting connection to a chassis or frame 8 15 Service Model 8640B Option 004 Table 8 4 Schematic Diagram Notes 2 of 3 Relay contact moves in direction of arrow when energized Indicates interlocked pushbutton switches Only one switch can be in ON at a time Indicates interconnected pushbutton switches Pushing one switch in ON releases the other Indicates twisted wire pair T indicates twisted wire triplet Indicates multiple paths represented by only one line Letters or names identify individual paths Numbers indicate number of paths represented by the line Coaxial or shielded cable RF coupling by magnetic H field SWITCH DESIGNATIONS EXAMPLE A3S1AR 2 1 2 A3S1 SWITCH S1 WITHIN ASSEMBLY A3 1ST WAFER FROM FRONT A 1ST ETC R REAR OF WAFER F FRONT 2 1 2 CONTACT LOCATION 2 1 2 VIEWED FROM FRONT
522. meter Frequency Tune 23 Flatwashers 4 18 Lockwasher A3MP24 Lockwashers 4 Potentiometer Bushing Spur Gear A2MP14 Retainer Ring 1 Retainer Ring 15 Setscrew MP58 RFI Gasket 8 Potentiometer Bushing 2 Retainer Ring 21 Setscrew 16 Spur Gear 19 Setscrew 20 Lockwasher 2 Potentiometer FM Gain Compensation A3MP22 Machine Screws 4 1 1 Machine Screws 8 1 14 Lockwasher 8 1 1 Buffer Board Cover 13 14 15 1 2 Machine Screw 1 Lockwasher 1 RFI Gasket 2 1 Counter Buffer Amplifier Assembly 11 Machine Screws 2 A3MP12 Lockwashers 2 10 Oscillator Fine Tune Assembly 5 RFI Gasket Transistor Cap A3MP13 RFI Plug RFI Plug 1 2 Filter Capacitor A8A1FL1 Filter Capacitor 1 2 RF Connector 1 10 Lockwasher 1 9 Hex Nut 1 1 RF Connector 1 12 Lockwasher AS3A1MP11 Hex Nut 4 1 Cable Clamp 4 Connector Board Assembly A38A4MP2 Machine Screw 1 15 Lockwasher 8 1 16 Setscrew 8 1 5 Buffer Board Cover A3A1MP6 RFI Gasket 2 ES 10 1 12 Figure 8 84 A3 RF Oscillator Illustrated Parts Breakdown 8 73 A3 Assembly Removal and Disassembly 4 SERVICE SHEET B Service SERVICE SHEET C A8 Assembly Re
523. mined by counter time base reference See the internal reference tests DESCRIPTION A frequency counter is used to measure frequency shift line voltage is changed 5 to 10 See Table 4 1 Recommended Test Abridgements VARIABLE VOLTAGE TRANSFORMER 9 0 0 0 99 AUX RF OUTPUT INPUT REAR PANEL PUT 509 Figure 4 3 Frequency Stability vs Line Voltage Test Setup EQUIPMENT Frequency Counter HP5327C Variable Voltage Transformer GR W5MT3A PROCEDURE 1 Connect equipment as shown in Figure 4 3 after setting Signal Generator s controls as follows follows FM OFF oioi oror r 1 32 64 MHz FREQUENCY TUNE 50 MHz ON OFF d 5 wo BON 2 Set variable voltage transformer 596 above the nominal voltage set on generator s line power module e g if nominal line voltage is 120 Vat set transformer for 126 Vat Note frequency counter reading 3 Set variable voltage transformer 10 below nominal line voltage e g for a nominal 120 Vat set transformer for 108 Vat then note counter s reading The frequency change from the reading noted in step 2 should be 50 Hz i e 1 ppm 50 Hz 4 19 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 18 FREQUENCY STABILITY VS LOAD LEVEL AND MODE TEST SPECIFICATION Stability vs Load with any passive load change lt 1 ppm Stability vs Level Change
524. moval and Disassembly Procedure 8 Casting Cover Removal 1 Place instrument right side up and remove top cover see Service Sheet G 2 Remove trim strip extrusion that overlaps front of A8 Assembly casting by removing two flat head screws Remove plastic front panel window by lifting it up and out 3 Remove three pan head screws on front of casting note length of screws and remove the button shield Remove eight pan head screws with lockwashers that secure casting cover to casting screws marked with asterisk on Cover 4 Lift cover from two honey comb RF shields and casting 8 2 and A8A4 Removal 5 Remove two pan head screws with lock washers that secure the A8A2 Assembly Remove A8A2 Counter Lock Board Assembly and A8A5 Riser Assembly by lifting at the riser the A8A4 Counter Display Assembly is attached to the A8A2 Assembly do not damage the brass LED button shield while removing the assemblies NOTE The 8 2 and 8 4 Assemblies can be extended for service by removing the A6A5 Riser Assembly from 8 2 and installing 8 2 on the extender board the riser socket ASA3XA8A5 This also gives access to the A8A3 Time Base Assembly CAUTION Do not remove A8A4 from A8A2 unless necessary If it has been removed exercise care during reassembly to avoid bending the connector pins and sockets 8 74 Model 8640B Option 004 8 Access WARNING The edges of the RF 1 gasket may
525. n For example if 64 128 MHz band s second harmonic is too high then R13 R12 and R14 will have to be changed Change attenuation in 1 dB steps e g to change their attenuation to 5 dB change R12 to 81 60 R13 to 1780 and R14 to 1789 NOTE Attenuation should be no higher than necessary to bring a band s second har monic within specification Excessive attenuation may reduce maximum RF output level Model 8640B Option 004 A26A3C3 C4 C5 and C6 Selection Capacitors may or may not be used their values are always 0 22 pF select as follows 1 Set AM switch to PULSE FREQIJENCY RANGE to 256 512 MHz and RF ON OFF to ON 2 Connect a spectrum to TO FLT 26 3 Check from 256 to 512 MHz tune FREQUENCY TUNE across band Sig nals should always be below 58 dBm 4 Add or remove capacitors across diodes as necessary to keep signals below 58 dBm 5 22 POST REPAIR TESTS AND ADJUSTMENTS 5 23 The adjustment in this section should be performed when the troubleshooting information in Section VIII Indicates that an adjustable circuit Adjustments is not operating correctly Perform the adjustments after repairing or replacing the circuit The re quired adjustments are specified in Table 5 2 Allow the instrument to warmup one hour before making any adjustment 5 24 After making the adjustments perform the performance tests found in Section IV specified i
526. n 004 Adjustments ADJUSTMENTS 5 37 RF OSCILLATOR END STOP ADJUSTMENT Cent d 8 Tune further ccw until second setscrew appears 9 Loosen setscrew and rotate FREQUENCY TUNE up or down by the amount of correction needed as noted in step 6 and tighten setscrew Do not allow front adjustment collar to rotate 10 Recheck high stop frequency and repeat preceding step as needed until stop frequency is correct Then secure both setscrews NOTE If the preceding steps have no effect check that the and FM Gain Compensation pots do not reach their stops first If so loosen the gear on the pot shaft and continue 11 Adjust FREQUENCY TUNE fully ccw The frequency should read between 0 4475 and 0 4482 MHz If it does not note how far off the frequency is 12 Adjust FREQUENCY TUNE cw until first setscrew cm adjustable stop ring appears Loosen setscrew 13 Tune further cw until second setscrew appears 14 Loosen setscrew and rot ate FREQUENCY TUNE up or down by the amount of correction needed as noted in step 11 and tighten setscrew Do not allow adjustable stop ring to rotate 15 Recheck low stop frequency and repeat preceding step as needed until stop frequency is correct Them secure both setscrews CAUTION Do not overtighten setscrews This may crack the adjustable end stop NOTE If the preceding steps have no effect check that the Vr and FM Gain Compensation pots do not reach their stops first If so loose
527. n is driven by a dc brushless motor controlled by the Fan Driver circuits TROUBLESHOOTING It is assumed that a problem has been isolated to the FM circuits and RF oscillator as a result of using the overall block diagram Troubleshoot by using the test equipment and procedures specified below Test Equipment Digital Voltmeter HP 3480D 3484A Option 043 Oscilloscope HP 180A 1801A 1820C Initial Test Conditions Top and bottom covers removed see Service Sheet G Procedure Set the generator s controls as listed in the box at the right hand side of the diagram To check a voltage at a test point change the control settings as specified in the box associated with that test point check the voltage then reset the controls to Model 8640B Option 004 SERVICE SHEET 2 Cont d the settings specified in the box at the right hand side The blocks are keyed by the numbers located in their lower right hand comers to the Service Sheets that have the circuit schematics NOTE The last two foldouts in this manual have top and bottom internal views of the instrument that show the locations of the test points assemblies and cables all RF cables are accessible from the bottom of the instrument NOTE After repairs are complete see Table 5 2 for appropriate post repair tests and ad justments AMPLIFIERS FM 38 MODULATION FREQUENCY 2 AUDIO OUTPUT LEVEL 0 1v
528. n oscillator set FM to INT Set MODULATION FREQUENCY e to the desired frequency and set the peak deviation with the PEAK DEVIATION switch and vernier D Figure 3 7 Setting the Modulation Controls 3 of 5 3 18 Modei 8640B Option 004 Operation SETTING MODULATION NOTE The REDUCE PEAK DEVIATION annunciator o lights whenever the PEAK DEVIATION switch setting is too high for the selected frequency range When it lights reduce PEAK DEVIATION Peak frequency deviation is indicated by the meter the meter is read conjunction with the PEAK DEVIATION switch e g with PEAK DEVIATION set to 320 kHz a meter reading of 2 8 indicates that peak frequency deviation is 280 kHz With FM set to INT the internal modulation oscillator signal is present at the OUTPUT jack 600 ohm source impedance Its level is set by AUDIO OUTPUT LEVEL To use an external modulation signal set FM o to AC or DC if modulation signal is less than 20 Hz Apply the signal to the FM INPUT jack 600 ohm load impedance The Signal Generator requires 1 Vpk 0 7071 Vrms for full peak deviation The PEAK DEVIATION controls and the meter o are used the same as when using the internal modulation oscillator signal To calibrate the external input set the FM switch o to DC with no signal applied to FM input and read the frequency of the RF Output Set FM to CAL and using the PEAK DEVIATION switch and vernier offset the freq
529. n some D flip flops 8 49 Schmitt Trigger A typical Schmitt Trigger is shown in Figure 8 7 Some Schmitt triggers have complementary outputs The device initially trig gers when the input signal passes a voltage refer Service ence called the upper trip point It triggers back into its initial state when the input voltage passes a voltage reference called the lower trip point One or both trip points may be indicated D FLIP FLOP BEFORE AFTER TRIGGER TRIGGER D INPUT Q OUTPUT Q Figure 8 6 D Flip Flop SCHMITT TRIGGER zl of wu UPPER TRIP POINT UTP LOWER TRIP POINT LTP OUTPUTS Figure 8 7 Schmitt Trigger 8 50 J K Flip Flop Figure 8 8 shows a typical J K flip flop The trigger T input is activated by a low going signal as indicated by the circle on the symbol Flip flop response is determined by the values of the J and K inputs at the instant that a low going signal is applied to the trigger input a When J and K are low the Q outputs will not change state 8 7 Service b When K is high and J is low Q will go low unless it is already low c When K is low and J is high Q will go high unless it is already high d When K and J are both high the flip flop will toggle That is if Q is high the trigger pulse will set Q low and if Q is low the trigger pulse will set Q high If K and J are connected together the J K flip flop produces a divide by two output
530. n the gear on the pot shaft and continue 16 Recheck both stop frequencies 17 If either the Vror FM Gain Compensation pots were altered perform either the VT Pot A3RI Adjustment 5 35 or Preliminary FM Adjustment 5 40 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 38 RF OSCILLATOR OUTPUT POWER ADJUSTMENT REFERENCE Service Sheet 5 DESCRIPTION The RF Oscillator output will require adjusting if the power level varies beyond the limits 0 5 to 4 5 dBm at the Divider Filter Buffer Amplifier or 12 to 2 dBm at the Frequency Counter Buffer Amplifier The power level is adjusted by changing the input loop penetration of the appropriate buffer amplifier in the oscillator cavity 86408 OPTION 004 SPECTRUM ANALYZER POWER METER STEPS A3A1J1 A3A1J2 POWER SENSOR STEP Figure 5 7 RF Oscillator Output Power Adjustment Test Setup EQUIPMENT Power Meter HP 435A Power Sensor HP 8482A Spectrum Analyzer HP 141T 8552B 8554B PROCEDURE l Remove A3 RF Oscillator from chassis Refer to Service Sheet B for removal procedure 2 Remove cover from the appropriate buffer amplifier assembly 3 Re insert A3A4 Connector Board Assembly into place while keeping oscillator section free of chassis It may be necessary to unsnap the clip on the rear of the oscillator housing to free the wiring harnes
531. n the table In general if any casting was opened or any RF connectors removed during a repair the Output Leakage Test should be performed Performance tests should also be made for any assembly that had a component changed even if that changed component was not defective The power supplies should be checked whenever an assembly has been repaired NOTE Table 5 2 can also be used for trouble shooting If the generator failed one or more performance tests cross referencing to the associated assembly or circuitry will often indicate the source of the failure Table 5 1 Factory Selected Components Service Sheet Range of Values Basis of Selection A8AIC8 8 1 4 2 2 See_paragraph 5 21 See paragraph 5 21 Select for an indication on counter with 100 mVrms applied to COUNTER INPUT 240 310 See paragraph 5 21 A10A2R3 51 10 75 00 Seel paragraph 5 21 paragraph 5 21 A10A2R6 8 R12 14 and R18 20 215 to 316 Ohms A11R28 Option 001 A26A3C3 C4 C5 C6 See paragraph 5 21 Seel paragraph 5 27 Select for less than specified distortion with dis tortion analyzer connected to front panel out put jack Distortion should not be so low that amplitude stability is poor at 20 Hz See paragraph 5 21 Adjustments Model 8640B Option 004 Table 5 2 Post Repair Tests and Adjustments 1 of 4 Assembly Repaired Performance Tests Adjustments Al 1 dB Output Level Assy O
532. nce Tests PERFORMANCE TESTS 4 25 OUTPUT LEVEL ACCURACY TEST Abbreviated Cent d EQUIPMENT Spectrum Analyzer HP dE oen Power Meter 435A Power Sensor 2 0 5 55 HP 8482A 20 dB Amplifier 2 required HP 8447 10dB Step Attenuator 2 s 5 HP355D Double Shielded Cable 2 required 2 HP 08708 6033 PROCEDURE 1 Connect equipment as shown in Figure 4 10 after setting Signal Generator s controls as follows Meter Function LEVEL COUNTER MODE EXPAND off LOCK a x e Off Source 4 4 4 X c X X X e x ow a INT FM X we de gH OFF RANGE 256 512 MHZ FREQUENCY TUNE s 512MBz OUTPUT LEVEL Switches 15 dBm OUTPUT LEVEL Vernier CAL RF ON OFF a amp 22 amp ss dares ON 2 Set power meter s controls so that it can measure 15 dBm Connect power sensor to Signal Generator s RF OUT 3 Set Signal Generator s RF OUTPUT LEVEL controls and vernier for levels set using generator s panel meter shown in the table below verify that the level is within the specified tolerance 435 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 25 OUTPUT LEVEL ACCURACY TEST Abbreviated Cent d Signal Generator Power Meter Output Level RF Level Set Reading dBm 10 dB with Panel Meter Fully cw 15 dBm 14 dBm 13 dBm 12
533. nctional Check only Refer to the Mac in Appendix D for Army test equipment requirements NOTE The safety classification of this instru ment is Safety Class I It has been designed and tested according to IEC Publication 348 SAFETY REQUIRE MENTS FOR ELECTRONIC MEASUR ING APPARATUS and has been sup plied in safe condition The instruction manual contains in formation warnings and cautions which must be followed by the user to ensure safe operation and to retain the instrument in safe condition 1 7 General Information Model 8640B Option 004 Table 1 1 Specifications 1 of 6 All specifications apply over the nominal Frequency Bands unless otherwise specified FREQUENCY CHARACTERISTICS Range 500 kHz to 512 MHz in 10 Octave Bands to 1024 MHz with External Frequency Doubler Bands and Band Overlap Bands extend 10 below and 7 above the nominal Frequency Bands shown below Frequency Range MHz Frequency Bands MHz with overlap 0 45 1 07 0 9 2 1 1 8 4 2 3 6 8 5 71 2 17 1 14 4 34 3 28 8 68 7 57 5 137 5 115 275 230 550 128 256 256 512 External Doubler Band 512 1024 460 1100 Internal Counter Resolution Frequency Bands Normal Expand MHz Mode X100 0 5 1 1 16 16 128 128 1024 1 Accuracy 6 digit LED display with X10 100 pand accuracy depends on internal or external refer ence used Total Counter Reference Count
534. ncy interference round head right resistance inductance capacitance rack mount only root mean square round read only memory rack and panel reverse working voltage Scattering parameter second time second plane angle slow blow fuse used in parts list silicon controlled rectifier screw selenium sections semicon superhigh fre quency silicon signal to noise ratio single pole double throw spring split ring single pole single throw single sideband stainless steel standing wave ratio synchronize timed slow blow fuse tantalum temperature compensating All abbreviations in the parts list will be in upper case MULTIPLIERS Abbreviation Prefix tera giga mega kilo deka deci centi milli micro nano pico femto atto Multiple 1012 109 time delay terminal thread through titanium tolerance trimmer transistor transistor transistor television television interference traveling waye tube micro 109 used in parts list microfarad used in parts list ultrahigh frequency unregulated volt voltampere volts ac variable voltage controlled oscillator volts dc volts dc working used in parts list volts filtered variable frequency oscillator very high fre quency volts peak volts peak to peak volts rms voltage standing wave ratio voltage tuned oscillator vacuum tube voltmeter volts switched working in
535. nel OUTPUT ports The variable frequency modulation oscillator shown on this Service Sheet is supplied with Option 001 Modulation Oscillator Al 1 The Modulation Oscillator is a Wein bridge type Transistors Q7 to Q12 form a differential amplifier The gate of FET QIll is a high impedance non inverting input of the amplifier Transistor 12 is an emitter follower buffer amplifier Trimmer capacitor C9 compensates for the high frequency phase shift of the amplifier Transistors Q9 and 10 provide voltage gain and drive the complementary symmetry output transistors Q7 and Q8 The inverting input to the amplifier is the emitter of Q9 Diodes CR2 to CR4 bias and thermally compensate Q7 and Q8 Components R19 Cll and C12 frequency compensate the amplifier Resistor R26 provides negative dc feedback A frequency selective Wein ladder forms a positive feedback path This network is a band pass filter with zero phase shift at the maximum of the pass band The frequency of oscillation is determined by the resistors and capacitors of the ladder In the FIXED FREQ range C6 and C7 are the ladder capacitors and either R2 and R6 or R3 and R5 in parallel with R6 are the resistors In the variable frequency ranges and are the variable ladder capacitors and R1 and R4 each in parallel with one or none of the resistors on the 1 Frequency Select Switch are the resistors Capacitors C2 C3 C4 and C5 set the frequency end points and max
536. ng four screws Slide cover to the rear approximately two inches to disengage it from flanges at the instrument s front and rear Lift it off Remove bottom cover by removing four screws Slide cover to the rear approximately two inches to disengage it from flanges at the instruments front and rear Lift it off Circuit Board Removal 3 Remove any plug in circuit board by gently lifting the bead s extractors the extractors are color keyed to the guides at the board s edges M1 Removal 1 Remove top cover 2 Remove trim strip extrusion that overlaps panel meter by removing two flat head screws Remove plastic front panel window by lifting it up and out 8 82 Model 8640B Option 004 Remove A4 Meter Annunciator Drive Assembly Remove four pan head screws with lock washers that secure A8 Counter Lock Assem bly to chassis Remove A6 Annunciator Assembly by first disconnecting plug A6P1 and removing two flat head screws on front face of meter bezel Then lift left edge of A8 Assembly and move A6 Assembly to the rear To remove meter disconnect two wires at rear of meter black wire from negative post white wire to positive post Push top edge of meter to the rear and lift meter from chassis NOTE If necessary loosen A 11 Modulation Oscillator to provide clearance for meter see Service Sheet D To install meter reverse procedure given in steps one through seven To install Annuncia tor Assem
537. ng on the meter The Scale Annunciator Lamp Control section of the switch lights the proper scale annunciator lamp on A6 for a given peak deviation range when the meter mode selected is FM TROUBLESHOOTING It is assumed that a problem has been isolated to the over deviation detector meter attenuator or scale annunciator lamp control circuits as a result of using the troubleshooting block diagrams Test Equipment Digital Voltmeter wie a uu ER eR UE CR EVE os da HP3480D 3484A Oscilloscope od cecus Say ot d Hp 180A 1801A 1820C Initial Test Conditions Bottom cover removed see Service Sheet G for removal procedure Extend A7 FM Shaping Assembly on extender board Connect AM OUTPUT to FM INPUT Initial Control Settings INT AUDIO OUTPUT MODULATION I d cll cde dr Oe aw tg A ccw MODULATION FREQUENCY 400 Hz Fixed EN E Gina ce PA AN C PEAK DEVIATION Vernier 2 2 2 25 2 25 25 CW RANGE Sa oh Scots mieu cd rad So ut SENT JC dr ah tout rore he ho o orae EP Dt 0 5 1MHz SERVICE SHEET 8 Cent d Over Deviation and Meter Control Circuits Troubleshooting Component Test Conditions and If Indication VER Initial conditions REDUCE FM Replace faulty DEVON and settings Ad VERNIER lamp component DETECTOR just PEAK DEVI unlit and 7 ATION vernier for 1 pins 6 8 10 1 8 Vp p at
538. nge in the spectrum analyzer s display when connected to the RF filters b Adjust analyzer s center frequency controls for a frequency counter indication of the pass band frequency listed in the table Adjust analyzer s vertical sensitivity controls to set trace to top reference graticule line on display use 2 dB log per division this sets the reference level for the filter check c Set analyzer s frequency span controls as listed in the table Connect test cables to RF filter input and output as shown in the test setup Check maximum loss at pass band frequency center vertical graticule line and below it should be as specified d Set analyzer s frequency span controls to zero Hz Adjust analyzer s center frequency controls for a frequency counter indication of the stop band frequency listed in the table Then reset frequency span controls as listed in the table and set analyzer s display for 10 dB log per division NOTE To measure the stop band frequency on the highest band it is necessary to set a frequency of 492 MHz at the second vertical graticule line to the left of center This puts 692 MHz at the center the counter will only read to 550 MHz e Check minimum loss at stop band frequency center vertical graticule line and above it should be as specified f If necessary on the 64 512 MHz bands adjust the appropriate filter components to set pass band and stop band insertion loss within the specified limits Use a non
539. nitial test conditions and following the procedures outlined in the text and the table SERVICE SHEET 22 Cont d Test Equipment Digital Voltmeter 3480D 3484 A Oscilloscope HP 180A 1801A 1820C Initial Test Conditions Top cover removed see Service Sheet G for removal procedure Use extender board to extend desired assembly set instrument LINE power switch to OFF while removing or inserting circuit boards Initial Control Settings LINE ON Rectifiers and Input Crowbar A12 If the Input Crowbar fires causing the line fuse to blow check the following 1 Voltage Selection Card P1 in A14 Line Power Assembly correctly set for line voltage 2 All rectifier diodes and filter capacitors 3 Q1 and associated components Input Crowbar f one or two rectifier diodes in one of the bridge rectifiers are lefective ripple and noise could increase without affecting the supply s average voltage or output current Use the oscilloscope to measure ripple and noise connect the probe from the test points given below to chassis ground Typical Ripple and Noise Tast Point A20TP1 lt 0 7 Vp p A22TP1 lt 0 5 Vp p A20TP6 lt 1 Vp p A22TP6 0 3 Vp p 18 1 lt 0 8 Vp p If one of the supplies is out of specification check the rectifier diodes filler capacitors and associated components Also check the Series Regulator transistor If noise
540. nly if al previous counters are zero their borrows having rippled through to enable it Counter Operation Transition from Counter Mode to Phase Lock Mode A8A2 When COUNTER MODE LOCK switch 81 is depressed to ON the counter sequences as follows Counters U19 to U24 continue counting up until TIME BASE goes low Stall Counter U28 has been preset to the count of eight Storage Buffers U7 through U12 are loaded with the outputs of the counters and then latched then the counters are cleared and the input to the main counter is inhibited while the input to the Stall Counter is enabled The lock mode is now entered with LOCK high and the Qp output of stall counter U28 high The D input of U1B is high and the next clock input toggles the Q output to a low The clock to the main counter is then enabled and that to the Stall Counter disabled The next input pulse sends the main counter to 999 999 since it was previously cleared to zero The counter now sequences in the normal phase lock mode Flash Oscillator ABA2 When a phase lock error is detected a 2 Hz flash oscillator is turned on to blink the display Transistors Q5 and Q4 form a two stage astable multivibrator A high on the ERROR line holds collector resistor R42 at about 3V and the oscillator is biased on The frequency of oscillation is determined by the time constants of R39 C9 and R41 C8 The collector of Q4 switches transistor Q3 which switches the Vec supply to the Storage
541. notify the carrier as well as the Hewlett Packard office Keep the shipping materials for carrier s inspection The HP office will arrange for repair or replacement with out waiting for claim settlement 2 5 PREPARATION FOR USE 2 6 Power Requirements 2 7 The Model 8640B Option 004 requires a power source of 100 120 220 or 240 Vac 5 10 48 to 440 Hz single phase Power cohsump tion is 175 VA maximum PC BOARD HP 5020 8122 SELECTION OF OPERATING VOLTAGE 1 Open cover door and rotate fuse pull to left 2 Select operating voltaga by orienting PC board to position desired voltage on top left side Push board firmly into module slot 3 Rotate fuse pull back into normal position and re insert fuss in holders using cautions to select correct fuse value Figure 2 1 Line Selector Installation 2 8 Line Voltage Selection CAUTION To prevent damage to the instrument make the line voltage selection BEFORE connecting the line power Also ensure the line power cord is connected to a line power socket that is provided with a protective earth contact 2 9 A rear panel line power module permits operation from 100 120 220 or 240 Vat The number visible in the window located on the module indicates the nominal line voltage to which the instrument must be connected 2 10 To prepare the instrument for operation slide the fuse compartment cover to the left the line power cable must be disconnec
542. o 9 in 8421 code The term binary when applied to four bit binary circuits refers to circuits that range from decimal O to 15 in 8421 code 8 43 Trigger T inputs are usually high going edge sensitive unless there is a circle at the input which would make them low going All other inputs are usually level sensitive 8 44 Open Collector TTL Some TTL gates have open collector outputs This feature is indicated by a note on the Service Sheet In open collector logic the output stage is an NPN transistor with the emit ter grounded and the collector connected directly to the output terminal with no internal pull up re sistor or transistor as shown ih Figure 814 The out put is low when the output transistor is saturated and is high when the transistor is off However the output can only be high when the collector is con nected to the positive supply through an external pull up resistor Open collector gates are often used to switch in non TTL devices such as lamps relays and capacitors Model 8640B Option 004 Table 8 2 Logic Levels Logic Voltage Levels High 1 2V Low 0 0 8V more negative than more positive than Input Conditioning TTL ECL EECL Grounded Low 0 High 1 High 1 Open High 1 Low 0 Low 0 Ground OV Figure 8 3 Open Collector Output Stage AND Gate BINARY SYMBOLS EXCLUSIVE OR Figure 8 4 Binary Symbols 8 6 Model 8640B Option 004
543. o stage differential input applifier The dual transistors Q1 and Q2 are connected in a Darlington configuration to provide matched high impedance inputs Amplifier offset adjustment R8 adjusts the dc offset The gain of the first stage is approximately one half the ratio R4 R3 gain for the second stage is approximately one half the ratio R5 R6 Transistors Q5 through Q8 form an intermediate driver stage The voltage gain of the stage is approximately twice the ratio of the impedance across R27 to that of R17 The shaping circuits require more gain for large positive voltage excursions For low positive voltages the resistor network R29 to R34 is in parallel with R27 As the voltage increases diodes CR10 11 and 12 respectively switch off and increase the impedance across R27 and thereby increase the amplifier s gain Transistors Q9 through Q12 form the amplifier output stage Transistors Q9 and Q10 are in a Darlington configuration and supply current to the load during positive excursions Transistors Q11 and Q12 are in an inverted Darlington configuration and sink load current during negative excursions SERVICE SHEET 6 Cent d Amplifier Configurations The FM Amplifier is switched by the A9 Peak Deviation and Range Switch into three different configurations depending on the gain needed For gains less than 0 dB the amplifier is in a unity gain configuration followed by the positive shaping network Service Sheet 7 which has little effe
544. o this is to unsolder and lift pins on the extender board However under some failure conditions the regulator integrated circuit can regulate correctly with the load removed from the power supply and yet cannot regulate correctly when the supply has its correct load To isolate a power supply problem to a specific circuit use the data given in the table NOTE The voltmeter input must float i e both connectors must be ungrounded when checking voltages with extender board pins open Fan Driver and Speed Regulator 8 If one or two of the fan s windings are open or are not being supplied with the correct voltage the fan may not start in all positions However once started it may run correctly Use the data given in the table to isolate a problem to a specific circuit Also check that the fan blade does not hit against the rear vent If it does loosen the setscrew and slide the blade forward Power Supply Circuits A12 A14 A20 A22 SERVICE SHEET 22 Service SERVICE SHEET 23 Cont d 5 2 REGULA TOR FAN DRIVER 8 64 Regulator and Fan Driver Troubleshooting Component Test Conditions and PON If Indication Remove A18 assy Measure resistance from A17XA18 6 14 to chassis ground Open pins 15 and 16 on ex tender board Extend Al 8 assy and check voltage from A18 board pin 15 to 18 5 Check diodes and transistors for correct operation with voltage applied Check com ponents for correct re
545. oard Assembly removed and extended for service see Service Sheet C for procedure Initial Control Settings COUNTER MODE EXPAND LOCK Off Source EXT O 10 TIME BASE INT EXT on rear panel 2 INT NOTE If phase lock is broken when the TIME BASE VERN control is turned with COUN T ER MODE set to INT LOCK and EXP X10 check Q16 Q17 and associated circuitry This will probably happen when RANGE is set to 8 16 MHz Up Down Counter and Display A8A2 A8A4 SERVICE SHEET 20 SERVICE SHEET 21 Cont d Component or Circuit COUNTER PHASE LOCK CIRCUITS A8A2 ERROR DETECTOR A8A2 LOCK EXPAND SWITCHING A8A2 Counter Phase Lock Circuits Troubleshooting Test Conditions and Control Settings Normal Indication Model 50405 Option If Indication is Abnormal Initial conditions and settings Perform the following steps in sequence 1 Ground TP4 to disable error signal 2 Set COUNTER MODE LOCK to ON 3 Set TIME BASE INT EXT to EXT with no input this sets time base line high Connect DVM to TP6 phase lock tune line and use a grounding probe to momen tarily ground the following points a Ground U14A pin 1 clears 1726 b Ground U26B pin 11 T TP6 at any voltage from 5 to 17V and stable TP6 voltage should rise within a few seconds to s 17V and U26B pin 8 Q should be low U29 A pin 1 should be 20
546. odel 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 38 DEMODULATED OUTPUT ACCURACY TEST Cent d 8 10 12 Perform steps and to obtain value of offset voltage to be used in step 12 a For steps 6 and 7 derive values of a expressed as a ratio from the formula a 10A Attenuation dB 20 and where Attenuation is the attenuation of step 3 minus that of step 6 or step 7 Attenuation figures should be obtained from the step attenuator s calibration chart which is accurate to 0 02 dB at 3 MHz e g 3 16 10 dB for step 6 and a 0 316 10 dB for step 7 a Step 6 a step 7 For steps 6 and 7 derive values of offset voltage Voff from the formula mVdc 200a g l a where mVdc is the digital voltmeter reading of step 6 or 7 and where a is the value derived in step 8a Voff step 6 Voff step 7 Calculate the average of the two values of offset voltage and use this Voff in step 12 the difference between the two values of offset voltage should be lt 2 mVdc Voff Set the Signal Generator RANGE to 64 128 MHz and FREQUENCY TUNE to 113 MHz Set the calibrated step attenuator to 10 dB Set the spectrum analyzer to display the 113 MHz signal with zero frequency span and peak the trace Set AM to DC Set the test oscillator frequency to 120 Hz and adjust the level to give approximately 20 AM as read on the Signal Generator panel meter
547. of a nine count sequence the load LD input is enabled The next count input presets the counter to the binary count at the data inputs D 4 Dp De and Dj The counter then counts the clock input pulses beginning at the preset count When the count reaches nine ihe counter generates a high carry The carry pulse enables the load input via inverter and on the next clock pulse presets the counter The count sequence is then repeated The total count equals 10 preset count The preset count is also determined by the RANGE switch and COUNTER MODE switches The band code lines CODE 1 CODE 2 CODE and CODE 8 and the COUNTER MODE functions are decoded by gates U1C U4A U4B U6D and U9 which drive the data inputs of U15 The data inputs of U15 for different count conditions are given dane SEES that band CODE 4 is defined as all highs on CODE 1 CODE 2 CODE 5 and CODE 8 When counter U15 is preset for 1 the carry output remains high and the output of remains low OR gate USB now reproduces the output of inverter UTF directly Expand Decoder A8A3 The Expand Decoder counters 016 and 017 are programmed to divide the Time Base Reference Decoder output by one nor mally by ten in EXPAND X10 or by 100 in EXPAND X100 The counters are configured as 10 counters with output Q4 connected to input Tpp When the reset to nine input Rg at pin 7 SERVICE SHEET 19 Cont d is low the counter oper
548. ollowing changes to the A26A2 assembly Change 35 to 4220 Add R40 19 6K between the collector of Q9 and ground CHANGE 9 Page 6 25 Table 6 3 Change A11C24 to 0160 2199 CAPACITOR FXD 30 pF 5 300 WVDC Service Sheet 9A schematic Change A11C24 to 30 pF CHANGE 10 Table 6 3 Add A8MP47 08640 00100 INSULATOR RF SCALER Add A8MP48 08640 00102 INSULATOR COUNTER TIME BASE Page 6 23 Table 6 3 Change A10A2R58 to 0698 3243 RESISTOR FXD 178K 1 0 125 W F TUBULAR Service Sheet 11 schematic Change resistor 104 2 58 to 178K CHANGE 11 thru 5 16 paragraph 5 30 Under REFERENCE delete service sheet 16 Under DESCRIPTION delete all except the first sentence and Note 1 In Figure 5 2 delete 10 dB step attenuator 20 dB amplifier and double shielded cables Under EQUIPMENT delete the spectrum analyzer 20 dB amplifier and double shielded cables Under PROCEDURE delete steps 4 thru 11 Page 6 4 Table 6 3 Change part number for A3Q1 to 5086 4282 see note Page 6 3 Table 6 3 Delete A19A2R7 and R8 Service Sheet 5 schematic Change part number for to 5086 4282 NOTE Transistor 5086 4282 is the recommended replacement for in instruments with serial number prefixes below 1535A also Model 8640B Option 004 08640 90973 CHANGE 11 Cont d Service Sheet 16 Principles of Operation Under Meter Attenuator and Odd Range Code Al Al 9A2 delete the fourth sentence Ser
549. oltage regulators A20U1 and U2 and A22UI and U2 to 1826 0010 Replace appropriate portions of schematic with attached partial schematics NOTE See paragraphs 7 30 and 7 32 for recommended instrument modifications 7 12 Model 8640B Option 004 CHANGE I Cont d wi TO LINE POWER K nore 2 p Ho pem dy Samer alee Manual Changes MANUAL CHANGES AMLINEPOWR CI 0502 X ERR ASSEMBLY 5060 9409 8 85 69 D E F E 100 A EAF EA ww E T B mw 4 7 7 Oe Figure 7 7 Power Supply Circuits Backdating Change I Manual Changes Model 8640B Option 004 MANUAL CHANGES CHANGE 1 Cont d P O A22 20V AND 20V REGULATOR ASSEMBLY 08640 60006 20V REGULATOR EQ 1854 0039 0 e j in 1 18 R6 C3 RI VOLTAGE T zd 4220 75600 200 Ele 3 LN Lcl ioo TT ur T 4920 10K CR1 2150 2 Figure 7 8 A22 20V and 20V Regulator Assembly Backdating Change I Service Sheet 23 schematic Change part number for A18UI to 1826 0010 NOTE paragraph 7 32 for recommended instrument modification CHANGE J Page 6 19 Table 6 3 Change A101C17 and C52 to 0140 0150 CAPACITOR FXD 731 5 PF 1 300 WVDC Service Sheet 10 schematic Change A101C17 and C52 to 731 5 pF CHANGE K and 6 8 Table 6 3 Change A3AARI to 2100 3161 RESISTOR VAR TRMR 20K
550. ometric mean switching does not take place and the FREQUENCY TUNE control can be left at any position 5 32 Model 8640B Option 004 Adjustments ADJUSTMENTS 5 39 RF FILTER ADJUSTMENT Cont d So aa E A10A1 Ee C81 C82 C83 C84 SILVERED AREA Figure 5 10 256 512 MHz High Band Capacitor Adjustment Orientation 540 PRELIMINARY FM ADJUSTMENTS REFERENCE Service Sheets 6 and 7 DESCRIPTION A digital voltmeter is used to correctly set the mechanical position of the FM compensation pot on the RF oscillator this is necessary only if either the oscillator or the pot has been changed Then the DVM is used to adjust the FM calibration voltage and the offset balance voltages in the FM amplifiers EQUIPMENT Digital Voltmeter HP 3480D 3484A Option 042 PROCEDURE 1 Set Signal Generator s controls as follows Meter Function 2564 42620 FM COUNTER MODE EXPAND Off LOCK o Off Source Eom eA Qs INE AM 2 B mE OX Sox zx vB MA 22 0 OFF FM OFF PEAK DEVIATION i 4 be 2 56 MHz PEAK DEVIATION Vernier je ede Gh BS Ux 0 Fully ew RANGE 2 s s s 256 512 MHz FREQUENCY TUNE 5 Fully RF ON OFF ON 5 33 Adjustments Model 8640B Option 004 5 40 2 10 5 34 ADJUSTMENTS PRELIMINARY FM ADJUSTMENTS Cont d To set the compensation pot A3R2 turn generator s LINE switch to OFF Loosen setscrews in
551. on VI 8 22 Servicing Aids on Printed Circuit Boards The servicing aids include test points transistor and integrated circuit designations adjustment callouts and assembly stock numbers 8 23 REPAIR 8 24 Factory Selected Components 8 25 Some component values are selected at the time of final checkout at the factory see Table 5 1 Usually these values are not extremely criti cal they are selected to provide optimum compat ibility with associated components These com ponents are identified cm individual schematics by an asterisk The recommended procedure for replacing a factory selected part is as follows a Try the original value then perform the calibration test specified for the circuit in the performance and adjustment sections of this manual b If calibration cannot be accomplished try the typical value shown in the parts list and repeat the test c If the test results are still not satisfactory substitute various values within the tolerances specified in Table 5 1 until the desired result is obtained Service 8 26 Etched Circuits 8 27 The etched circuit boards in the Signal Generator are of the plated through type consisting of metallic conductors bonded to both sides of insulating material The metallic conductors are extended through the component mounting holes by a plating process Soldering can be done from either side of the board with equally good results lists recommendations and
552. on of the instrument Then turn to the troubleshooting block diagram that covers that section of the instrument and use the information on the diagram to isolate the trouble to the defective assembly Next turn to the Service Sheet that covers that assembly and isolate the trouble to the defective component or replace the assembly For example suppose the AM functions are out of specification The block diagram on Service Sheet 1 is keyed to the troubleshooting block diagrams Model 8640B Option 004 Service COUNTER LOCK CIRCUITS SERVICE SHEET 1 Cont d WARNING prs Source MET that follow it in this case Service Sheet 3 The opening of covers or removal of pr 0710 Service Sheet 3 gives a list of generator control parts except those to which access can COUNTER 27 edere pec i settings the list is located in the box the gained xd D is ead to 5 BUFFER STORAGE AND DISPLAY right hand side of the sheet and the voltages and ive parts and also accessible terminals E 258858 OC ume that should be found at the Ex points may be live Any adjustment mainten ar GEAAGE and along the signal paths To check a voltage at a ance and repair of the opened instru test point change the control settings as specified ment under voltage should be avoided as TIME BASE REF in the box associated with that test point check much as possible and if inevitable the voltage th
553. ontrols so that the 1 KHz signal has 8 divisions of peak to peak deflection i e 1 25 AM per division Set generator s AM switch to OFF and FM switch to INT Set Meter Function to FM and set PEAK DEVIATION vernier to 2 56 MHz Increase oscilloscope sensitivity by 10 Using generator s FREQUENCY TUNE control tune across the band and record the maximum incidental AM read on the oscilloscope It should be less than 1 8 divisions peak to peak on the display Maximum 1 Set PEAK DEVIATION switch to 320 kHz Again using the generators FREQUENCY TUNE control tune across the band Incidental AM should be less than 0 596 4 divisions peak to peak on the display 1 8 Maximum Deviation 1 0 5 NOTE Incidental AM is usually worse case on the 256 512 MHz band If desired it can be checked on any other band using this test except that on the 0 5 to 16 MHz bands the capacitor across the resistor at the detector s output must be changed to 0 033 uF HP 0160 0163 on the 16 to 512 MHz bands the 0 001 uF capacitor shown in the test setup must be used Model 8640B Option 004 PERFORMANCE TESTS 4 47 COUNTER EXTERNAL SENSITIVITY TEST SPECIFICATION External RF Input Frequency Range 1 Hz to 550 MHz Sensitivity 100 mWrms ac only into 50 2 dBm DESCRIPTION Performance Tests A test oscillator and the Signal Generator s own RF output are used to verify the counter s range and sensitivity
554. or Blak Stabe vs TREE rede meter mechanical part electrica connector movable portion plug transistor SCR triode thyristor transformer terminal board thermocouple test point ABBREVIATIONS coefficient ati ws common xe pd composition 55 gens complete Tm connector cadmium plate cathode ray tube complementary transistor logic continuous wave UEM clockwise T DUE centimeter x digital to analog decibel decibel referred to 1 mW n direct current degree temperature interval or differ ence degree plane PII A degree Celsius centigrade degree Fahrenheit K degree Kelvin DEPC deposited carbon ees UTE dh detector usce ert diameter diameter used in parts list DIFF AMPL o differential TER double pole double throw 2 Grive double sideband diode transistor logic digital voltmeter emitter coupled logic electromotive force NOTE electronic data processing IUE electrolytic encapsulated external farad fillister head frequency modulation front panel se sale frequency fixed ground ed LR ote henry hour x heterodyne T bee hexagonal ess hardware high frequency mercury 2 high Hewlett Packard high pass filter hour used in parta list high voltage er nn nsns Hertz integrated circuit 2
555. or serial number prefix 7 9 Improved FM Bandwidth on 5 kHz Deviation Range Serial Number Prefixes 1323A and 1327A 7 10 A slight peaking in FM deviation at approxi mately 200 kHz rates may be reduced by adding 9 8 selection of the proper value 7 11 AI0A2 RF Divider Assembly Improvement Serial Number Prefixes 1333A and Below 7 12 Spurious response and second harmonic level can be reduced by adding a 1000 pF capacitor HP 0160 3456 between the heat sink 5 2V line of A10A2U14 and ground Some RF Divider boards have holes to accommodate the new capacitor If the board does not solder the capacitor C54 directly to the heat sink lead 5 2V and to the ground plane 7 13 A18 A20 and A22 Power Supply Regulator Improvements Serial Number Prefixes 1333A and Below 7 14 Changing the power supply regulator driver transistors will reduce the possibility of oscillation If any of the power supplies oscillate change either A18Q2 A20Q2 or A22Q2 and Q3 to a new transistor HP 1854 0232 with a lower cutoff frequency 15 MHz as opposed to 200 MHz After completion of the modification perform the Power Supply Adjustments and the appropriate perform ance tests see Post Repair Tests and Adjustments table in Section V 7 15 Al 1 Variable Frequency Modulation Oscillator Improvements Serial Number Prefixes 1339A and Below 7 16 Distortion in the Variable Frequency Modul ation Oscillator Option 001
556. orners to the Service Sheets that have the circuit schematics NOTE The last two foldouts in this manual have top and bottom internal views of the instrument that show the locations of the test points assemblies and cables all RF cables are accessible from the bottom of the instrument NOTE After repairs are complete Table 5 2 for appropriate post repair tests and ad justments P O A8 COUNTER LOCK ASSY P O ABA3 TIME BASE ASSY A8A3 o LINT ur 000 000 5 Hz TTL SQUAREWAVE OUTPUT D L2 2 J0 COUNTER X MODE l i DIVIDE TIME BASE BY N DECODER REA DECIMAL POINT DECODER n TIME B SE TIME BASI EXT 0 10 sere N 1 ar Eres O NN o Base r 1 boo pum a TIMEBASE 1 5 UP DOWN COUNTER mme q wy l NOUT m Service P O A8 COUNTER LOCK ASSY SSS TED TT Kam ue SS SS 2 COUNTER LOCK BOARD ASSY ABA2 Ot 4 gt erase Lock TUNE NULL PHASE DETECTOR ON COUNTER LOAD COUNT DOWN ABA4 COUNTER DISPLAY ASSY ABA L DECIMAL POINTS OVERFLOW DETECTOR L TIME BASE VERN CCW QUT OF DETENT
557. other end fits another common size SMC connector which may be used in servicing the instrument 5 1 Adjustments 5 19 FACTORY SELECTED COMPONENTS 5 20 Table 5 1 contains a list of factory selected components by reference designation basis of selection and schematic diagram location Factory selected components are designated by an asterisk on the schematic diagrams i 5 21 The following information supplements Table 5 1 A8A1C8 Selection Capacitor may or may not be used its value will always be 2 2 pF Select as follows 1 Set COUNTER MODE Source to EXT 0 550 RANGE to 256 512 MHz and OUTPUT LEVEL controls to 10 dBm 2 Connect RF OUT to COUNTER INPUT 3 Turn FREQUENCY TUNE CW and ob serve frequency increase towards 550 MHz on the counter 4 Repeat step 3 for OUTPUT LEVEL settings of 0 dBm and 7 dBm If count becomes erratic or displays zero count as frequency approaches 550 MHz add capacitor between pins 13 and 16 of ASATUI b ASAIRA Selection If A8A1U5 has been replaced and counter external sensitivity is not within specification select 8 1 4 as follows l Set COUNTER MODE to EXT 0 10 or EXT 0 550 2 Measure dc voltage at A8A1U5 pins 1 and 14 3 Select a value of resistance that will bring dc voltage at pin 14 to within 10 of voltage at pin 1 A9C8 Selection If A9 has been perform 3 dB BANDWIDTH TEST 4 38 to determine if the FM Amplifier is peaking abo
558. oubler Band the auxiliary RF 0 Line Power Module permits operation from 100 output is one half the frequency of the indicated 120 220 or 240 Vac The number visible in RF frequency window indicates nominal line voltage to which instrument must be connected see Figure 2 1 TIME BASE Reference In Out input for ex Center conductor is safety earth ground ternal 5 MHz time base reference that is 2100 mVrms load impedance is 1 Output for intemal 5 MHz time base reference level is 2 Any interruption of the protective 3 Vrms into an open circuit source impedance is 4 an 500 ohms grounding conductor inside or out side the instrument or disconnection TIME BASE Reference INT EXT switch selects of the protective earth terminal is function of IN OUT jack INT position applies likely to make the instrument danger internal reference to jack EXT position feeds ous Intentiona interruption is pro external reference from jack to time base hibited See Se tion ii Serial Number Plate first four digits of serial NOTE number comprise the prefix which defines the instrument configuration last five digits form Since the phase lock reference is the sequential suffix that is unique to each instrument 5 MHz time base the Model 8640B The plate also indicates any options supplied with Option 004 can be phase locked to an instruments Figure 3 4 Rear Panel Controls and Connectors Operation Mode 8640B Option 004 OPE
559. oubleshoot by using the test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table Test Equipment Digital Voltmeter Oscilloscope HP 34801D 3484A Option 043 HP 180A 1801A 1820C Initial Test Conditions To test A26A4 AGC Amplifier Assembly remove top cover see Service Sheet G for removal procedure remove A26 AM AGC and RF Amplifier Assembly casting top cover and remove A26A4 and extend for service see Service Sheet F for procedure To test A26A3 Modulator Assembly and A26U2 Modulator Preamplifier remove bottom cover see Service Sheet G for removal procedure and remove A26 casting bottom cover see Service Sheet F for procedure Initial Control Settings COUNTER MODE EXPAND Off LOCK 2 00 Sess rsen ours Source s i s oe Ge wee gS Rem cei x4 ae dee INT MODULATION 2 2 2 2 2 2 2 100 96 Meter Function 2 2 2 LEVEL MODULATION FREQUENCY 1 kHz FM OFF RANGE 43 39 Ea hea Y eet 8 16 MHz FREQUENCY TUNE 7 20 MHz OUTPUT LEVEL Switches M 10 dBm 10 0 OUTPUT LEVEL Vernier RF ON RF Dividers A10A2 SERVICE SHEET 11 Service SERVICE SHEET 12 Cont d Component or Circuit Model 8640B Option 004 AGC Amplifi
560. ount the T4 input pulses of U11 When the count reaches 100 the output of U10 goes low and the Q4 output of U12B goes high the high pulse sets counters U11 and U10 to nine through the resistor capacitor network and USC reset to zero inputs at pin 2 are also held high through resistor capacitor network R11 and C23 and AND gate U4C but the reset to nine overrides the reset to zero The time constant of the reset to zero resistor capacitor network is longer than the reset to nine resistor capacitor network so counter U11 and 1710 first reset to nine then reset to zero and both happen between input pulses The low going Qr output of 1710 sets the output of U12B zero The count sequence now repeats The result of the sequence is that the output of U12B is low for nearly all of 100 counts and high for only a small fraction of one count dividing the frequency by 100 The output of the lock decoder drives inverter 17 whose output is the counter time base Decimal Point Decoder A8A3 The decimal point decoder decodes the band code and counter mode inputs and drives the decimal point lines to the display In the EXPAND X10 mode the decimal point is shifted to the left one place in the EXPAND X100 mode it is shifted two places Gates U1A U1B U8B 08 USD decode the decimal point location from the band code and counter mode inputs and drive the data inputs De and Dp of the decimal point shift re
561. overs removed see Service Sheet G for removal procedure Extend All Fixed Frequency Modulation Oscillator Assembly on extender board see Service Sheet C for removal procedure Initial Control Settings AM INT AUDIO OUTPUT LEVEL CW MODULATION FREQUENCY 400 Hz Fine Frequency Adjustment The oscillator s frequency can be lowered slightly by twisting the orange 3 yellow 4 and green 5 wires together The wires connect MODULATION FREQUENCY switch A11AISI to the All circuit board Fixed Frequency Modulation Oscillator Troubleshooting MODULATION OSCILLATOR Initial conditions and settings Then set MOD ASSY AID ULATION FREQUENCY to 1000 Hz Peak to peak voltages are as shown on schematic faulty component Check appropriate circuit and replace Model 8640B Option 004 Service REFERENCE DESIGNATIONS AI3 A1 FIXED FREQUENCY MODULATION OSCILLATOR ASSY 08640 60020 _ All 1 FREQUENCY SELECT SWITCH ASSY 08640 60116 UE umm AM OUTPUT BUFFER Se 1 P O 51 52 s 9 PIO PIO P O I 2 1 i NM 1 5 13 I Q3 1854 0071 Be B 1 e por Q4 er 0 Me ET g 07 9 8 DELETED 11 1 85 89 os zee See v MODULATION 14 d eA i FREQUENCY T P e l Os HG adde cde AA 7 i 1 BR RI R3 MP OO ALD
562. own in step e NOTE With RANGE set to 512 1024 MHz FREQUENCY will read approximately 0384 00 MHz the actual frequency at RF OUT Meter h Set OUTPUT LEVEL to 7 dBm 10 3 the meter should indicate approximately 5 on the 0 10 SCALE the 0 10 SCALE annunciator should light Reduce OUTPUT LEVEL to 14Bm 10 11 the meter should auto range to the 0 3 SCALE when the indicator passes approximately 3 on the 0 10 SCALE Figure 3 5 Operator s Checks 3 of 5 3 10 Model 8640B Option 004 Operation OPERATOR S CHECKS With OUTPUT LEVEL set to 1 dBm 10 11 the meter should indicate approximately 2 on the 0 3 SCALE Increase OUTPUT LEVEL to 7 dBm the meter should autorange to the 0 10 SCALE when the indicator passes approximately 3 on the 0 3 SCALE Amplitude Modulation k Set Meter Function e to AM and AM o to INT Slowly turn Modulation clockwise When the Meter indicates 10 i e 100 modulation set OUTPUT LEVEL to 16 dBm the REDUCE PEAK POWER annunciator should light Frequency Modulation L Set AM to OFF the annunciator should go out and FM to INT Set Meter Function to FM and check that PEAK DEVIATION is set to 5 kHz and the vernier is full counterclockwise the meter o should indicate 0 the PEAK DEVIATION vernier full clockwise the meter should indicate approximately 5 and the REDUCE FM VERNIER annunciator should light Redu
563. p and bottom internal views of the instrument that show the locations of the test points assemblies and cables all RF cables are accessible from the bottom of the instrument NOTE After repairs are complete see Table 5 2 for appropriate post repair test and ad justments Model 86408 Option 004 MODULATION FREOUENCY AUDIO OUTPUT LEVEL MODULATION FREQUENCY MODUL ATION Ww AM OUTPUT 00 TERMINATION _ 70 10 D S AT 400 Hz A13 MODULATION METERING MOTHER BOARD ASSY_ AT3 Or 1 m MOD PULSE AM INPUTS OUTPUT Dc D t 4c e C AUDIO 2 B INTS CODE 2 olo 1 1 olo mE plg Od Lao QUTPUT Aun e C MO A28 AMIAGC AND RF AMPLIFIER ASSY 713 01 0 6 dBm 413 0 0 8 dim 7175 t 12 kHz AT 7 2 MH P O Al 1 d8 A19 10 dB OUTPUT LEVEL out LEWEL OUTPUT n EM Q 2 A28 AM AGC AND RF AMPLIFIER ASSY P O DIVIDER FILTER ASSY eee ee 35 48 LESS A28 PAG A28A1 POWER AMPLIFIER AND AGC DETECTOR 55 THAN FILTER wt 2 I AI0A1 RF FILTER ASSY _____ _ _ mL M aaa AIGA MEN r z2 TUNE OUTPUT 1 AMPLIF
564. pacitor Bushing Insulator Nylon Numeric Display Lockwasher Mica Washer Center Filter Gasket Center Scaler Gasket Inductor LED Button Shield Center Filter Cover Large Frame RF Shield Small Frame RF Shield Center Input Cover Shield Heat Sink Counter Window P C Board Support Button Shield Top Casting Cover Bottom Casting Light Pipe Light Pipe Counter Display Assembly Time Base Assembly Counter Lock Assembly Counter Riser Board R F Scaler Assembly X10 Button X100 Button ON Button INT Button EXT Button Flat Washer Lockwasher Machine Screw Machine Screw Machine Screw Lockwasher Hex Nut Flat Head Screw Counter Insulator Machine Screw Machine Screw Lockwasher Machine Screw Machine Screw Machine Screw Blind Dome Rivet Service Figure 8 85 A8 Counter Lock Assembly Illustrated Parts Breakdown 8 75 A8 Assembly Removal and Disassembly SERVICE SHEET C Service SERVICE SHEET D A9 Assembly Removal Procedure 1 Set PEAK DEVIATION and RANGE switches fully counterclockwise 22 Remove PEAK DEVIATION and RANGE switch knobs The knobs are secured to their shafts with allen screws in the knobs 3 Place instrument upside down and remove bottom cover see Service Sheet G 4 Loosen coupling between RANGE switch shaft and A10 Divider Filter Assembly 5 Remove two nuts and lockwashers that secure 9 Assembly to front panel located at switch bush
565. paired and tested assemblies are available only on a trade in basis therefore the defective assemblies must be returned for credit For this reason assemblies required for spare parts stock must be ordered by the new assembly part number 6 5 ABBREVIATIONS 6 6 Table 6 2 1151 abbreviations used in the parts list schematics and throughout the manual In some cases two forms of the abbreviation are used one all in capital letters and one partial or no capitals This occurs because the abbreviations in the parts list are always all capitals However in the schematics and other part of the manual other abbreviation forms are used with both lower case and upper case letters 6 7 REPLACEABLE PARTS LIST 6 8 Table 6 3 jis the list of replaceable parts and is organized as follows a Electrical assemblies and their com ponents in alpha numerical order by reference designation b Chassis mounted parts in alpha num erical order by reference designation c Miscellaneous parts 6 9 The information given for each part consists of the following a The Hewlett Packard part number b The total quantity Qty in the instru ment The description of the part d A typical manufacturer of the part in a five digit code manufacturer s number for the part 6 10 The total quantity for each part is given only once at the first appearance of the part number in the list NOTE Total quantities
566. panel AUX RF OUTPUT jack is measured with a power meter as the Signal Generator is tuned from 512 MHz to 500 kHz See Table 4 1 Recommended Test Abridgements EQUIPMENT Power Meter 435A Power Sensor HP 8482A 4 50 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 30 AUXILIARY OUTPUT TEST Cont d PROCEDURE 1 Connect power meter s power sensor to generator s rear panel AUX RF OUTPUT jack after setting Signal Generator s controls as follows COUNTER MODE EXPAND vocem mca OE LOCK Se OTE Source FM iow ow xw ecu cw OFF RANGE 256 512 MHz FREQUENCY TUNE 512 MHz RF ON OFF 2 Use generators FREQUENCY TUNE and RANGE controls to tune from 512 to 0 5 MHz The power meter should read 5 dBm at all frequencies 5 dBm 4 31 OUTPUT LEAKAGE TEST SPECIFICATION Leakage With all unused outputs terminated properly Leakage limits are below those specified in MIL I 6181D Furthermore less than 3 uV is induced in 2 turn l inch diameter loop 1 inch away from any surface and measured into 509 receiver DESCRIPTION A loop antenna is held one inch from all surfaces of the Signal Generator and any leakage monitored with a spectrum analyzer The loop antenna is suspended in a molding so that when
567. power between dc and 1100 MHz into generator output Auxiliary Output Rear panel BNC output is gt 5 dBm into 50 source impedance is approximately 500 Leakage With all unused outputs terminated properly Leakage limits are below those specified in MIL I 6181D Furthermore less than 3 uV is induced in a 2 turn l inch diameter loop 1 inch away from any surface and measured into a 50 Q receiver This per mits receiver sensitivity measurements to at least 0 03 uV in a shielded system Level Accuracy Output Level 15 to 10 to dBm 10 50 Total Accuracy as Indicated 1 5 dB 2 0 dB Level Meter Note Level Accuracy error consists of allowances for meter accuracy detector linearity temperature flatness attenuator accuracy and twice the measure ment error All but the attenuator accuracy and the measurement error can be calibrated out with a power meter at a fixed frequency and a fixed vernier Setting MODULATION CHARACTERISTICS General Internal AM and FM External AM FM and PULSE Simultaneous AM and FM or PULSE and FM Types Internal Modulation Sources independently adjustable output is available at front panel Standard Frequency Fixed 400 Hz and 1 kHz 2 Output Level Indicated 10 mVrms to 1 Vrms into 600 Q Optional Internal Variable Audio Oscillator Option 001 Frequency Variable 20 Hz to 600 kHz 10 in 5 decade continuous bands plus fixed 400 Hz and 1 kHz
568. precautions pertinent to etched circuit repair work a Avoid unnecessary component substitu tion it can result in damage to the circuit board and or adjacent components b Do not use a high power soldering iron on etched circuit boards Excessive heat may lift a conductor or damage the board c Use a suction devicd Table 8 1 or wooden toothpick to remove solder from com ponent mounting holes DO NOT USE A SHARP METAL OBJECT SUCH AS AN AWL OR TWIST DRILL FOR THIS PURPOSE SHARP OBJECTS MAY DAMAGE THE PLATED THROUGH CON DUCTOR d After soldering remove excess flux from the soldered areas and apply a protective coating to prevent contamination and corrosion Avoid get ting flux remover on the printed circuit board extractors See Table 8 1 for recommendation 8 28 Etched Conductor Repair 8 29 A broken or burned section of conductor can be repaired by bridging the damaged section with a length of tinned copper wire Allow adequate overlay and remove any varnish from etched conductor before soldering wire into place 8 30 Component Replacement 8 31 Remove defective component from board NOTE Although not recommended on boards with high frequency signals or where both sides of a board are accessible axial lead components such as resistors and tubular capacitors can be replaced without un soldering Clip leads near body of defec tive component remove component and straighten leads left in board Wrap
569. r 10 of meter reading for greater than 1046 of full scale 512 1024 Incidental AM at 400 Hz and 1 kHz rates FM 3 dB Bandwidth 0 596 AM for FM up to 1 8 maximum allowable Internal and External ac 20 Hz to 250 kHz deviation External dc dc to 250 kHz lt 1 AM for FM at maximum allowable deviation With 8640B Option 004 in LOCKED MODE external FM is possible only for rates greater than 50 Hz Model 8640B Option 004 General Information Table 1 1 Specifications 6 of 6 COUNTER CHARACTERISTICS External RF Input Frequency Range 1 Hzto 550 MHz Sensitivity 100 mVrms ac only into 502 7 dBm Maximum Input 1 3 Vrms 15 dBm External Count Resolution 6 digit LED DISPLAY Mode Normal Expand x10 Expand x100 0 10 MHz 0 550MHz External Reference Input 5 MHz nominally 20 5 Vp p 5V maximum into 10000 Internal Reference Characteristics after 2 hr warmup Accuracy after calibration at 25 C Better than 1 ppm for 15 to 35 Better than 3 ppm for 0 to 55 C Drift Rate Time 0 05 ppm per hr lt 2 ppm per year Temperature 2 ppm total variation for room ambient 15 to 35 C Line Voltage 0 1 ppm Frequency Tuning gt 20 ppm using internal time base vernier Rear Output nominally 20 5 Vp p into 5000 This will drive another 8640B GENERAL CHARACTERISTICS Operating Temperature Range 0 to 55 C Power Requirements 100 120 220 and 240 vol
570. r amplifier U11 The outputs of the first three dividers drive complementary output OR gates U10A U13B and U15B which drive the next divider stage with one outpul and another complementary output OR gate UTOR U13A U15A with the other The latter gates drive output transformers T2 and in push pull and are enabled by inverter transistors Q2 Q3 and Q4 respectively When an output OR gate is enabled the next divider stage is disabled Note that ground is a logical high and negative or open a logica low for EECL and ECL devices The Q and outpuls of the next two stages each drive NOR gates UL7TB U17C U19B and U19C in push pull which in tum drive transformers T4 and 5 in push pull The final four divider stages operate in a manner similar to the previous two siages The NOR gate outputs however drive a common output transformer T6 The last NOR gate output pair is enabled through diodes CR2 and connected in a logical OR configuration All output transformers drive pi network pads which are switched onto the line leading to the modulator circuits The attenuation of the first three pads H6 8 R12 14 and R18 20 is set from 3 lo 6 dB to prevent excessive signal level from being applied Lo A26U2 Service Sheet 12 The attenuation level is set by changing the values of the resistors Schmitt Trigger A10A2 Amplifier 01 is a Schmitt Trigger which senses when the voltage proportion
571. r Assembly Disconnect A9A2 Interconnect Assembly from switch Loosen two setscrews on coupler at the RANGE switch shaft Do not disturb coupler at the A10 Divider Filter Assem bly shaft Remove PEAK DEVIATION RANGE and FM vernier knobs The knobs are secured to their shafts with allen setscrews Remove two nuts and lockwashers that secure the switch assembly to front panel Lift assembly from instrument Remove coupler from RANGE switch shaft only Disconnect 30 pin edge connector A9A2P1 from the mother board Model 8640B Option 004 08640 90073 CHANGE 7 Cont d A9 Assembly Removal Procedure cont d 11 Reinstall switch assembly besetting both switches four positions ccw from full cw the Divider Filter shaft should also be in this position and by reversing the procedures in steps one through ten NOTES The detents of both A9 and A 10 assembly switches must align and correspond to the same positioAs Check that the actual RF output frequency agrees with the counter indication on all bands Adjust the coupler for minimum binding and tighten the setscrews very securely CHANGE 8 Page 9 Table 1 1 Under SPECTRAL PURITY make the foILOWING changes to the Harmonics specification Delete gt 35 dB below fundamental of 0 5 to 128 MHz Change 128 to 512 MHz to 0 5 to 512 MHz Page 1 16 Table 1 1 Under MODULATION CHARACTERISTICS General make the following changes to the specification for Optional Intern
572. r U28 and flip flop U1B The Q output of U1B goes high and inhibits the input to the main counter by means of OR gate U14C and enables the Stall Counter by means of AND gate U17B When counter 1728 reaches count of four output Qg goes high and the output of NAND gate U2A goes low The borrow output of counter U24 is high because the count down CD input is held high by U14C The low from the output of SERVICE SHEET 20 Cont d U2A causes a low at the output of U13C and also U13D Since the output of U14C is high the output of NOR gate U25A is low The low from U13D causes a high at the output of NOR gate U25B and clocks the count down CD input of U23 once If U23 is ata zero count its borrow output clocks counter U22 If U22 is at zero it clocks counter U21 etc When Stall Counter U28 reaches the count of eight output Qr goes high and causes a high on the D input of flip flop U1B The next clock causes the Q output of UIB to go low which inhibits the clock to the Stall Counter and enables the clock to the main counter In the normal count down mode decade counters U19 to U24 form a synchronous counter OR gates U27A to U27C and AND gate U13C have high outputs unless all previous counters are at the zero count When any of the OR gates or AND gate U13C are low the output of the following NOR gate to 5 or U25B goes high on the next clock input Thus each counter changes count only at the occurence of a clock input and o
573. r division scan width to 5 kHz and input attenuation to 10 dB Set the display controls for a linear display with 0 1 mV div set display smoothing video filter to 100 Hz and set the tracking generator for 0 dBm output Set oscilloscope for dc input coupling vertical to 5 mV div and horizontal to 0 5 ms div Set digital voltmeter s noise filter to maximum filtering range to 10V and function to dc NOTE The noise filter between the analyzer and the DVM can be used instead of or with the DVM S noise filter whenever the DVM s reading is obscured by noise To use this filter switch it off if it is on for approximately two seconds to allow the capacitor to charge then switch it on wait approximately 30 seconds to allow the filter to reach the average value of the signal then take the reading Phase lock the system by tuning the reference signal generator s frequency to center the 3 MHz IF signal on the analyzer s display Set analyzer s span width per division to zero then tune reference signal generator to indicate phase lock on the oscilloscope the signal will peak then become O Vdc when phase lock is reached NOTE Care must be taken to ensure that all measurements are taken during phase lock Also the tracking generator s tracking adjustment should be periodically checked to ensure that the trace is peaked on the analyzer Adjust analyzer s display sensitivity controls for a 500 mVdc reading on the DVM Measure the
574. r high frequency sensitivity o High band low band switch a b c d e f g h i j k 1 Meter and Modulation Oscillator Checks a Panel meter accuracy b Modulation oscillator frequency accuracy kHz Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 12 BASIC FUNCTIONAL CHECKS Cont d Table 4 3 Record of Basic Functional Checks 2 of 2 Meter and Modulation Oscillator Checks Cent d c Modulation oscillator frequency accuracy Option 001 XI X10 X100 X3k Output Level Checks a Output level accuracy b Output level accuracy 0 5 to 512 MHz AM and Pulse Checks AM accuracy and distortion DEMOD OUTPUT accuracy Pulse level accuracy Output attenuator FM Check b FM accuracy px ae Lees c Output level flatness 5 108 to 336 MHz 4 12 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 13 FREQUENCY RANGE TEST SPECIFICATION Range 500 kHz to 512 MHz in 10 octave bands Bands and Band Overlap Bands extend 10 below and 7 above the nominal limits shown below Nominal Frequency 64 External Bands 8 16 16 32 32 64 128 Doubler Band 512 1024 MHz Frequency 14 4 28 8 57 5 230 to 550 Range MHz to to to without Ex with overlap 1 34 3 68 7 137 5 ternalDoubler DESCRIPTION The frequency range is verified by using a frequency counter to measure the frequency
575. r or OUTPUT LEVEL vernier With AM set to INT the internal modulation oscillator signal is present at the AM OUTPUT jack f 600 ohm source impedance Its level is set by AUDIO OUTPUT LEVEL e Figure 3 7 Setting the Modulation Controls 1 of 5 3 16 Model 8640B Option 004 Operation SETTING MODULATION To use an external modulation signal set AM to AC or DC if modulation signal is less than 20 Hz Apply the signal to the AM INPUT jack 2000 ohm load impedance The Signal Generator requires 1 Vpk 0 7071 Vrms for 100 modulation Set percent of modulation with the MODULATION vernier o percent AM is indicated by the meter The meter reading is accurate when is set to DC only if no dc offset is applied to the AM INPUT jack The meter responds to the positive peak of the ac component of the modulating signal A path for sensing the phase of the demodulated audio signal is provided at the DEMOD OUTPUT jack DEMOD OUTPUT provides 0 5 Vrms signal when an internal AC DC switch A26A8S1 Demodulation Amplifier Assembly is in the AC position With the AC DC switch in this position the Signal Generator is compatible with most vacuum tube audio oscillators used in VOR receiver testing When the AC DC switch is in the DC position a 0 1 Vrms signal with 1 414 0 010 Vdc offset is present which is compatible with solid state VOR audio oscillators For minimum phase shift of the audio signal between
576. r removal procedure Initial Control Settings Meter Function 22222222 VOLTS COUNTER MODE EXPAND Off LOCK Off Source 2 INT AM OFF EM OFF RANGE 2 256 512 MHz FREQUENCY TUNE 550 MHz OUTPUT LEVEL Switches 10 dBm 10 0 OUTPUT LEVEL CAL RF ON OFF ON RF Divider Circuits The quickest way to isolate a divider filter problem is to use the front panel controls to set various frequencies and frequency ranges while monitoring the output voltage meter Usually a problem will appear as shown in the following table RF Filters A10A1 SERVICE SHEET 10 oervice SERVICE SHEET 11 Cont d Symptom No output on one band only No output on one band and all bands below that band Model 560205 Ciption OU Probable Cause Detective output circuit for one of the dividers a filter or a slide switch Defective divider or 16 32 MHz low band filter or 0 5 to 8 MHz divider output transformer Low power at highest end of bands 8 to 1024 MHz only Defective geometric mean switching high band Overly high harmonics at lowest end of bands 8 to 1024 MHz only filters not being switched in Defective geometric mean switching low band filters not being switched in Intermittent
577. r s RF output is detected and fed to the analyzer s input Amplitude variation is measured on the analyzer s display See Recommended Test Abridgements AUDIO SPECTRUM ANALYZER CRYSTAL DETECTOR Figure 4 18 AM 3 dB Bandwidth Test Setup 4 56 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 34 3 BANDWIDTH TEST Cont d EQUIPMENT Audio Spectrum Analyzer HP 141T 8552B 8556A Crystal Detector e amp x xx HP8471A 1KQ Resistor HP 0757 0280 PROCEDURE l Connect equipment as shown if Figure 4 18 after setting Signal Generator s controls as follows Meter Function 0 AM COUNTER MODE E OFF LOCK 2 amp s 4 ow 9 amp Source 22065 x o9 amp e INT AM wo We due dt RUE e xc MODULATION FM x OFF RANGE 816 FREQUENCY TUNE OUTPUT LEVEL Switches 43 dBm OUTPUT LEVEL Vernier CAL RF ON OFF JON 2 Set analyzer s center frequency controls to 1 kHz fixed not scanning and adjust tracking generator s output level controls for 50 AM as indicated on Signal Generator s panel meter 3 Now set spectrum analyzer s resolution bandwidth to 1 kHz and set frequency span scan width controls for a zero to 100 kHz span Set display for 2
578. r service by removing the Riser Assembly from 10 2 and installing A10A2 in the riser socket AIOAI XAIOA3A and B Remove the riser evenly to avoid cracking the connector 2 When replacing transistors on A10A2 assure that the cans will not contact the casting top cover AI0A1 Access 9 Remove four pan head screws with lock washers that secure casting center section to casting Remove three power supply circuit boards A18 A20 and A22 that are betwee AIO Assembly and rear panel 7 Remove casting center section 8 78 10 1 Assembly be checked adjusted by installing the 10 2 Assem Model 8640B Option 004 bly in the riser socket AIOAIXAIOA3A and B and reinstalling the power supply circuit boards A18 A20 and A22 10 1 Removal 8 Turn instrument upside down and remove bottom cover see Service Sheet G CAUTION While working with and around the semi rigid coaxial cables in the generator do not bend the cables more than necessary Do not torque the RF connectors to more than 2 inch pounds 9 Remove FM circuit boards A5 and A7 and the A3A4 Connector Board Assembly see Service Sheet F 10 Disconnect four semi rigid coaxial cables from bottom of A10 Assembly cable W3 and A10A1J3 cable W7 at A1OA1J2 cable 5 at A10A1J1 and cable W8 at A10A1J4 A10A1J2 and J3 are located in area occupied by FM circuit boards A10A1JI and are lo
579. raticule on the display 100 dB down 40 dB 4 24 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 21 SINGLE SIDEBAND PHASE NOISE TEST SPECIFICATION SSB Phase Noise at 20 kHz Offset from carrier Averaged rms noise level below carrier stated in a 1 Hz bandwidth 256 MHz to 512 MHz gt 130 dB from 230 to 450 MHz increasing linearly to gt 122 dB down at 550 MHZ 0 5 MHz to 256 MHz Decreases approximately 6 dB for each divided frequency range until it reaches SSB Broadband Noise Floor of gt 130 dB DESCRIPTION Phase noise is measured with a spectrum analyzer A reference signal generator and a mixer are used to down convert the test Signal Generator s CW signal to O Hz the two signal generators are phase locked together Then the spectrum analyzer measures SSB phase noise at a 20 kHz offset from the carrier NOTE This test measures the total SSB phase noise of both generators Therefore the reference signal generator must have SSB phase noise that is less than or equal to the specification for the test generator REFERENCE SIGNAL GENERATOR 10 dB STEP ATTENUATOR OSCILLOSCOPE NOISE PHASE LOCK CIRCUIT WITH POWER SUPPLY VERTICAL INPUT Figure 4 6 Single Sideband Phase Noise Test Setup 4 25 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 21 SINGLE SIDEBAND PHASE NOISE TEST Cont d EQUIPMENT Reference Signal Generator
580. reference tests DESCRIPTION A frequency counter digital to analog converter and strip chart recorder are used to measure the frequency drift after warm up and restabilization time See Table 4 11 Recommended Test Abridgements NOTE For these tests ambient room temperature and line voltage must not change D A CONVERTER AND RECORDER MODEL 86408 OPTION O4 SE FREQUENCY COUNTER AUX RF OUTPUT REAR PANEL Figure 4 1 Frequency Stability us Time and Restabilization Time Test Setup EQUIPMENT Frequency Counter HP 5327C Option 003 Digital to Analog Converter HP 581A Option 002 Recorder for D A Converter HP 680 PROCEDURE 1 Connect equipment as shown ih Figure 4 1 after setting Signal Generator s controls as follows This specification applies only if the RF ON OFF switch has been wired to turn the RF Oscillator off 4 16 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 15 FREQUENCY STABILITY VS TIME AND RESTABILIZATION TIME TEST Cont d COUNTER MODE EXPAND Off LOCK x ux 7051 ow VOTE Sourte INT FM OFF 221010101010 32 64 MHz FREQUENCY 50 MHz RF ON OFF ON 2 Set frequency counter to read frequency directly i e not divided down Use a 1s gate time so that the last three digits span from 000 to 999
581. ring cua I Logic Levels 2 L 8 6 L 4 5 8 3 Assembly Information idek Bs 8 14 8 4 Schematic Diagram Notes 4 94 85 Meter Drive Amplifier Data 857 L53 Total Count of Time Base Reference BY Counters U13 014 and 015 Count Modes of Counters A8A3U13 6 2 and Ul4 8 8 Count Modes of Counter ASA3UIS Data Inputs of Decimal Point 6 5 Shift Register 8 56 16 45 APPENDIXES AJ Additional Authorization List 1 iv Table of contents Model 8640B Option 004 ILLUSTRATIONS Figure Page Figure Page 1 1 HP Model 8640B Option 004 Signal Generator Internal Modulation Oscillator Distortion Option 001 and Accessories Supplied 1 0 Test Setup Measured Single Sideband Noise vs Offset a 3 dB Bandwidth Test Setup from Carrier 4 12 4 19 JAM Distortion Test Setup 4 58 1 3 Specified Signal to Phase Noise Ratio iso 4 20 Sensitivity and Accuracy Test Setup 1 4 AM Distortion vs AM Rate DA 4 21 Peak Incidental Phase Modulation sere RF Teo oss t Test Setup 4 63 6 istortion vs ate 4 22 Demodulated Output Accuracy Test 520 1040 MHz Notch Filter Lad i ide Setup E FM Linearity Circuit 1 20 EZ JM Ph Shif T S 1 9 Noise Phase Lock Circuit 121 issajous Display 4 70 Line Selector 4 25 Flatness Test Setup l 4
582. rnier in CAL position 108 to 118 MHz and 329 to 336 MHz carrier and between 20 and 80 AM An internal selector switch selects only or ac and at the de modulated output AC Only Output AC DC Switch to AC Directly proportional to AM depth 90 to 150 Hz modula tion rate AM equals 20 0 6 per Vrms 0 to 55 C 20 0 4 per Vrms 20 to 30 C 20 0 2 per Vrms 20 to 30 C Using the DEMOD CAL label provided by the factory AC and DC Output AC DC Switch to DC AC out put voltage is directly proportional to AM depth 90 to 150 Hz modulation rate 95 AM equals 100 3 per Vrms 0 to 55 C 100 2 per Vrms 20 to 30 C 100 1 per Vrms 20 to 30 C Using the DEMOD CAL label provided by the factory DC output equals 1 414 0 010 Vdc with vernier in CAL position External input Impedance nominally 2KQ Frequency Response 0 05 dB from 90 Hz to 150 Hz 108 to 118 MHz and 329 to 335 MHz 0 05 dB from 9 kHz to 11 kHz 108 to 118 MHz Phase Shift from Audio Input to Demodulated Output 108 to 118 MHz AM source selector to DC 30 Hz lt 0 01 30 Hz to 10 kHz lt 3 9 kHz to 11 kHz lt 1 difference from 9 to 11 kHz 1 performance Tests and Adjustments pertaining to these specifications should be performed at least every three months to ensure instrument accuracy 2 When AM 80 and when measured across a load impedance 21 factory calibration
583. rom carrier sed Figures 1 and 1 3 about 1 Hz and for 20 Hz to 15 kHz is about 4 Hz These are measured values in the 230 to 550 MHz 2130 dB down range and calculated for divided ranges knowing the noise distribution OUTPUT CHARACTERISTICS Range 15 dBm to 142 dBm 1 3V to 0 018 uV Level Flatness Attenuators a 10 dB step attenuator and a 1 dB lt 0 75 dB from 0 5 to 512 MHz referred to output step attenuator with vernier allow selection of at 190 MHz any output level over the full output level range lt 0 5 dB from 108 to 336 MHz referred to output Vernier 22 dB continuously variable from a CAL at 190 MHz detent position Flatness applies to 10 to 10 dBm These specifications are given for the 8640B Option 004 internal reference when using an external reference drift in the locked mode will depend on the external reference characteristics This specification apply only if the RF ON OFF switch has been wired to turn the RF Oscillator off 1 9 General Information Model 8640B Option 004 Table 1 1 Specifications 3 of 6 OUTPUT CHARACTERISTICS Cont d Impedance 50 Q ac coupled VSWR 2 0 on 3V and IV output ranges 1 3 on all other ranges Reverse Power Damage Level 40 Vdc maximum 20 dBm maximum on 3V and IV output ranges 27 dBm maximum on all other ranges Reverse Power Protection Option 003 Protects signal generator from accidental applications of up to 25 watts 44 dBm of RF
584. rrier diodes The new diodes will prevent the possibility of the RF detector filter capacitors A26A1C5 C6 or C7 being switched in when not selected This can occur if the reverse leakage current through the diodes which flows from the 20V to the 5 2V supply is sufficient to turn on transistors A26A2Q8 or Q9 Refer to Service Sheet 13 7 22 To make the modification order HP Part Number 1901 0539 On A26A2 AM Offset and Pulse Switching Assembly replace 25 2 9 and CR13 7 23 Al 1 Variable Frequency Modulation Oscil lator Option 001 Improvement Serial Number Prefixes 1350A and Below 7 24 Possibility of failure of the Variable Fre quency Modulation Oscillator Option 001 can be reduced by adding insulator 11 17 between spur gear Al IAIMP3 and the variable capacitor AllC1 The insulator prevents the shaft or metal insert in the gear from shorting the capacitor to Model 8640B Option 004 ground This modification is recommended at time of oscillator service or repair 7 25 Install insulator as follows Order HP part number 08640 00087 insulator b Remove 11 Variable Frequency Modul ation Oscillator see Service Sheet D c Remove two 4 40 pm head screws and two hex nuts which secure the Audio Oscillator cover Remove cover d Remove adhesive backing from insulator and apply to the tuning capacitor behind the plastic gear 11 1 and small spur gear 2 NOTE If t
585. rt it may be desirable though not necessary to replace the front window the skirt will slightly cover some of the markings near it The correct part number for the window is in the parts list CHANGE E Page 6 33 Table 6 3 Change A26A2CRO to 1910 0016 DIODE SWITCHING 1 us 60 60 MA Change A26A2CR13 to 1910 0022 DIODE SWITCHING GE 5V MAX VRM 60 MA NOTE paragraph 7 20j for recommended instrument modification CHANGE F Page 6 14 Table 6 3 Delete A8A2C31 Table 6 3 Delete A11MP17 NOTE See paragraph 7 20 recommended instrument modification Service Sheet 21 schematic Delete A8A2C31 NOTE See paragraph 7 26 for recommended instrument modification 7 8 Model 8640B Option 004 Manual Changes MANUAL CHANGES CHANGE G Page 5 34 pdragraph 8 40 Add the following after step 6 Connect DVM to 4 2 and adjust OFFSET adjustment A3A4R5 for 0 5 mVdc at A3A4TP2 and 6 8 Table 6 3 Replace entire A3A4 sub assembly list with the following A3A4 08640 60040 CONNECTOR BOAR D ASSY A3AACI 0160 2055 CAPACITOR FXD 0 01 UF 480 2096 100 WVDC A3A4C2 0160 2055 CAPACITOR FXD 0 01 UF 80 20 100 WVDC A3AARI 2100 3161 RESISTOR VAR TRMR 20K OHM 10 C A3A4R2 2100 3109 RESISTOR VAR TRMR 2K OHM 10 C A3A4R3 2100 3109 RESISTOR VAR TRMR 2K OHM 10 C A3A4R4 2100 3154 RESISTOR VAR TRMR IK OHM 10 C A3A4R5 2100 3154 RESISTOR VAR TRMR IK OHM 10 C A3A4R6 0757 0442 RESIST
586. rum Analyzer HP 141T 8554B 8552B Digital Voltmeter HP 3480D 3484A Power Supply 6215 PROCEDURE VERTICAL OUTPUT 1 Connect the equipment as shown ih Figure 5 1 after setting the Signal Generator controls as follows Meter Function TRUM COUNTER MODE EXPAND LOCK Source AM MODULATION FM RANGE FREQUENCY TUNE OUTPUT LEVEL Switches OUTPUT LEVEL Vernier RF ON OFF 2 Connect the DVM to AM OUT A26A2TP3 and measure the dc voltage LEVEL off off INT AC Fully ccw OFF 128 256 MHz 190 2 MHz 10 dBm CAL ON de voltage at A26A2TP3 Adjustments Model 8640B Option 004 ADJUSTMENTS 5 29 RF DETECTOR OFFSET ADJUSTMENT Cont d 3 Set the power supply voltage to 1 Vdc 4 Set AM to DC and adjust MODULATION control to set the level at A26A2TP3 to one tenth the value in step 2 1 mVdc NOTE Verify the setting by switching AM between AC and DC and observing the variation 5 Set AM to AC Set the spectrum analyzer to observe the RF output with input attenuation 20 dB resolution bandwidth 300 kHz and linear display Set the frequency span to zero Hz and peak the trace on the display 6 Set the DVM filtering to maximum and connect it to the vertical output of the spectrum analyzer Adjust the vertical sensitivity to give a reading of 500 mVdc 7 Set AM to DC Increase the spectrum analyzer s vertical sensitivity by a factor of 10
587. s 4 Connect power meter sensor to oscillator output connector A3A1J1 Divider Filter Buffer Amplifier or A3A1J2 Counter Buffer Amplifier 5 Turn LINE to ON Tune FREQUENCY TUNE across entire band and note point of minimum power as read on power meter Tune to frequency of minimum power 6 Loosen two screws on the buffer amplifier board and slide board forward or backward until power reads 40 5 dBm Divider Filter Buffer Amplifier or 12 dBm Counter Buffer Amplifier Pushing board forward will increase power 7 Tighten screws and check power level across band Power should remain within the limits of 0 5 to 4 5 dBm Divider Filter Buffer Amplifier or 12 to 2 dBm Counter Buffer Amplifier 5 28 Model 8640B Option 004 Adjustments ADJUSTMENTS 5 38 RF OSCILLATOR OUTPUT POWER ADJUSTMENT Cont d 8 Disconnect power sensor and connect spectrum analyzer to the buffer amplifier output 9 Set analyzer s input attenuation to 50 dB resolution bandwidth to 300 kHz frequency controls to span 200 to 1200 MHz and vertical sensitivity reference level controls to 10 dBm 10 Tune oscillator across band and observe second and third harmonics which should be more than 17 dB below fundamental for all frequencies 11 W install RF Oscillator 12 Perform Harmonics Test 4 19 Output Level Flatness Test 4 27 Single Sideband Phase Noise Test 4 21 or Residual FM Test 4 24 and Output Leakage Test 4 31 5 3
588. s will be shown for each category The number of task hours specified by the work time figure represents the average time required to restore an item assembly sub assembly component module end item or system to a serviceable condition under typical field operating condi tions This time includes preparation time troubleshoot ing time and quality assurance quality control time in ad dition to the time required to perform the specitic tasks identified for the maintenance functions authorized in the maintenance allocation chart Subcolumns of column 4 are as follows C Operator Crew O Organizational D 1 TM 11 6625 2780 14 amp P F Direct Support H General Support D Depot e Column 5 Tools and Equipment Column 5 specifies by code those common tool sets not individual tools and special tools test and support equipment required to perform the designated function f Column 6 Remarks Column 6 contains an alphabetic code which leads to the remark ir section IV Remarks which is pertinent to the item opposite the par ticular code D 4 Tool and Test Equipment Require ments Sec III a Tool or Test Equipment Reference Code The num bers in this column coincide with the numbers used in the tools and equipment column of the MAC The numbers indicate the applicable tool or teat equipment for the main tenance functions b Maintenance Category The codes in this column in dicate the maintenance category a
589. s an error Resistor capacitor network R31 and C6 filters the voltage to the base of Q2 TROUBLESHOOTING It is assumed that a problem has been isolated to the counter phase lock circuits as a result of using the troubleshooting block diagrams Troubleshoot by using the test equipment listed below performing the initial test conditions and control settings and following the procedures outlined in the table NOTE If the counter phase lock circuits fail the usual effect is that the generator won t enter phase lock or that it won t break phase lock Ensure that the counter circuits shown on Service Sheet 20 operate correctly before checking the phase lock circuits SERVICE SHEET 21 Cont d When the procedures in the table require that a point be grounded they often depend upon multiple groundings ground probe or contact bounce to work correctly Clipping or touching a grounding probe to a point will usually supply enough multiple groundings to make the procedure work The procedures in the table also depend upon the sequence of switch settings and groundings If a procedure does not work correctly try ungrounding the test points resetting the switches to the Initial Control Settings and repeating the procedures Test Equipment Digital Voltmeter HP 34800 3484 Initial Test Conditions Top cover removed see Service Sheet G for removal procedure Counter Lock Assembly casting cover removed and A8A2 Counter Lock B
590. s instrument is to be energized via an autotransformer for voltage reduc tion make sure that the common ter minal is connectad to the earthed pole of the power source b The power cable plug shall only be inserted into a socket outlet provided with a protective earth contact The protective action must not be negated by the use of an extension cord without a protective conductor grounding c Before switching on the instrument the protective earth terminal of the instrument must be connected to a protective conductor of the power cord This is accomplished by ensuring that the instrument s internal earth terminal is correctly connected to the instru ment s chassis and that the power cord is wired correctly see Service Sheet 22 2 13 Mating Connectors 2 14 Mating connectors used with the Model 8640B Option 004 should be either 50 ohm type BNC male or Type N male connectors that are compatible with US MIL C 39012 2 15 Operating Environment 2 16 The operating environment should be within the following limitations Temperature 0 C to 55 C Humidity lt 95 relative Altitude lt 15 000 feet 2 17 A forced air cooling system is used to maintain the operating temperature required with in the instrument The air intake and filter are located on the rear panel and warm air is exhausted through perforations in the right hand side panel When operating the instrument choose a location that provides
591. scharges only during each pulse on period until the error is zero At low repetition rates and short on periods the capacitor discharge time is very long To correct for this Pulse Overload Detector senses the condition of large error 1 when the collector voltage of exceeds 0 4 Vdc and switches a discharge resistor on to bring the system to a near zero error condition Meter Amplifier Amplifier Ul A is an inverting amplifier with a gain of about 1 2 adjusted by R12 which scales the detector output voltage to drive the metering circuits Capacitor C8 filters any superimposed modulation signal on the detector output Modulator Overload Detector If the OUTPUT LEVEL vernier setting or input modulation signal requires the output to exceed its maximum capability Modulator Overload Detector U2 senses the condition and lights the REDUCE PEAK POWER annunciator A6DS3 Service Sheet 16 The reference voltage is set by resistors R29 R30 and R31 When the output from the OUTPUT LEVEL vernier exceeds the SERVICE SHEET 12 Contd reference the output of U2 goes high and Q8 turns on which turns on Q9 and the annunciator Since the overload condition may be of short duration capacitor C13 holds the output of U2 high to keep the annunciator lit for a longer period TROUBLESHOOTING It is assumed that a problem has been isolated to the AGC amplifier or the modulator as a result of using the troubleshooting block diagrams Tr
592. scillator Service Sheet 2 The RF source is a 256 to 512 MHz cavity tuned oscillator that is mechanically tuned by the FRE QUENCY TUNE and FINE TUNE controls The oscillator can also be electrically tuned over a smaller range by the FM and the counter lock circuits The FM circuits amplify and shape the modulation input to provide linear calibrated frequency modulation The phase lock circuits tune the oscillator to phase lock it to a reference FM inputs can be either external ac or dc coupled internal from the modulation oscillator or an accurate 1 Vdc useful for FM calibration AM AGC Circuit and Output Amplifier Service Sheet 3 The RF oscillator drives the RF dividers a chain of binary dividers which divide the RF for the lower nine frequency ranges The RF filters remove the harmonics from the RF signal The AM AGC circuits form a feedback system to control the amplitude of the output and to provide AM or pulse modulation The detector senses the level of the RF signal from the RF output amplifier A summing amplifier compares the detector output against an input reference and drives the modulator The modulator acts as a 8 18 Model 8640B Option 004 current controlled attenuator to control the RF level The reference to the summing amplifier consists of the level reference which comes from the output level vernier and the modulation signal if present The modulation signal can be either external ac or dc
593. sembly Improvement Serial Number Prefixes 1333A and Below A18 A20 and A22 Power Supply Regula tor Improvements Serial Number Prefixes 1333A and Below 7 16 7 15 Variable Frequency Modulation Oscillator Improvements Serial Number Prefixes 1339A and Below 7 16 7 18 A12 Rectifier Assembly Input Crowbar Failures Serial Number Prefixes 1339A and Below 7 16 Reliability Bd Pulse Circuits Serial Number Prefixes 1345A and Below 1 16 7 23 Variable Modulation Oscillator Option 001 Improvement Serial Number prefixes 1350A and Below Improvement in lock bility Serial Number Prefixes 1350A and Below odas 44 6V Regulator Improvement Serial Number Prefixes 1405A and Below Line Switch Modification Serial Number Prefixes 1406A and Below Reduction in Popcorn Noise on Power Supplies Serial Number Prefixes 1406A and Below T 7 18 7 35 Recommended Fuse Revindement for 220 240V Operation Serial Number Prefixes 1423A and Below 7 18 VIT SERVICE D amp T 8 1 Introduction Low d 8 5 Principles of Operation do LE Troubleshooting M 2 5 8 12 Recommended Test 1 E 14 Service Aids Im A 83 Factory Selected Components L amp 3 Btched Circuits 8 3 28 Etched Conductor Renae A 8 3 Component Replacement
594. sheet with the schematic Al Assembly Illustrated Parts Breakdown is located on Service Sheet A Assembly Illustrated Parts Breakdown is located on Service Sheet B A8 Assembly Illustrated Parts Breakdown is located on Service Sheet C and All Assemblies Illustrated Parts Breakdowns are located on Service Sheet D AlO Assembly Illustrated Parts Breakdown is located on Service Sheet E A19 Assembly Illustrated Parts Breakdown is located on Service Sheet A A26 Assembly accessible from both top and bottom of instrument Illustrated Parts Breakdown is located on Service Sheet Model 8640B Option 004 Lo oJ Service Table 8 4 Schematic Diagram Notes 1 of 3 Resistance in ohms capacitance in picofarads inductance in micro henries unless otherwise noted Asterisk denotes a factory selected value Value shown is typical Part might be omitted See Table 5 1 See Backdating Tables 7 and 7 2 Tool aided adjustment 0 Manual control Encloses front panel designation Encloses rear panel designation Circuit assembly borderline Other assembly borderline Also used to indicate mechancial inter connection ganging and RF shielding Heavy line with arrows indicates path and direction of main signal Heavy dashed line with arrows indicates path and direction of main feedback Wiper moves toward CW with clockwise rotation of control as viewed from shaft or knob Nu
595. sistance Measure voltage applied to each winding of motor Measure period of voltages applied to windings of mot or 5 2 01 Correct operation and re sistance As shown on schematic approximately sinu soidal As shown on schematic Model 8640B Option 004 Check supply load circuits for short Check 1801 and supply load circuits Replace faulty component Check appropriate compon ents Check speed regulator circuits Model 8640B Option 004 Figure 8 75 A18 5 2V Regulator and Fan Driver Assembly Component Locations Al POWER SUPPLY MOTHER 17 ASSEMBLY 08640 60001 MOTHER BD en T TANT SERIES 1 PIO p REGULATOR EER 18 XO5 Q5 1854 0063 pom CROWBAR amm NOTE D 6 0177 R8 R9 38 3K 1 0 REFERENCE DESIGNATIONS WITHIN OUTLINED ASSEMBLIES ARE ABBREVIATED FULL DESIGNATION IN CLUDES ASSEMBLY NUMBER e g R OF ASSEMBLY Al IS AIR DESIGNATIONS OF OTHER COMPONENTS ARE COMPLETE AS SHOWN 5 2 FAN DRIVER m Q1 R18 i 1853 0020 147 45V y i 1854 0003 T sis 10K 8 9 5 2V 5 2V 5 2V 52V REGULATOR AND FAN CIRCUITS 86408 OPTION 004 1418A t gt WS ie AJ Q9 T is 3 853 0027 2 1 No A16 FAN MOTOR ASSEMBLY 08640 60119 1853 AJ 0050 0050 14 20 P1 1254 CR i i 1 Vpop 14 Vp p 4 1 20 ms 14
596. specifications and their acceptable limits Test results recorded at incoming inspection can be used for comparison in periodic maintenance and trou bleshooting and after repairs or adjustments 4 8 TEST PROCEDURES 4 9 It is assumed that the person performing the following tests understands how to operate the specified test equipment Equipment settings other than those for the Model 8640B Option 004 are stated in general terms For example a test might require that a spectrum analyzer s resolution bandwidth be set to 100 Hz however the time per division setting would not be specified and the operator would set that control so that the analyzer operates correctly 4 10 It is also assumed that the person performing the tests will supply whatever cables connectors and are necessary The Test Accessories table in Section I lists the requirements for some of these items 4 11 Unless otherwise specified set the following controls as shown TIME BASE INT EXT on rear pene INT TIME BASE VERNIER CAL Use FINE TUNE in with FRE QUENCY TUNE to set whatever frequency is required Use the COUNTER MODE EXPAND controls whenever necessary to obtain required counter resolution CAUTION To avoid the possibility of damage to test equipment read completely through each test before starting it Make any preliminary control settings necessary for correct test equipment operation NOTE T ble 4 1 contains a
597. st oscillator Change the corresponding capacitor if necessary for best flatness less than 3 dB down at 250 kHz rate Increase capacitance to decrease deviation 250 kHz rate FREQUENCY PEAK DEVIATION RANGE MHz Range Capacitor 512 1024 A9A1A2C8 256 512 A9A1A2C7 128 256 A9A1A2C6 NOTE Changing any capacitor will likely affect flatness on other ranges Page 5 3 Table 5 Delete A9C8 see Change 1 Add the following Range of Values Basis of Selection A9A1A2C6 0 56pF A9A1A2C7 500 900 pF See paragraph 5 21 A9A1A2CS 6 750 2000 pF and 6 18 Table 6 3 Raplace the entire A9 assembly parts list with the following list A9 DEVIATION AND RANGE SWITCH ASSEMBLY 9 1 08640 60179 SWITCH ASSEMBLY A9AIMP1 0380 0013 SPACER 1 0 LONG A9A1MP2 03800013 SPACER 1 0 LONG A9A1MP3 0510 0005 RING RETAINER 1 4 DIA A9A1MP4 05100005 RING RETAINER 1 4 DIA 9 5 0510 0005 RING RETAINER 1 4 DIA A9AMP6 0510 0015 RING RETAINER EXT A9AIMP7 05100052 RING EXT 0 125 DIA 9 8 05100052 RING EXT 0 125 DIA 1 8 1430 0759 GEAR SPUR 9 10 1430 0772 GEAR PLANET 11 1430 0772 GEAR PLANET A9A1MP12 1430 0773 GEAR COMBINATION A9A1WP13 1430 0774 GEAR COMBINATION A9AIMP14 14600019 SPRING COMPRESSION 7 37 Model 8640B Option 004 CHANGE 7 Cont d A9AIMP15 9 1 16 9 1 17 9 1 18 9 1 19 9 1 20 9 1 21 9 1
598. step 7 by 0 3536 0 3536 x Vdc from step 7 Vdc Set the DVM to read ac volts and adjust AM ADJ A26A2R19 to give a reading equal to the value calculated in step 8 1 mVrms Set the DVM to read dc volts and connect it to DEMOD OUTPUT Adjust DC GAIN 26 8 10 to give a reading of 1414 1 mVdc Set the AC DC switch A26A8S1 to AC Adjust AC OFFSET A26A8R6 to give a DVM reading of 0X1 mvdc Set the DVM to read ac volts Adjust AC GAIN A26A8R8 to give a reading of 2500 1 mVrms Perform AM Accuracy Adjustment 5 32 Model 8640B Option 004 Adjustments ADJUSTMENTS 5 32 AM ACCURACY ADJUSTMENT REFERENCE Service Sheet 15 DESCRIPTION The Signal Generator is amplitude modulated and the modulation is demodulated by a peak detector in a spectrum analyzer set to a zero frequency span The ac and dc components are measured with a voltmeter at the detector output vertical output of the spectrum analyzer First the dc component is set to 282 8 mVdc plus a detector offset correction The the ac component is measured and the percent AM calculated as 1 2 the ac component read in mVrms The demodulator amplifiers are then adjusted to give the correct voltage at the demodulator output Because of the required measurement accuracy the accuracy of the spectrum analyzer s detector offset must be known to 1 mV The offset voltage is calculated by measuring the change in the detector output for a chage in RF input and assuming a linear
599. stments T Troubleshooting 1 15 General Information Model 8640B Option 004 Table 1 2 Recommended Test Equipment 8 of 6 Instrument Type Critical Specifications Suggested Model Use HP 5327C P A Standard Reference Accuracy 3 x 107 month aging rate lt 5 x 10 rms short term stability lt 2 5 x 1075 0 50 C temperature stability Frequency Counter cont d Optional Reference Accuracy lt 3 x 10 aging rate 1 x 10710 s rms short term stability lt 1 x 10 0 50 C temperature stability Option H49 Optional Digital Output 1248 with 1 on state positive compatible with D A Converter Option 003 Range 0 1 Hz to 1 kHz Output Impedance 6002 Function Generator HP 3300A P Output Level gt 1 V pk FM Linearity Circuit See Figure 1 8 HP 08640 60503 Mixer 3 required e SMS HP 10514A A A Noise Phase Lock Figure1 9 HP 08640 60504 Circuit Oscilloscope 50 MHz Real Time 180A 1801A P A Sensitivity 5 mV division Internal External Sweep and Triggering P A T 1820C Range 0 45 550 MHz Input Level 20 to 20 dBm Accuracy 1 of reading Power Meter HP 435A With Power Sensor Thermocouple VSWR lt 1 2 1 With HP 8482A Power Supply Range 0 to 5V HP 6215A A Noise and Ripple 200 uVrms Positive ground return Pulse Generator Range 50
600. stortion should be less than 396 with trace peaked on analyzer display 90 AM 3 SPECIFICATION External AM Sensitivity 400 Hz and 1 kHz rates 0 1 0 005 AM per mV peak into 6009 with AM vernier at full cw position Indicated AM Accuracy 400 Hz and 1 kHz rates using internal meter 8 of reading on0 10 scale 9 of reading on 0 3 scale for greater than 10 of full scale DESCRIPTION AM sensitivity accuracy and meter accuracy are measured by comparing the actual amount of amplitude modulation to the level of the input modulating signal A spectrum analyzer is used to demodulate the AM The analyzer is used with zero frequency span at the carrier frequency A DVM is used to measure the ac and dc voltages at the analyzer s vertical output and the dc value of the carrier is set to 282 8 mVdc the rms value of the modulation is then a very accurate measure of percent AM percent AM is 1 2 the ac voltage in mVrms See Table 4 1 Recommended Test Abridgements 4 59 Performance Tests PERFORMANCE TESTS 4 36 AM SENSITIVITY AND ACCURACY TEST Cont d SPECTRUM ANALYZER VERTICAL Re OUTPUT TEST OSCILLATOR sil CALIBRATED STEP ATTENUATOR Model 8640B Option 004 Figure 4 20 AM Sensitivity and Accuracy Test Setup EQUIPMENT Spectrum Analyzer 20 HP 141T 8552B 8554B Digital Voltmeter HP 3480D 3484A Option 043 Test Oscillator RO oe 42 AP 652A Calibr
601. t The fan should be operating Set PEAK DEVIATION as indicated below The correct SCALE annunciator should light as 0 5 shown 0 10 0 3 Set PEAK DEVIATION to 10 kHz and FM to INT The REDUCE PEAK DEVIATION annunciator should light Set PEAK DEVIATION to 5 kHz and PEAK DEVIATION Vernier fully cw The REDUCE FM VERNIER annunciator should light Return FM to OFF Set OUTPUT LEVEL 10 dB switch fully cw AM to INT and MODULATION fully cw The REDUCE PEAK POWER annunciator should light Return OUTPUT LEVEL 10 dB switch to 10 dBm AM to OFF and MODULATION to fully ccw position 3 Counter and Frequency Checks Refer to step 1 for initial control settings a 4 6 Adjust TIME BASE VERN out of CAL position The UNCAL annunciator should light Return TIME BASE VERN to CAL Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 12 BASIC FUNCTIONAL CHECKS Cent d b Measure the frequency of the rear panel TIME BASE output with an accurate counter The frequency should be between 4 999 995 and 5 000 005 Hz with a 2 hour warm up and temperature between 15 and 35 C Set RANGE and counter EXPAND as indicated below The location of the decimal point should be correct as shown Decimal Point 128 1024 XXXXXX 16 128 XXXXXX 1 16 XXXXXX 0 5 1 XXXXXX 0 5 1 XXXXXX 0 5 1 XXXXXX At the last settings in step c the OVERFLOW annunciator should be on Using RANGE and FREQUENCY TUNE controls c
602. t Level 10 dB Meter Reading 11 steps ccw 91 di3m 12 steps ccw 101 di3m 13 steps ccw 111 dBm 14 Steps ccw 121 dBm 131 di3m Output Level Accuracy Test Complete Output Level 10 dB Meter Reading 15 dBm 16 5 dBm 14 dBm 15 5 dBm 13 dBm 14 5 dBm 12 dBm 13 5 dBm 11 dBm 12 5 dBm 10 dBm i 11 5 dBm Fully cw Fully cw Fully cw Fully cw Fully cw Folly cw 10 dBm 11 5 dBm dBm 10 5 dBm dBm 9 5 dBm dBm 8 5 dBm dBm 7 5 dBm dBm 6 5 dBm dBm 5 dBm dBm dBm 1 step cew dBm 1 step cew dBm 1 step ccw 1 5 dBm 1 step ccw 5 dBm 1 step 5 dBm 2 steps ccw 5 dBm 3 steps ccw 5 dBm 1 step ccw step 1 step 1 step ccw 1 step ccw 1 step ccw 1 step ccw 1 step ccw CU OS mVdc mVdc mV dc mVdc mVdc mVdc 445 6 mVdc 0 mVdc 445 6 mVdc 0 mVdc Performance Tests Model 8640B Option 004 Table 4 4 Performance Test Record 5 of 9 Test Description Output Level Accuracy Test Complete Cent d Output Level 10 dB Meter Reading 101 dBm 111 dBm 121 dBm 131 dBm 141 dBm Output Level Flatness Test Maximum reading Minimum reading Maximum reading Minimum reading Output Impedance Test Signal Freq Difference voltage lt 2 0 x V step 2 lt 1 3 x V step 4 lt 1 3 x V step 6 Output Impedance Test Broadband Return Loss VSWR lt 2 0 1 Return Loss VSWR lt 1 3
603. t does Then repeat steps 2 through 4 4 44 FM DISTORTION TEST SPECIFICATION FM Distortion at 400 Hz and 1 kHz rates lt 1 for deviations up to 1 8 maximum allowable lt 3 for maximum allowable deviation DESCRIPTION The Signal Generator is modulated with a 1 kHz signal The generators RF output is then demodulated with an FM discriminator and the distortion on the discriminator output is measured with a spectrum analyzer 4 79 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 44 FM DISTORTION TEST Cont d MODEL 8640B OPTION 004 EM 12 DISCRIMINATOR us i eae 9 Q a RF OUT OUTPUT TRUM ANALYZI UDIO SPEC ER Figure 4 29 FM Distortion Test Setup EQUIPMENT FM Discriminator HP 5210A Filter Kit For Discriminator HP 10531A Audio Spectrum Analyzer HP 141T 8552B 8556A PROCEDURE 1 Connect equipment as shown Figure 4 29 after setting Signal Generator s controls as follows Meter Function FM COUNTER MODE EXPAND ro r i r Off LOCK Off Source AM OFF MODULATION FREQUENCY 1 kHz Fixed FM PEAK DEVIATION 80 kHz PEAK DEVIATION Vernier Fully CW RANGE 20 s s s s s 8 6 MHZ FREQUENCY 8MHz OUTPUT LEVEL Switches
604. t voltage with the internal divided down reference voltage and drives transistor Q2 which in turn drives the Series Regulator Transistor Q1 chassis mounted to regulate the current through it Current foldback is activated when the voltage across and hence the current through R25 and R26 exceeds the voltage across R19 The base to emitter junction between pins 1 and 10 of U1 see note on schematic is then forward biased which reduces the drive to the Series Regulator transistor As shown in Figure 8 70 short circuit current is quite low The output crowbar consisting of Q1 VR6 R23 and R24 protects against over voltage outputs due for example to a shorted series pass transisLor An output voltage greater than about 6 2V triggers Q1 which conducts and causes current foldback or blows Fi Lightemitting diode DS2 is on only if the output voltage is high enough to allow CR5 to conduct but not high enough to activate the crowbar Diode CR3 prolects the regulator against reverse polarity load voltages Diode CR4 protects Q1 against reverse bias SERVICE SHEET 22 Cont d INCREASING LOAD SHORT CIRCUIT CURRENT OUTPUT VOLTAGE LIMITING CURRENT OUTPUT CURRENT Figure 8 70 Current Foldback 20V Regulator A22 The 20V regulator functions similarly to the 5 2V regulator except that the output voltage is reduced by the voltage divider formed by R5 R6 and R7 and is referenced to the voltage across VR6 A
605. taken to ensure that leakage signals do not reduce the dynamic range of the test setup use double shielded coaxial cable HP 08708 6033 Keep cables in the phase lock path away from cables in the measurement path Reference Signal Generator HP 8640A 20 dB Amplifier 3 d 2 s s s HP 8447A 10dB Step Attenuator qs y HP 355D Calibrated Step Attenuator HP 355D Option H36 Digital Voltmeter 3480D 3484A Spectrum Analyzer HP 141T 8552B 8553B Tracking Generator HP 8443B Mixer 3 required o HP10514A 4 MHz Low Pass Filter LPF 2 required PE CIR Q TEL 3 Pole 1 5 MHz Low Pass Filter LPF CIR Q TEL 3 Pole Oscilloscope HP 180A 1801A 1820C 20dB Attenuator HP 8491A Option 20 13 dB Attenuator HP 8491A Option 10 and Option 03 Power Meter HP435A 4 39 Performance Tests PERFORMANCE TESTS 4 26 OUTPUT LEVEL ACCURACY TEST Complete Cent d Power Sensor Double Shielded Cable 17 required Noise Filter SPST Switch 100 Resistor 100uF Capacitor 4 40 Model 8640B Option 004 8482 HP 08708 6033 HP3101 0163 HP 0757 0465 HP 0180 0094 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 26 OUTPUT LEVEL ACCURACY TEST Complete Cont d MIXER F
606. ted INFORMATION 1 5 Deleted 1 6 SPECIFICATIONS 1 7 Instrument specifications are listed in Table These specifications are the performance standards or limits against which the instrument can be fest Pars orb 119 lists some supple mental performance characteristics Supplemental characteristics are not specifications but are typical characteristics included as additional information for the user 1 8 INSTRUMENTS COVERED BY MANUAL 1 9 This instrument has a two part serial number The first four digits and the letter comprise the serial number prefix which defines the instrument configuration The last five digits form the sequen tial suffix that is unique to each instrument The contents of this manual apply directly to instru ments having the serial prefixes 1435 and 1438A 1 10 An instrument manufactured after the print ing of this manual may have a serial prefix that is different from that indicated above If 80 refer to Section make the applicable manual changes 1 11 Deleted 1 1 General Information 1 12 For information concerning a serial number prefix not covered in this manual contact your nearest Hewlett Packard office 1 13 GENERAL DESCRIPTION 1 14 The Model 8640B Option 004 Signal Gener ator is an adaptation of the Model 8640B specifi cally designed for testing ILS VOR and UHF communications receivers used in aviation as well as general Purpose HF VHF and UH
607. ted Pull the handle marked FUSE PULL and remove the fuse rotate the handle to the left Gently pull the printed circuit voltage selector card from its slot and orient it so that the desired operating voltage appears on the top left side Figure 2 1 8120 1378 8120 1351 8120 1369 8120 1689 Model 8640B Option 004 Firmly push the voltage selector card back into its slot Rotate the FUSE PULL handle to the right install a fuse of the correct rating and slide the fuse compartment cover to the right A complete set of fuses is supplied with the instrument see ACCESSORIES SUPPLIED in Section NOTE The correct fuse rating for the line voltage selected is listed on the line power module More information about fuses is given in the table of replaceable parts if Section YI reference designa tion is F1 2 11 Power Cable 2 12 In accordance with international safety standards this instrument is equipped with a three wire power cable When connected to an appropriate power line outlet this cable grounds the instrument cabinet The type of power cable plug shipped with each instrument depends on the country of destination Refer td Figure 2 2 for the part numbers of the power cable plugs available Figure 2 2 Power Cables Available 2 2 Model 8640B Option 004 To avoid the possibility of injury or death the following precautions must be followed before the instrument is switched on a If thi
608. the A8A1 RF Scaler Board Assembly If resistors R12 R13 and R14 are in the circuit remove them and install a jumper in place of R13 2 If the counter displays erratic readings in the EXT 550 mode it maybe necessary to change A8A1R7 or add attenuator pad A8A1R12 14 3 If the malfunction occurs at input levels less than 0 dBm change A8A1R7 to 68 1 ohms Continued 7 20 Model 8640B Option 004 08640 90073 ERRATA Cont d 4 If the malfunction occurs at input levels greater than 0 dBm add A8AIR12 14 according the the following table rar me dBm or greater NOTE Newer versions of the RF Scaler Assembly A8A1 have printed circuit pads provided for resistors R12 R13 and R14 In older versions it may be desirable to replace some components with solder posts and wire the new circuitry to the posts Page 5 3 Table 5 1 We the following additions to the table Component Service Sheet Range of Values Basis of Selection A8A1R7 18 51 or See paragraph 5 21 68 1 2 ASAIRI2 ASATRI3 18 See paragraph 5 21 ASAIRIA Page 5 34 Paragraph 5 40 Change the table in step 8 to read as follows PEAK DEVIATION DVM Raading at A7TP3 2 56 MHz lt 5 6 mVdc 1 28 MHz lt 5 6 mVdc 640 kHz lt 5 6 mVdc 320 kHZ lt 5 6 mVdc 160 kHZ 4 5 mVdc 80 kHz lt 2 2 mVdc 40 kHz t 1 1 mVdc 20 kHz lt 0 6 10 kHz lt 0 6 mVdc 5 kHz t 0 6 mvdc Page 6 2 Table 6 1 Delete en
609. the lamp logic circuits on A4 Service Sheet 17 Switch A1S1 provides additional 1 dB steps for attenuating the RF LEVEL meter voltage 8 50 Model 8640B Option 004 OUTPUT LEVEL Vernier Modification OUTPUT LEVEL Vernier A1R1 is normally wired to provide additional attenuation 0 2 dB to the AGC reference voltage and the superimposed AM modulation signal The potentiometer has a CAL detent where the wiper is fully clockwise and the potentiometer is effectively removed from the circuit However for some applications it may be desirable to disable the vernier function so that the OUTPUT LEVEL will always be calibrated To modify the OUTPUT LEVEL Vernier function proceed as follows 1 Remove the bottom cover see Service Sheet G 2 Locate variable resistor A1R1 3 Unsolder and remove wire 90 white black from the center terminal of R1 4 Connect and solder wire 90 to wire 4 yellow on the top terminal of R1 5 Reinstall bottom cover 6 Check OUTPUT LEVEL Vernier operation by observing OUTPUT LEVEL which should re main constant as the vernier knob is adjusted TROUBLESHOOTING Troubleshoot by checking switches connectors and resistors for proper contact and resistance Modet 060406 Uption 004 Figure 8 54 A19A2 RF Vernier Assembly Component Locations A26 AND RF AMPLIFIER ASSY 08640 60058 P O A19 10 dB OUTPUT LEVEL ASSY 08640 60060 __ P O 26 6 AM MOTHE
610. the same level with respect to the center reference graticule line as tie last recorded entry on the previous table 4 37 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 25 OUTPUT LEVEL ACCURACY TEST Abbreviated Cent d 10 Set Signal Generator and analyzer controls as shown in the following table The amplitude levels should be within the specified tolerances If necessary use generators OUTPUT LEVEL 1 dB switch and vernier to reset panel meter to 1 dB Signal Generator Spectrum Anal yzer RF Level Set Log Reference Output Level 10 dB with Panel Level Control dB Meter dB Display Amplitude 10 steps ccw Set Level 11 steps ccw 2 5 12 steps ccw 2 5 13 steps ccw 2 5 14 steps ccw 2 5 11 Set analyzer s display to 10 dB division log Adjust log reference level vernier to set signal to 10 dB graticule line one major division from top of display plus last recorded entry on previous table NOTE If the following step appears to be out of specification check the accuracy of the analyzer s display with an external calibrated attenuator 12 Set Generators OUTPUT LEVEL 10 dB switch one step ccw to dBm The amplitude level indicated on analyzer s display should be within 2 5 dB of the 20 dB graticule line second major division from top of display 22 5 17 5 dB NOTE The noise level on the analyzer s display should be gt 10 dB below the signal level The signal should drop into
611. ting Change 6 7 9 7 51 A8A1 RF Scaler Assembly C mbougnt Locations Backdating Change H 4 7 10 22 20V and 20V Regulator Assembly Component Locations Change I A 712 Power Supply Circuits Backdating Change D 7 1 A22 20V and 20V Regulator Assembly Backdating Change D 1 9 Modified Line Switch Wiring 7 18 Signal Generator with Circuit Boards on Extenders Sox 82 Examples of Diode and Marking Methods us m Open Collector Output Stage AND Gate 8 8 Binary Symbols riggered Flip Flop 8 7 Flip Flop 18 7 Schmitt Trigger B8 yk Flip Flop E5 Multiple Input J K Flip Hop 8 10 _ 1 Latch Binary Shift Register EDT asic Decade Counter Scale TT 1 ojlo oo 3 1 Programmable Counter 2 8 10 Era Up Down Cotinter X 8 12 amp 5 Operational Amplifier 8 13 8 16 Comparator 2 L814 EIZ bimplified Block 8 19 EU Mo Block Diagram 2 J 8 19 Circuits and RF Oscillator Block Diagram 8 21 8 20 JAM AGC Circuits and Output Julliet Block Diagram 8 21 Counter Lock Circuits Block Dineren E 8 22 P O A3A4 Connector Board Assembly Component Locations 8 27 8 23 RF Oscillator Simplified Diagram 2 BZ 8 24 P O A3A4 Connector Board Assembly Component Locations 8 28 P O A9 Peak Deviation and
612. ting bottom cover to the casting WARNING The RF I gasket on casting cover may have sharp edges and may cause personal injury if not handled with care 8 80 Model 8640B Option 004 Lift cover from casting noting the orientation of the RFI gasket under the cover NOTE Do not attempt to replace components on the A26A1 and A26A3 assemblies without removing them 2601 and A26U2 Removal 10 11 12 Remove two pan head screws with washers that secure microcircuit amplifier A26U1 or U2 to casting Remove 2601 or U2 Remove four pan head screws with lock washers that secure the heat sink to the casting Remove pan head screws with lockwashers that secure the circuit board to the casting Disconnect two coaxial cables from casting connectors Remove nuts and washers that secure cable connectors to casting To replace components mounted on the cir cuit board tilt the board up while sliding it to the rear To replace or remove the circuit board label the wires soldered to the board before un soldering them Reassemble by reversing procedures in steps one through twelve Model 8640B Option 004 Service SERVICE SHEET F Cont d a A26 AM AGC and RF Amplifier Assembly Legend uam Reference 1 A26C1 2 5 12 C15 16 Feed Thru Capacitor 2 A26C17 18 Feed Thru Capacitor 3 A26C3 4 14 Feed Thru Capacitor 4 A26C13 Feed Thru Capacitor 5 A26R1 Resistor 6 A26U
613. tions Internal Modulation Omit test Excessive distortion will usually manifest itself Oscillator Distortion in AM and FM distortion tests Test Option 001 AM 3 dB Bandwidth Omit test Accuracy at most often used frequencies Test checked in AM 22 2 test ML Distortion Test Distortion Test AM Sensitivity and Omit step Lm but A spot check of meter accuracy is a Accuracy Test check meter in adequate steps 1 to 7 Peak Incidental Phase Omit test Test requires access to inside of instrument Modulation Test Specification does not normally degrade with time Demodulated Output None Accuracy Test AM Phase Shift Test Omit test A condition that is out of specification will show up on the AM Flatness Teat also AM Flatness Test Test Ne Pulse Modulation Test steps 7 to 8 Performance I improves at the higher frequencies Pulse On Off Ratio Test omit step 4 Performance usually improves at the lower frequencies FM 3 dB Bandwidth Omit test Accuracy at most often used frequencies Test checked in FM sensitivity test FM Sensitivity and Omit steps 6 to 9 A spot cheek of meter accuracy is usually Accuracy Test but check meter adequate in steps 1 to 5 4 3 Performance Tests Model 8640B Option 004 Table 4 1 Recommended Test Abridgements 3 of 3 Incidental AM Test Omit test Incidental AM usually of secondary importance and FM sensitivity test will usually show condi tions that
614. tire entry for 8 1 Under A8A2 change Exchange Assy part number to 08640 60187 Page 6 6 Table 6 1 Change A2VR2 to 1902 3104 DIODE ZNR 5 6V 5 DO 7 PD 0 4W A3MP9 and A3MP13 The single recommended replacement for both parts is 08640 20267 see Change 14 The recommended replacement for is transistor 5086 4282 see Change 11 7 21 Model 8640B Option 004 08640 90073 ERRATA Cont d Page 6 11 Table 6 3 A7R28 and A7R45 The recommended replacement for A7R28 is 0757 0465 and for A7R45 is 0698 3159 NOTE For instruments not already modified as above it will be necessary to replace both A7R28 and A7R45 the first time that either resistor is replaced see Change 16 Page 6 13 Table 6 3 Change A8U1 U6 to 1990 0507 Change A8A2 08640 60087 to 08640 60187 RESISTOR 08640 60027 60189 or 60258 REQUIRES EXCHANGE Page 6 15 Table 6 3 A8A2U20 24 and U28 The recommended replacement for A8A2U20 24 and U28 is 1820 1684 see Change 16 Page 6 1 Table 6 3 A8A3U10 U11 and U13 thru U17 Recommended replacements for these parts and associated resistors A8A3R10 and R17 are presented in Change 15 Page 6 4 Table 6 3 Add HP Part Number 08640 60103 for J1 MP29 The recommended replacement for MP29 is coupler 1500 0433 see Change 7 Table 6 3 Add MP81 08640 00037 INSULATOR BOTTOM COVER MP82 Added in Change 7 Add MP83 3030 0343 SCREW SET 1 4 28 0 25 in lg HALF DOG PT NOTE Reference
615. tment if necessary 5 34 VT Voltage Adjustment 5 36 RF Filter Adjustment if necessary 5 39 Adjustments Model 8640B Option 004 Table 5 2 Post Repair Test and Adjustments 3 of 4 Assembly Repaired Performance Tests Fixed Frequency Internal Modulation Oscillator Modulation Oscillator Assy Test 4 32 or Internal Modulation Oscillator Distortion Test Option 001 Variable Frequency only 4 33 y 4 Modulation Oscillator Assy Option 001 A12 Rectifier Assy Frequency Stability vs Time A13 Modulation Metering Test 4 15 Mother Board Assy Frequency Stability vs Line A14 Line Power Module Voltage Test 4 17 15 Riser Assy Residual FM Test 4 24 Internal Reference Drift A17 Power Supply Mother Board Assy Rate Stability Test 4 49 A20 5 2V and 44 6V Regulator Assy A22 20V and 20V Regulator Assy A24 Series Regulator Socket Assy A16 Fan Motor Assy Residual FMTest 4 24 18 52 Regulator and Fan Driver Assy A19 10 dB Output Level Assy Harmonics Test 4 19 Output Level Accuracy Test 4 25 or 4 26 Output Level Flatness Test 4 27 Output Impedance Tests 4 28 or 4 29 Output Leakage Test 4 31 A26 AM AGC and RF Harmonics Test 4 19 Amplifier Assy Residual AM Test 4 23 Output Level Accuracy Test 4 25 or 4 26 Output Level Flatness Test 4 27 5 6 Adjustments Check power supply voltages 5 25 Fixed Frequency Modulation
616. tmeter to DEMOD OUTPUT With the MODULATION control set percent AM as follows The voltmeter should indicate approximately as shown for the appropriate AC DC switch selection 400 mVrms 200 mVrms 600 mVrms 300 mVrms 800 mVrms Figure 3 5 Operator s Checks 5 of 5 3 12 Model 8640B Option 004 Operation SETTING FREQUENCY AND AMPLITUDE Frequency a Set COUNTER MODE to INT and TIME BASE VERNIER to CAL Set RANGE to span the desired frequency Use FREQUENCY TUNE and FINE TUNE to set the Signal Generator to the desired frequency The decimal point on the FREQUENCY display is automatically set by the RANGE control B For more resolution set COUNTER MODE EXPAND to X10 or X100 To phase lock the generator s output set COUNTER MODE LOCK to ON use TIME BASE VERNIER as the fine frequency tune On some frequency bands it will be necessary to use the COUNTER MODE EXPAND controls to tune between adjacent counts NOTE If the OVERFLOW annunciator lamp lights the generator will not enter calibrated phase lock If the TIME BASE VERN is not in the CAL position the counter will not be calibrated Figure 3 6 Setting the Frequency and Amplitude Controls 1 of 3 3 13 Operation Model 8640B Option 004 SETTING FREQUENCY AND AMPLITUDE Whenever phase lock is lost the FREQUENCY display will flash To re establish phase lock set COUNTER MODE LOCK to OFF re tune if necessary with FREQUENC
617. to 3 dB scale is read relative to the dBm scales on the OUTPUT LEVEL dials Output Problem Annunciators lamps light to indicate that modulation or OUTPUT LEVEL settings are causing generator to be uncalibrated SCALE annunciator lamps light to indicate ap plicable meter scale Meter scale is automatically selected Meter automatically ranges to one of three scales read according to meter function 3 2 AM X 10 0 3 scale is read 0 30 0 10 scale is read 0 100 FM kHz MHz 0 3 0 5 and 0 10 scales are read in kHz or MHz depending upon setting of PEAK DEVIATION switch e g with REDUCE PEAK POWER indicates a com bination of OUTPUT LEVEL and amplitude modulation that exceeds specified limits 1 100 on all RF frequency ranges except 256 512 MHz and typically greater than 50 AM on this top range REDUCE FM VERNIER indicates that an external FM input level or vernier setting is causing FM deviation to exceed limits Figure 3 2 Front Panel Controls Indicators and Connectors 1 of 4 Model 8640B Option 004 Operation FRONT PANEL FEATURES REDUCE PEAK DEVIATION v indicates PEAK DEVIATION setting is too high for the selected frequency range COUNTER MODE Buttons control operation of frequency counter EXPAND X10 expands resolution one digit moving the decimal point one place to the left X100 expands resolution two digits moving the decimal point two places to the left
618. top band frequency is made low enough to suppress the second harmonic In the higher portion of the band a filter with a higher stop band frequency is switched in to suppress the second harmonic The high band filter is switched in at approximately the geometric mean of the frequency extremes of the band A Schmitt Trigger senses a dc voltage VT which is proportional to the fre quency and relays switch the filters at the geometric mean On the four lowest bands the low band filter for the 16 32 MHz range is also switched in series with the band filters to improve the re jection of high order harmonics All range switching is done by cam operated slide switches on the filter board A10A1 The filters drive the output amplifier which drives the RF output and AGC circuits The filters are inside the AGC feedback loop RF Filters A10A1 The AIOA1 RF Filter Assembly contains sixteen RF lowpass filters and six slide switches that are controlled by the RANGE switch The filters for the four lowest bands 0 5 8 MHz bands are sharp cutoff elliptic f unction filters The remaining filters are Chebishev filters In the six highest bands relays K1 and K3 switch in the low band filters when the frequency is below the geometric mean frequency of the range and relays K2 and K4 switch in the high band filters when above the geometric mean The slide switches route the RF signal to the proper filters activate the frequency dividers and route the RF si
619. tors 1 47 For narrowband FM applications a mini mum full scale deviation of 5 kHz is provided on the meter and the PEAK DEVIATION range switch When switching from the CWto FM mode there is negligible shift in carrier frequency and no degradation in spectral purity for these narrow deviations With the generator in the phase lock mode it is possible to modulate at rates down to 50 Hz while maintaining accurate FM calibration and the carrier drift stability of a crystal oscillator Using the unlocked mode it is possible to modul ate from dc to 250 kHz with a carrier drift stability of 10 ppm 10 min 1 48 Standard and Optional Audio Oscillators 1 49 Standard tones for internal modulation are 400 Hz and 1000 Hz These tones are also available at the front panel and can be varied in output level from 1 V to 10 mV into 600 Total harmonic distortion is typically 0 2596 1 50 Optionally available on the Signal Generator is a built in variable frequency oscillator covering the range 20 Hz to 600 kHz fixed tones of 400 Hz and 1000 Hz are also provided This internal oscillator has a wide range of standard modulation frequencies and is useful for testing receiver audio bandwidth Output from this modulation souce is General Information available separately at the front panel and can be varied in level from 3V to 20 mV into 600 Q This audio oscillator Option 001 extends the usable CW range of the generator down to
620. trols for a to 5 kHz span Set the display for 10 dB per division 5 Use generator s PEAK DEVIATION vernier to set 5 kHz of peak deviation as read on panel meter Use analyzer s display reference level controls to set the demodulated 1 kHz signal to the top reference graticule line on the display 6 Adjust POS SHAPE and NEG SHAPE adjustments A7R12 and A7R41 for minimum distortion Observe both second and third harmonics 7 Slowly tune from 0 5 to 1 MHz and observe distortion If harmonics are less than 30 dB down 396 distortion or if it is desired to minimize distortion across the band adjust A7R12 and A7 R41 for best compromise However harmonics must always be greater than 30 dB down 8 Perform the FM sensitivity adjustment 5 43 5 43 FM SENSITIVITY ADJUSTMENT REFERENCE Service Sheets 6 and 7 DESCRIPTION The Signal Generator is frequency modulated with an accurate 1 Vpk 16 63 kHz signal The modulated RF output is monitored on a spectrum analyzer and FM sensitivity is adjusted for the first carrier Bessel null The adjustments are made at mid band and at both band ends Peak deviation 2 405 x fmod at first carrier null NOTE The FM Linearity Adjustment 5 41 or 5 42 should be made before performing this adjustment 5 40 Model 8640B Option 004 ADJUSTMENTS 5 43 FM SENSITIVITY ADJUSTMENT Cont d VARIABLE PHASE GENERATOR MODEL 86408 OPTION 004 EQUIPMENT PROCEDURE IM
621. ts 5 10 48 to 440 Hz 175 VA maximum 2 29m 71 ft power cable furnished with mains plug to match destina tion requirements Weight Net 21 3 kg 47 Ib Dimensions NOTES DIMENSIONS IN MILLIMETERS AND INCHES Qua RACK HEIGHT INCLUDING FILLER STRIP FOR CABINET HEIGHT FNI FEET ADD my 8 15 18 TO FIA RACK REAR APRON RECESS Ie 425 5 16 34 476 3 255 1 Dimensions are for general information only If dimensions are required for building special enclosures contact your HP office 1 13 General Information Model 8640B Option 004 Table 1 2 Recommended Test Equipment 1 of 6 instrument Type Critical Specifications Suggested Model Adjustable Stub Length gt 50 cm GR 874 D50L Range to 550 MHz HP 8447A P 8447B 20 dB Amplifier 3 required Range 0 5 520 MHz Gain 20 to 25 dB Flatness over Range 2 dB Impedance 50Q Noise Figure lt 5 dB 20 dB Amplifier Range 400 1200 MHz Gain gt 20 dB Flatness 2 dB Impedance 502 Noise Figure lt 5 dB to 1 GHz 40 dB Amplifier Range 5 Hz to 100 kHz Gain 20 and 40 dB 1 dB Input Impedance gt 5kQ Output Impedance 500 Noise lt 25 uVrms referred to input Output 71 Vrms into 500 40 dB Amplifier Range 20 Hz to 100 kHz HP 08640 60506 Gain 40 1 dB Input Impedance 5022 Noise Figure 3 dB when driven from 5
622. tween 0 and 3 dB and the vernier is CAL detent As output attenuation is increased the meter reading decreases i e the needle moves to the left and output voltage Figure 3 6 Setting the Frequency and Amplitude Controls 2 of 3 3 14 Model 8640B Option 004 Operation SETTING FREQUENCY AND AMPLITUDE is read on the indicated voltage scale At approximately 1 on the 0 3 scale or 3 on the 0 10 scale the meter autoranges to the next lower range The vernier provides additional attenuation and also affects meter autoranging If a 50 ohm to 75 ohm adapter consisting of a 25 ohm series resistor is connected to RF OUT the Output Level voltage scale will be correct if the instrument is used with 75 ohm terminations However 1 76 dB must be subtracted from the dB scale for correct readings Figure 3 6 Setting the Frequency and Amplitude Controls 3 of 3 3 15 Operation Model 8640B Option 004 SETTING MODULATION Amplitude Modulation Set Meter Function to AM To use the internal modulation oscillator set AM to INT Set MODULATION FREQUENCY to the desired frequency and set percent of modulation with the MODULATION vernier 6 modulation is indicated by the meter c a meter reading of 5 4 indicates that the AM is 54 NOTE The REDUCE PEAK POWER annunciator lights whenever the Signal Generator s output amplifier is being overdriven When it lights reduce MODULATION vernie
623. uency at RF OUT an amount equal to the desired peak deviation Set FM to DC or AC a 1 Vpk 0 7071 Vrms signal applied to FM INPUT will now produce the desired peak deviation Do not use FM CAL when phase locked Figure 3 7 Setting the Modulation Controls 4 of 5 3 19 Operation Model 8640B Option 004 SETTING MODULATION NOTES 1 The REDUCE FM VERNIER annunciator 0 lights whenever an FM input causes peak deviation to exceed its limits When it lights reduce either the PEAK DEVIATION vernier or the external signal level 2 Do not apply FM signals that are less than 50 Hz when using the generator in the phase lock mode Doing so will cause either the FM deviation to be uncalibrated or the generator to break phase lock thereby causing the counter display to flash Also do not use FM CAL after locking Simultaneous AM and FM Simultaneous AM and FM or pulse modulation and FM can be accomplished using the procedures described above The internal modulation oscillator can be used for either one or both AM and FM m NOTE On Signal Generators with the Option 001 Variable Modulation Oscillator don t load both AM OUTPUT e and FM OUTPUT when the oscillator is providing both modulating signals The outputs are in parallel and the parallel load should be greater than 600 ohms Figure 3 7 Setting the Modulation Controls 5 of 5 3 20 Model 8640B Option 004 Performance Tests SECTION IV PERFORMANCE TE
624. ument Upside Down Spurious Test Setip RF Oscillator Output Power Adjustment 4 6 Single sideband Phase Noise Test Setup 4 25 Test Setup ES Single sideband Broadband Noise 58 Fiter Terminology Floor Test Setup 5 9 Filter Adjustment Test Setup 5 30 4 8 Residual AM Test Setup TPS 56 512 MHz High Band Capacitor 4 9 Residual FM Test Setup i Adjustment Orientation 4 10 Output Level Accuracy Test Setup 15 11 JFM Linearity Adjustment Test Setup 5 36 Abbreviated 15 12 Linearity Display 5 38 411 E i Test Setup Idi 5 13 FM Linearity Adjustment Alternate ompiete E Mi Test Setup 4 12 Output Level Flatness Test Setup e 5 4 Sensitivity Adjustment Test Setup 413 Output Impedance Test Setup 5 15 Internal Reference Signal Frequency i Test Setup E 4 14 Dutput Impedance Test Broadband 14 49 4 15 Qutput Leakage Test Setup 4 5 4 16 Internal Modulation Oscillator Test 6 I Cabinet Parts 222220202 setup 4 54 6 2 Connector 6 44 Model 8640B Option 004 Table of Contents ILLUSTRATIONS cont d Figure Page A26A2 AM Offset and Pulse Switching Assembly Backdating Change C 4 22 7 6 7 21 A12 Rectifier Assembly Component Backdating Change 12 Rectifier Assembly Backdating Change 7 4 A3A4 Connector Board vies Backda
625. ut Level Checks Refer to step 1 for initial control settings a Set RANGE to 128 256 MHz FREQUENCY TUNE to 190 MHz and Meter Function to LEVEL Connect a power meter to RF OUT and set OUTPUT LEVEL for a front panel meter indication of 9 dBm 10 1 The power meter should read between 7 5 and 10 5 dBm Reduce OUTPUT LEVEL to 3 dBm as read on the panel meter The power meter should read between 1 5 and 4 5 dBm Return OUTPUT LEVEL to 9 dBm as read on the power meter Tune across all frequency bands for which the power sensor is specified and note maximum and minimum level variations The level should be between 8 5 and 49 5 dBm for frequencies between 108 and 336 MHz between 8 25 and 49 75 dBm for other frequencies between 0 5 and 512 MHz AM and Pulse Checks Refer to step 1 for initial control settings a Set RANGE to 64 128 MHz FREQUENCY TUNE to 108 MHz and OUTPUT LEVEL to 40 dBm Connect RF OUT to the input of a spectrum analyzer Set analyzer controls to display the 108 MHz signal with 10 kHz or greater resolution bandwidth linear vertical scale 5 to 20 KHz of display smoothing and zero frequency span width Check that the signal is peaked on the display and adjust the vertical sensitivity for 4 divisions of deflection It is also good to ensure that the base lime with no signal is at the bottom line of the display Set AM to INT and Meter Function to AM Adjust MODULATION for a panel meter reading o
626. utput Level Accuracy Test Check power supply voltages power meter steps 5 25 4 25 or 4 26 Output Level Flatness Test 4 27 Output Leakage Test 4 31 AZ Meter Switch Detector Output Level Accuracy Test Check power supply voltages Assy 16 and 10 dBm ranges 5 25 A4 Meter Annunciator Drive only 4 25 or 4 26 Meter Adjustments 5 28 Assy AM Sensitivity and Accuracy Panel Meter MI Test meter only 4 36 FM Sensitivity and Accuracy Test meter only 4 45 A3 RF Oscillator Assy Frequency Range Test Check power supply voltages 256 512 MHz only 4 13 5 25 Frequency Accuracy and Fine VT Pot Adjustment 5 35 Tune Test fine tune only VT Voltage Adjustment 5 36 4 14 RF Oscillator Output Power Frequency Stability Tests Adjustment if necessary 4 15 4 16 4 17 and 4 18 5 38 Harmonics Test 4 19 Preliminary FM Adjustments Single Sideband Phase Noise if necessary 5 40 Test 4 21 FM Linearity Adjustment Residual FM Test 4 24 if necessary 5 41 or 5 42 Output Level Flatness Test FM Sensitivity Adjustment 256 512 MHz only 4 27 if necessary 5 43 Output Leakage Test 4 31 FM Distortion Test 4 44 FM Sensitivity and Accuracy Test 4 45 Phase Lock Restabilization Time Test check only that phase lock operates 4 50 AS FM Amplifier Ass y FM 3 d B Bandwidth Test 4 43 Check power supply voltages A7 FM Shaping Assy FM Distortion Test 4 44 5 25 FM Sensitivity and Accuracy Pr
627. ve adjustable stub note frequency counter reading then set OUTPUT LEVEL 10 dB switch one step ccw Again note frequency counter reading It should have changed less than 512 Hz 512 Hz 4 With FM switch set to OFF note the frequency counter reading Set PEAK DEVIATION switch to 10 kHz and PEAK DEVIATION vernier fully clockwise Set FM to AC and again note frequency counter reading It should have changed less than 200 Hz 200 Hz 5 Repeat step 4 with PEAK DEVIATION set as shown below The frequency change should be as specified peak Deviation Frequency Change 200 Hz 400 Hz 800 Hz 1 6 kHz 3 2 kHz 6 4 kHz 12 8 kHz 25 6 kHz 4 19 HARMONICS TEST SPECIFICATIONS Harmonics on 1V 10 dBm output range and below gt 35 dB below fundamental of 0 5 to 128 MHz 230 dB below fundamental of 128 to 512 MHz DESCRIPTION A spectrum analyzer is used to measure harmonics as the Signal Generator is tuned from 0 5 to 512 MHz EQUIPMENT Spectrum Analyzer HP 141T 8552B 8554B 4 21 Performance Tests Model 8640B Option 004 PERFORMANCE TESTS 4 19 HARMONICS TEST Cont d PROCEDURE 1 Connect generators RF OUTPUT to analyzer s input after setting Signal Generator s controls as follows Meter Function LEVEL COUNTER MODE off LOCK 5x23 555 oe om SOUCE 2 uo we ah ede v RU Rmo cer INE FM OFF RANGE 2 ah Bp ah etos t dre d
628. ve specification in the 5 kHz PEAK DEVIA TION range If the FM Amplifier is peaking excessively increase the value of A9C8 until flatness of the amplifier is within specification d A1OA2R3 Selection If A10A2U11 or 012 is replaced and RF output irregularities are observed it may be necessary to change the value 5 2 Model 8640B Option 004 of A10A2R3 Select the proper value as follows l Observe the RF OUT signal with a spectrum analyzer 2 Set RANGE to 64 128 MHz 3 Adjust FREQUENCY TUNE across the band 4 If signal irregularities e g erratic fre quency sub harmonics or increased level of the noise floor are observed increase the value of AIOA2R3 within the range of values shown in Table 5 1 e A10A2R6 8 R12 14 and R18 20 Selec tion If 2602 Service Sheet 12 has been re placed check second harmonic level at RF OUT jack on the following bands 128 256 MHz 64 128 MHz and 32 64 MHz If second harmonic level is out of specification increase affected band s divider output attenuation until second harmonic level is within specification The follow ing table indicates correct values of resistance for 3 to 6 dB of attenuation change attenuation in 1 dB steps Band RANGE Resistors 2 128 256 MHz R7 R8 64 128 R13 R14 32 64 R18 R19 R20 Resistance Attenuation f To change attenuation change all three resistors associated with the band that s out of specificatio
629. verse voltage wirewound without yttrium iron garnet characteristic impedance MODEL 8640B OPTION 004 REPLACEABLE PARTS TABLE 6 3 REPLACEABLE PARTS REFERENCE HP PART QTY DESCRIPTION MFR MFR PART NUMBER DESIGNATION NUMBER CODE 1 08640 60062 1 OUTPUT LEVEL 55 1DB 28480 08640 60062 1 08640 60077 RESTORED 08640 60062 REQUIRES EXCHANGE 28480 08640 60077 1 0380 0020 3 SPACER RND 25 LG 128 ID 1880 OD BRS NI 76854 2295 616 1 2 0380 0023 1 SPACER RND 5 LG 128 ID 19 OC STL 76854 3457 432 1 0380 0029 1 SPACER RND 1 16 128 ID 19 OD STL CD AU 76854 3457 464 1 4 2200 0781 1 SCREW MACH 4 40 PAN HD POZI REC 55 300 28480 2200 0781 1 5 3130 0038 1 COUPLES SWITCH SST U SHAPED 76854 12276 6 1 6 08640 00068 1 PLATE MCUNTING 08480 08640 00068 1 7 08640 20235 1 SHAFT VERNIER 28480 08640 20235 1 8 08640 20236 1 SHAFT VERNIER 28480 08640 20236 1 9 2190 0003 4 WASHER LK HLCL 4 115 IN ID 253 28480 2190 0003 1 10 2190 0016 3 WASHER LK INTL T 377 IN ID 507 IN OD 78189 1920 02 1 11 2360 0120 2 SCREW MACH 6 32 82 DEG FL HD POZI REC 2840 2360 0120 1 12 2950 0001 1 NUT MEX DBL CHAM 3 8 32 THD 094 5 12697 20 4 13 1251 0198 3 CONNECTOR PC EDGE 6 CONT SOLDER EYE 71785 251 06 30 261 1 1 2100 0638 1 RESISTOR VAR 250 OHM 20 28480 2100 0638 A1R2 0698 4197 1 RESISTOR 1 081K 25 125W F TUBULAR 03888 PME55 1 8 T0 1081R C A
630. vice Sheet 16 schematic Delete resistors A19A2R7 and R8 and associated wiring On switch AI9SIBF R connect switch terminals 7 and 9 to terminal 6 CHANGE 12 Page 6 14 Table 6 3 Add A8A2C27 0140 0205 CAPACITOR FXD 62 5 300WVDC MICA Page 6 13 Table 6 3 Change A8A2U6 and U25 to 1820 1322 IC SN74S02N GATE Service Sheet 20 Schematic Add C27 62 pF between A8A2U13D pin 11 and ground Change A8A2U6 and U25 to 1820 1322 CHANGE 13 J Table 6 3 Change A1OA2UI to 1826 0303 Service Sheet 11 schematic Change part number for AIOA2UI to 1826 0303 CHANGE 14 Page 5 3 Table 5 1 Delete A11R28 Option 001 Pages 5 P and 5 11 paragraph 5 2 Under EQUIPMENT add the following instruments Distortion Analyzer HP333A Oscilloscope 2 2 2 2 2 2 2 HP 180A 1801A 1820C Change step 12 to read as follows 12 If level at is too high adjust 11 28 reduce resistance if level is too low adjust A11R28 cw increase resistance Then repeat steps 8 through 11 Add the following steps after step 16 16a Set MODULATION FREQUENCY controls to 600 kHz Connect distortion analyzer to front panel AM OUTPUT connector Calibrate distortion analyzer and measure distortion Distortion analyzer should indicate leas than 2 166 Set MODULATION FREQUENCY controls to 20 Hz Connect oscilloscope to AM OUTPUT connector Set AM switch alternately between O
631. wn in parentheses d Location The physical location of each item listed is given in this column The lists are designed to inventory all items in one area of the major item before moving on to an adjacent area e Usable on Code Not applicable USABLE ON codes are included to help you identify which component items are used on the different models Identification of the codes usedin these lists are Code Used on f Quantity Required Qty Regal This column lists the quantity of each item required for a complete major item g Quantity This Column is left blank for use during an inventory Under the Rcvd column list the quantity you actually receive on your major item The Date columns are for your use when You inventory the major item Next printed page is B 2 B 1 SECTION II 1 ILLUSTRATION A B FIG ITEM NO NO dos 1 1 INTEGRAL COMPONENTS OF END ITEM 2 NATIONAL STOCK NUMBER 6625 00 566 3067 6625 00 500 6525 3 DESCRIPTION PART NUMBER SIGNAL GENERATOR SG 1 HEWLETT PACKARD MODEL SIGNAL GENERATOR SG 1 HEWLETT PACKARD MODEL LINE POWER CABLE HEWLETT PACKARD P N 6 12 V 1 U 8640B OPTION 12 V 2 U 8640B OPTION 20 1378 SECTION III BASIC ISSUE ITEMS TECHNICAL MANUAL TM 1 4 LOCATION FSCM 004 001 6625 2780 146 5 USABLE ON CODE 6 QTY REQD 7 QUANTITY RCVD DATE TM 11 6625 2780 14 amp P APPENDIX D MAINTENANCE
632. wo holes labeled RF OSC ON OFF INHIBIT as shown overleaf To modify the circuitry so the RF Oscillator is switched off remove the existing jumper wire d Reinstall board and bottom cover Check RF ON OFF operation by observ ing counter or Auxiliary RF Output signal Model 8640B Option 004 Figure 8 22 P O A3A4 Connector Board Assembly Component Locations Service P O A13 P O A3 RF OSCILLATOR ASSY 08640 60099 MODULATION re MELLE MERTERING BOARD P O 4 CONNECTOR ASSY 08640 60057 BOARD ASSY 08640 60196 T eee 1 FILTER BUFFER AMPLIFIER ASSY 08640 60130 _ FREQUENCY COUNTER BUFFER AMPLIFIER BOARD ASSY 08640 80037 mw 20V RI NM FLI V FINE 909 2 2 we T 0 10 tune z 10K a R7 TT 100 R5 909 d i t 1 FILTERIBUFFER AMPLIFIER tmm TIONAL CAVITY 147 RI RH 73 R2 9 aa 21 5 21 5 VARACTOR HEAD FILTER E ii NE 1119 02 C R12 j VARACTOR 1 1854 0247 7 1000 but i VARACTOR HEAD ASSY _ _ Ns 7 Um 2 CATHODE E am 7 10 Pd R8 1 i c2 C5 yu i 1000 16 2 i1 09 69 OSC R9 FL2 7 g _ por 97 INHIBIT 1 i 11 z T VARACIOR HR ae T 2 j
633. xternal ac 20 Hz to 250 kHz External dc de to 250 kHz DESCRIPTION An audio spectrum analyzer is used to measure the 3 dB rate bandwidth The analyzer is set to sweep over the specified audio frequency range and its tracking generator output is used to frequency modulate the Signal Generator The generator s RF output is demodulated with an FM discriminator The demodulated signal is fed to the analyzer s input and any amplitude variation is measured on the analyzer s display Bandwidth is checked at maximum deviation on the 8 16 MHz band See Recommended Test Abridgements MODEL 86408 OPTION 004 FM DISCRIMINATOR AUDIO SPECTRUM ANALYZER TRACKING GEN OUTPUT Figure 4 28 FM 3 dB Bandwidth Test Setup EQUIPMENT Audio Spectrum Analyzer HP 141T 8552B 8556A FM Discriminator HP 5210A Filter Kit For Discriminator HP 10531A PROCEDURE l Connect equipment as shown ip Figure 4 28 after setting Signal Generator s controls as follows Meter Function COUNTER MODE EXPAND er xo Off LOCK Sourte AM ow wow 4 o X x de de amp We We x OFF FM OFF PEAK 80 kHz PEAK DEVIATION Vernier Fuly CW RANGE 8 16 MHz FREQUENCY TUNE p i i i po po por 8 MHz OUTPUT LEVEL Switches
634. y Fo 3MHz R lt gt L CA 20 dB ed E me 27 dBm OS ATTENUATOR R L 4 X gt Q LPF IF 20 dBm a F2 7 dBm MODEL 86408 20 dB Bap 1 5 MHz OPTION 004 aux ar output AMPLIFIER ATTENUATOR LPF UNDER TEST REAR PANEL INPUT 2048 10 dB AMPLIFIER STEP ATTENUATOR output MIXER INPUT R L ister 4 IRF ATTENUATOR x F2 10 dBm STEP 2 POWER METER P NSOR POWER SENSO d 4 MHz F F2 3 MHz LPF REFERENCE SIGNAL Aux RF OUTPUT GENERATOR CALIBRATED STEP 20 dB AMPLIFIER ATTENUATOR OUTPUT INPUT OUTPUT mie aeons OSCILLOSCOPE n TRACKING GENERATOR VERT INPUT 6 OUTPUT F4 3 MHz 0 dBm NOI SE FILTER Se DIGITAL VOLTMETER INPUT OOF OFF 99 5 e vert INPUT mph SPECTRUM ANALYZER Q DOUBLE SHIELDED CABLE Figure 4 11 Output Level Accuracy Test Setup Complete 4 41 Performance Tests PERFORMANCE TESTS 4 26 OUTPUT LEVEL ACCURACY TEST Complete Cont d PROCEDURE Model 8640B Option 004 l Connect power meter and power sensor to the test Signal Generator s RF OUT jack Set test generator s controls as follows Meter Function COUNTER MODE EXPAND LOCK Source AM FM RANGE FREQUENCY TUNE OUTPUT LEVEL Switches OUTPUT LEVEL Vernier ON OFF LEVEL off off INT OFF OFF 256 512 MHz 512 MHz 15 dBm CAL O
635. y counter is used to measure drift as temperature is changed A temperature controlled chamber is used to vary the temperature See able 4 1 Recommended Test Abridgements TEMPERATURE CONTROLLED CHAMBER MODEL 86408 OPTION 004 INPUT 500 AUX RF OUTPUT REAR PANEL Figure 4 2 Frequency Stability vs Temperature Test Setup EQUIPMENT Frequency Counter HP 5327C Temperature Controlled Chamber Statham Model 325 PROCEDURE 1 Connect equipment as shown ip Figure 4 2 after setting Signal Generator s controls as follows COUNTER MODE EXPAND Off LOCK Source FM io owe dE ve Oe o9 o ORF RANGE 32 64 MHz FREQUENCY TUNE 50 MHz RF ON OFF LON 2 Set temperature controlled chamger for 15 C Allow Signal Generator to stabilize for two hours Then note frequency counter reading 3 Set chamber for 35 C Again allow Signal Generator to stabilize for two hours Frequency change from reading noted in step 2 should be less than 50 kHz 50 kHz 4 18 Model 8640B Option 004 Performance Tests PERFORMANCE TESTS 4 17 FREQUENCY STABILITY VS LINE VOLTAGE TEST SPECIFICATION Stability vs Line Voltage 5 to 10 line voltage change 1 ppm normal mode NOTE Stability specifications for phase lock mode are deter
636. z and 10 dBm but applies to all bands Supplemental information only 1 42 Pulse Modulation 1 43 Also included on the AM function switch is a position for external PULSE modulation In this mode pulse inputs with repetition rates to 500 kHz and widths down to 2 uscan be applied to modulate the RF carrier Rise and fall times vary with output frequency down to 1 usfrom 8 to 512 MHz 1 44 Pulse inputs turn the RF on Hence with no pulse inputs the RF will read approximately zero on the built in level meter For pulse inputs greater than 0 5V the RF output is on calibration is preserved and the level meter reads the pulse on power of the RF output For repetition rates below that specified the pulsed RF output is still available but the pulse on level is no longer calibrated or metered 1 45 Frequency Modulation 1 46 FM is calibrated metered and constant with RF frequency and band changes Peak deviations to at least 0 57 of carrier frequency are available i e 196 of the minimum frequency in each octave band On the 256 512 MHz band for example Model 8640B Option 004 0 5V div Figure 1 5 Pulsed RF 20 MHz Carrier Frequency at400 kHz Pulse Rate and 1 us Pulse Width the maximum deviation is 2 56 MHz peak or 5 12 MHz peak to peak With this wide deviation capability it is possible to sweep the generator using the dc coupled FM mode and a sawtooth input to test and align IF filters and discrimina

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