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Service Manual 1502B Metallic Time

1. 011 0123 00 B BNC Connector female to female 103 0028 00 E Slide Rule Calculator 003 0700 00 m Slide Application Note bound in this manual 062 8344 m Accessory Pouch 016 0814 00 E Operator Manual Sora es 070 6266 1502 MTDR Service Manual Options and Accessories Optional Accessories 1502B MTDR Service Manual Service 070 6267 Battery Pack 016 0813 00 Chart Recorder 15 119 3616 00 Chart Paper single roll 006 7647 00 Chart Paper 25 roll Pack wasis 006 7677 00 Chart Paper 100 roll pack 212 adest oa EUR RC EET sg a 006 7681 00 Connector BNC male to BNC male 103 0029 00 Connector BNC female to Alligator Clip S N gt B025708 013 0261 00 Connector BNC female to Hook tip Leads 013 0076 01 Connector BNC female to Dual Banana Plug 103 0090 00 Connector BNC male to Dual Binding Post 103 0035 00 Connector BNC male to female 103 0058 00 Connector BNC female to N male 103 0045 00 Connector BNC female to male 103 0015 00 Connector BNC female to female 103 0032 00 Connector
2. LCD Drive To LCD Drivers Voltage pues Circuitry EL EL To EL Backlight Switching Power m Circuitry Supply 50 Pin Connector 1502B MTDR Service Manual Circuit Descriptions Rotary Binary Switches Switch Multiplexers Resistive Shaft Encoders Analog to Digital Converter 1502B MTDR Service Manual These switches control MENU VIEW INPUT VIEW STORE VIEW DIFF STORE The rotary binary switches provide a 4 bit binary value indicating their position The outputs are tied to the inputs of the multiplexers The position of the rotary switches control the following functions FILTERING SET REF SET DELTA HORIZONTAL GAIN DIST DIV Vp COARSE Vp FINE The switch multiplexers are U2024 U2025 U3025 and U3031 These dual four channel multiplexers multiplex the switch settings of the push button and rotary switches onto the data bus The control signal MUXCS in conjunction with selects the multiplexers while Ag and A determine which switch bank is placed on the data bus The resistive shaft encoders R1022 R2024 and R3020 are dual concentric 360 rotation potentiometers with the wipers set 180 out of phase with respect to each other The wipers are tied to the analog to digital converter inputs of ADC U2023 The three resistive shaft encoders control the following functions B VERTICAL GAIN B VERTICAL POSITION m HORIZONTAL POSITION Cursor The ADC U202
3. Characteristic Performance Requirement Supplemental Information Excitation Pulse Reflected Pulse lt 200 ps 0 096 feet Vp set to 0 99 10 to 90 into a precision short Aberrations 5 peak within 0 to 10 feet after rise Excluding front panel aberrations 0 5 peak beyond 10 feet itter lt 0 02 feet lt 40 ps p p Horz scale 0 1 ft div Vp set to 0 99 DIST DIV set to 0 1 ft div lt 0 2 feet lt 400 ps Horz scale 1 ft div At 23 4 feet to 46 8 feet jitter is lt 0 04 feet Output Impedance 500 2 After risetime stabilizes into 50Q termination Pulse Amplitude 300 mV nominal into 50Q load Pulse Width 25 us nominal Pulse Repetition Time 200 us nominal Vertical Scales 0 5 mp div to 500 mpj div 240 values includes 1 2 5 sequences Accuracy Within 3 of full scale Set Set incident pulse within 3 Combined with VERT SCALE control Vertical Position Any waveform point is moveable to center screen Displayed Noise 5 or less filter set to 1 2 peak or less filter set to 8 Distance Cursor Resolution 1 25th of 1 major division Cursor Readout Range 2 ftto gt 2 000 ft Resolution 0 004 ft Distance Measurement For cables with Vp 0 66 Accuracy 1 6 inches or 1 of distance measured For delta mode measurements whichever is greater Error lt 0 5 for distance gt 27 ft Error lt 1 0 for distance gt 14 ft Error lt 2 096 for distance gt 7 ft Error lt 1096 for
4. Figure 6 48 Waveform Display You might have to adjust R1018 Contrast Adjust on the Front Panel Board to get a clear display see LCD Check and Adjustments in this section 1 Turn the POWER 2 Remove the AC plug from the rear panel of the instrument 1502B MTDR Service Manual Calibration 3 Connect an external 12 VDC power supply into the battery port Jacks Make sure you observe proper polarity The positive side of the battery pack port is next to the Power Supply Board The negative side is next to the Driver Sampler Board 4 Adjust the external 12 VDC supply for 11 5 VDC output at the terminals of the battery input 5 Connect a DC ammeter in series with the positive side of the 12 VDC supply The current measurement must not exceed 350 mA Power Supply Board Figure 6 49 Battery Pack Port Jacks on Frame The following test points are located on the Power Supply Board N U2010 KH CR2015 H N O TP2010 E CR2012 CR2012 Figure 6 50 CR2012 on Power Supply Board 1502B MTDR Service Manual 6 31 Calibration 6 32 6 Connect the positive probe of the voltmeter to the front side CR2012 the Power Supply Board th
5. Figure 6 24 Noise Diagnostic Display NOTE If the instrument does not meet this specification refer to the Circuit Descriptions chapter and the Troubleshooting section of the Maintenance chapter of this manual 11 Press MENU once to return to the Service Diagnostic Menu Do not exit from the Service Diagnostic Menu because you will use it in the next check Sampling Efficiency Check If the instrument fails this check the waveforms might not look normal If the efficiency is more than 10046 the waveforms will appear noisy If the efficiency is below the lower limit the waveform will take longer more pixels to move from the bottom to the top of the reflected pulse This smoothing effect might completely hide some events that would normally only be one or two pixels wide on the display 1l While in the Service Diagnostic Menu select the Sampling Efficiency Diagnostic and follow the directions shown on the display Exit Service Diagnostic Menu Sampling Efficiency Diagnostic Noise Diagnostic Impedance Diagnostic Offset G ain Diagnostic RAM ROM Diagnostics Timebase is Normal Auto Correction Move 2 to select then push MENU button Figure 6 25 Service Diagnostic Menu 1502B MTDR Service Manual 6 15 Calibration Offset Gain Check RAM ROM Check 6 16 2 Press MENU once to return to the Service Diagnostic Menu Do not exit from the Service Diagnostic Menu because you will us
6. PHASE DETECTOR ASSY 671 1594 90 REV Dat es Assembly Assembly Diagram part number reference number number Figure 9 1 Special Schematic Symbols 1502B MTDR Service Manual 9 3 Diagrams A1 MAIN CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD BT1010 C7030 C7040 C1010 C7041 C1011 C7042 C1020 C7043 C1021 C8010 C1022 C1023 C8020 C8021 C1024 C8022 C1030 C8023 C1031 C8024 C1032 C8040 C1040 C1041 C9010 C9011 C1042 C9020 C1043 C9021 C2010 C9022 C2011 C9023 C2012 C2013 C9024 C9025 C2014 C9030 C2015 C9031 C2016 C9032 C2020 C9033 C2021 C2030 C9034 C9035 C2031 C2032 CR1020 C2033 CR1021 C2034 CR1022 C2035 CR1023 C2036 CR3031 CR4030 C2037 C2038 CR4031 C2039 CR4032 C2040 CR5030 C2041 CR5040 C2042 CR8020 CR9010 C2043 C2044 J2010 C2045 J5040 T C2046 J6010 T Back Side Components 9 4 1502B MTDR Service Manual Diagrams A1 NAIN CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD J9010 L5030 L5040 Q1010 Q1020 Q1021 Q1030 Q1031 Q2011 Q2012 Q3030 Q4030 Q4031 Q4040 Q5020A Q5020B Q5030 Q5031 Q5032A Q5032B Q6020 Q7020 Q7021 Q7030 Q8020 Q9010 Q9020A Q9020B Q9021 R1010 R1011 R1012 R1013 R1014 R1015 R1016 R1020 R1021 R1022 R1023 T Back Side Compon
7. The instrument should remain shut down 9 Turn the 1502B POWER off Main Board 12 VDC Check and Adjust Figure 6 46 Location of Main Board in Instrument 12 VDC Test points in this check are located on the Main Board 1 Turn the instrument over to access the Main Board 2 Attach the positive probe from the voltmeter to the side facing the edge of the board of C9031 3 Attach the negative probe to the other side of C9035 4 Turn instrument POWER on and check that less than 4 Watts is drawn from the Variac 5 Adjust R9032 for 12 0 VDC 1502B MTDR Service Manual 6 29 Calibration 6 30 12 VDC DC Power Check JOcOZ7u L TEOLLA 4J O ud 0 TOSH 4 4 9 4 ZO6Y ZO6D Figure 6 47 Main Board Probe Points Test points in this check are located on the Main Board 1 Move the positive probe to the ground side of C9035 the side away from the edge of the board 2 Verify that the voltage is 11 8 to 12 2 VDC 3 Verify that the LCD shows the following display a
8. SUPPLY ASSEMBLY 80009 620 0477 03 9 6 15028 MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont Serial No Serial No Mfr Effective Discontd Qty Name amp Description Code Assy Tektronix Number Part Number Mfr Part Number 1 4 5 9 670 9286 00 670 9286 01 670 9286 02 670 9286 03 670 9286 04 670 9286 05 670 9291 00 670 9291 01 670 9291 02 670 9291 03 670 9291 04 672 1241 00 118 9050 00 670 6592 00 R010100 R010141 R020399 B036427 B036454 B037400 R010100 B021135 B025716 B036454 B037400 B010100 B037543 1502B MTDR Service Manual R010140 R020398 B036426 B036453 B037399 B021134 B025715 B036453 8037399 B037542 CIRCUIT BOARD ASSEMBLIES Con t CKT BD ASSY POWER SUPPLY CKT BD ASSY POWER SUPPLY CKT BD ASSY POWER SUPPLY CKT BD ASSY POWER SUPPLY CKT BD ASSY POWER SUPPLY CKT BD ASSY POWER SUPPLY CKT BD ASSY S R DRIVER SAMPLER CKT BD ASSY S R DRIVER SAMPLER CKT BD ASSY S R DRIVER SAMPLER CKT BD ASSY S R DRIVER SAMPLER CKT BD ASSY S R DRIVER SAMPLER CKT BD ASSY DISPLAY MODULE CKT BD ASSY DISPLAY MODULE OPTION 03 ONLY CKT BD ASSY POWER FUSE JACK 80009 80009 80009 80009 80009 80009 80009 80009 80009 80009 80009 80009 670 9286 00 670 9286 01 670 9286 05 670 9286 03 670 9286 04 670 9286 05 670 9291 00 670 9291 01 670 9291 02 670 9291 03 670 9291 04 672 1241 00 118 9050 00 670 6592 00
9. Cursor on Rising Edge at First Horizontal Graticule Cursor on Rising Edge at Last Horizontal Graticule Rising Edge at Center of Display Rising Edge with Scale at 1 0 mp div 5 37 5 39 6 2 6 2 6 3 6 4 6 5 6 5 6 6 6 6 6 8 6 8 6 9 6 9 6 9 6 10 6 11 6 11 6 11 6 12 6 13 6 13 6 14 6 14 6 15 6 15 6 16 6 17 6 18 6 18 6 19 6 19 6 20 6 20 6 21 6 22 6 22 Contents vi Figure 6 37 Figure 6 38 Figure 6 39 Figure 6 40 Figure 6 41 Figure 6 42 Figure 6 43 Figure 6 44 Figure 6 45 Figure 6 46 Figure 6 47 Figure 6 48 Figure 6 49 Figure 6 50 Figure 6 51 Figure 6 52 Figure 6 53 Figure 6 54 Figure 6 55 Figure 6 56 Figure 6 57 Figure 6 58 Figure 6 59 Figure 6 60 Figure 6 61 Figure 6 62 Figure 6 63 Figure 6 64 Figure 7 1 Figure 7 2 Figure 7 3 Figure 7 4 Figure 7 5 Figure 7 6 Figure 7 7 Figure 7 8 Rising Edge with Max Hold on 6 22 Head Alignment Chart Print 6 23 Circuit Board Locations in the Instrument 6 24 Power Supply sxc caus 6 26 Power Supply Test Points TP1020 and TPIOIO 6 26 Power Supply Test Point TP2030 6 27 Connector Plug P5040 and Pins 75040 on Bottom of 6 28 Power Supply Test Point TP1020 6 28 Power Supply Test Point 2030 6 29
10. 0 6 V 15V R a t t 12V Adjustable egu ato On board source Front supply Hybrid panel Step tri connector 25 us Step lt gt s One Shot Generator Sample trigger pu Bridge P bias B 5 us sampler Sampling strobe bridge One Shot generator J B Inverted Video Out 5 2 Sampler Figure 5 12 Driver Sampler Block Diagram Bridge Bias bridge bias for the first sampler is set by 01070 With a zero voltage input signal the circuit holds 2 0 V on the bridge inputs As the input signal moves the 4 V window also moves to stay centered around it This centering is accomplished by feeding part of the output of U2050A into the bridge bias circuit The outputs of the bridge bias circuit are available on TP1020 and TP1021 Trigger Pulse Shapers There a re two incoming triggers the sample and the step Both require modification before they are usable by the hybrid The sample trigger is a 30 to 50 ns negative TTL signal This pulse is buffered by Q2030 then coupled to the hybrid through T1020 This provides a differential drive that can have common mode voltage on it The sampler pulse is also stretched to 5 Us by U3030B to strobe the second sampler The step trigger GEN TRIG is 3 to 5 Us negative TTL signal stretched to the proper 25 Us pulse length by U3030A CR3020 and CR3021 provide a logic OR of the incoming signal and the output of the one shot This prevents the introduction
11. ASSY SP ELEC 14 26 AWG 6 125L 80009 174 0953 00 FROM 1030 TO 1 1 5040 W6010 174 0951 00 CA ASSY SP ELEC 20 28 AWG 300V RMS 80009 174 0951 00 FROM DISPLAY MODULE 5 AND A2A1J 1020 TO 1 1 6010 W9010 174 0952 00 CA ASSY SP ELEC 20 28 AWG 6 125 RIBBON 80009 174 0952 00 FROM 4 3040 A1A1J 9010 J101 174 0957 00 B010100 B037303 CA ASSY PWR 2 STRAND W CONN 80009 174 0957 00 FROM A3T210 TO POWER SUPPLY 198 5460 00 R010100 R020421 WIRE SET ELEC POWER SUPPLY MODULE 80009 198 5460 00 198 5460 01 R020422 WIRE SET ELEC POWER SUPPLY MODULE 80009 198 5460 01 9 36 15028 MTDR Service Manual Diagrams General Information Assembly Numbers Grid Coordinates Electrical Parts Locator Schematic Symbols Component Values 1502B MTDR Service Manual Each assembly in the Instrument is assigned an assembly number e g A1 The assembly number appears in the title block of the schematic diagram in the title for the circuit board component location illustration and in the lookup table for the schematic diagram component locator The replacable parts list is arranged by assemblies in numerical sequence the components are listed by component number The schematic diagram and circuit board component location illistration have grids A lookup table with the grid coordinates is provided for to help you locate the component The component locator lookup table provides an alphanumeric listing of all cirucit numbers
12. Assy Number A3M 1 1010 1 1030 1 2010 A3A1L1010 A3A1L2020 A3A1Q1010 A3A1Q1011 A3A1Q1012 A3A1Q2010 A3A1Q2011 A3A1Q2012 A3A1Q2020 A3A1Q2021 A3A1Q2022 A3A1Q2030 A3A1Q2031 A3A1R1010 A3A1R1011 A3A1R1012 A3A1R1013 A3A1R1014 A3A1R1015 A3A1R1016 A3A1R1017 A3A1R1018 A3A1R1020 Tektronix Part Number 670 9286 131 4177 00 131 3445 00 131 1857 00 108 1230 00 108 1230 00 151 1176 00 151 1176 00 151 0736 00 151 0736 00 151 1176 00 151 1176 00 151 0188 00 151 0424 00 151 1136 00 151 1063 00 151 1063 00 308 0839 00 322 3193 00 322 3222 00 322 3309 00 322 3243 00 322 3231 00 321 0301 00 322 3303 00 322 3243 00 322 3318 00 321 0133 00 322 3189 00 Serial No Effective R010100 R010141 R010100 R020399 1502B MTDR Service Manual Serial No Discontd Qty Name amp Description R010140 R020398 CIRCUIT BD ASSY POWER SUPPLY Con t CONN HDR PCB MALE STR 1 X 31 0 15 CTR CONN HDR PCB MALE RTANG 2 X 7 0 1 CONN HDR PCB MALE STR 1 X 36 0 1 CTR COIL RF FIXED 100UH 5 POT CORE COIL RF FIXED 100UH 5 POT CORE XSTR PWR MOS P CH 100V 1 0A 0 6 OHM XSTR PWR MOS P CH 100V 1 0A 0 6 OHM XSTR NPN SI TO 92 2N4401 XSTR NPN SI TO 92 2N4401 XSTR PWR MOS P CH 100V 1 0A 0 6 OHM XSTR PWR MOS P CH 100V 1 0A 0 6 OHM XSTR SIG BIPOLAR PNP 40V 200MA 250MHZ AMP XSTR NPN SI TO 92 MPS2369A XSTR PWR MOS N CH 100V 14A 0 16 OHM XSTR PWR MOS N CH 60V 0 8A 0 8 OHM XST
13. 1 Adjust the gt POSITION control to obtain 100 000 ft in the distance window ANM MM ME ee LL F Figure 2 8 Waveform with Gain at 5 00 mp div 2 Using the POSITION control and VERT SCALE control set the gain to 5 00 mp div Keep the waveform centered vertically in the display Press MENU Using the POSITION control select Diagnostics Menu Press MENU again Using the POSITION control select Service Diagnostic Menu Press MENU again Using the POSITION control select Noise Diagnostics Press MENU again and follow the instructions on the display 2 5 Operator Performance Checks 10 Exit from Noise Diagnostics but do not exit from the Service Diagnostic Menu yet 4 Offset Gain Check If the instrument fails this check it should not be used for loss or impedance measurements Send it to be serviced when possible 1 Inthe Service Diagnostic Menu select the Offset Gain Diagnostic and follow the directions on the display NOTE Occasionally the instrument might not pass the 48 dB step This is no cause for alarm If the remainder of the steps do not fail proceed as normal Refer to Chapter 6 of this manual There are three screens of data presented in this diagnostic The Pass Fail level is 3 for any single gain setting tested 2 Exit from Offset Gain Diagnostic but do not leave the Service Diagnostic Menu yet 5 Sampling Efficiency If the i
14. 31433 31433 1W 344 31433 31433 0 985 31433 31433 31433 04222 04222 31433 31433 31433 31433 31433 31433 31433 31433 31433 31433 31433 18796 04222 04222 31433 04222 31433 24165 18796 31433 31433 Mfr Part Number C114C224M5Y5CA C114C224M5Y5CA KMC25T101M8X11LL C114C224M5Y5CA C114C224M5Y5CA CEUST1E100 C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA SR595C104MAAAP 1 SR155C103KAA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA DD09B10 Y5F 102K 200V SR305C105MAATRSTDII SR305C105MAATRSTDII 114 224 5 SR155C103KAA C114C224M5Y5CA 923CX7R104M050B DD09B10 Y5F 102K 200V C114C224M5Y5CA C114C224M5Y5CA 8 9 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1C3022 A1A1C3023 A1A1C3030 A1A1C3040 A1A1C3041 A1A1C3042 A1A1C3043 A1A1C3044 A1A1C3045 1 1 3046 A1A1C3047 A1A1C3048 A1A1C4020 A1A1C4021 A1A1C4022 A1A1C4030 A1A1C4040 A1A1C4041 A1A1C5010 A1A1C5020 A1A1C5021 A1A1C5022 A1A1C5023 A1A1C5024 A1A1C5025 A1A1C5030 A1A1C5031 A1A1C5032 A1A1C5033 A1A1C5040 A1A1C5041 A1A1C5042 6 10 Serial No Serial No Effective Tektronix Part Number 670 9285 XX 281 0925 01 281 0925 01 283 0181 00 283 0107 00 283 0167 00 283 0108 00 283 0330 00 283 0359 01 281 0925 01 281 0925 01 283 0
15. 6 35 Zero Offset 6 38 After Adjustments are Completed 6 40 vous a 98 EIS opa asus Ga 7 1 licei 7 1 Preventive Maintenance ee whoa mae ke 7 1 Part Removal and Replacement 7 2 Troubleshooting 7 14 Control Panel Installation 7 20 and Bottom EMI Shield Installation 7 21 Installing the Case Cover Over Chassis 7 22 Replaceable Electrical Parts 8 1 Iran 9 1 Replaceable Mechanical Parts 10 1 1502 MTDR Service Manual Contents List of Figures 1502B MTDR Service Manual Figure 1 1 Figure 1 2 Figure 1 3 Figure 1 4 Figure 1 5 Figure 1 6 Figure 1 7 Figure 1 8 Figure 1 9 Figure 1 10 Figure 1 11 Figure 1 12 Figure 1 13 Figure 1 14 Figure 1 15 Figure 1 16 Figure 1 17 Figure 1 18 Figure 1 19 Figure 1 20 Figure 1 21 Figure 1 22 Figure 1 23 Figure 1 24 Figure 1 25 Figure 1 26 Figure 1 27 Figure 1 28 Figure 1 29 Figure 1 30 Figure 1 31 Figure 1 32 Figure 1 33 Rear Panel Voltage Selector Fuse AC Receptacle D
16. Circuit Descriptions 1502B MTDR Service Manual to C8021 through R8025 to generate an exponentially rising pulse of about 4 VDC peak during the pulse width Dual transistor 08020 15 a differential amplifier that is used as a voltage comparator to detect when the pulse on C8021 has reached the DC voltage level set through U4021B and 8023 by the zero distance calibration circuit This DC voltage level from zero to 4 VDC allows setting the time when the voltage comparator switches a range of about 20 ns Dual transistor Q9020 is connected as a current source providing a constant 2 mA bias to the emitters of Q8020 Between pulses this current flows through Q8020B When the exponential pulse reaches the adjustable voltage level the current is rapidly transferred to Q8020A causing a negative going pulse at R8020 This pulse is coupled to the output stage Q9010 through C9020 and R9020 Transistor Q9010 is biased to 0 5 mA between pulses to obtain fast turn on and provides a positive going 5 VDC pulse to U8010B and U8010C Flip flop U7010A is set or reset by the processor to steer the pulse either to the option port or the driver The negative going pulse from gate U8010B or U8010C is logically OR d by U8010A then applied to C9010 and R9010 This pulse is fed back to the input of the gates U8010B and U8010C through CR9010 to obtain a one shot action which stretches the driver strobe pulse width to 5 Us The driver strobe is made availabl
17. Rear Panel S lt 6 _ 9 Figure 7 3 Power Supply Module Rear Panel 2 Remove the screw and washer located below the power switch on the instrument side panel Figure 7 3 7 3 Remove the screw and washer holding the power supply module to the bottom chassis Figure 7 3 4 1502B MTDR Service Manual 7 5 Maintenance Removing the Power Supply Board Removing the Power Transformer Removing the Power Cord 7 6 Receptacle 4 Remove two screws holding the power supply module to the rear chassis panel One is located near the AC power receptacle and the other is directly above the fuse holder Figure 7 3 6 Remove the power supply module from the instrument by moving it toward the front of the instrument guiding the power switch away from the mechanical linkage assembly NOTE The screws identified as 1 hold the circuit board to the module They should not be removed until you are ready to remove this circuit board from the module next procedure e Remove power supply module per previous procedure Remove the two conductor harmonica connector Figure 7 3 3 Remove the four conductor harmonica connector Figure 7 3 2 Remove four screws holding the circuit board to the module Figure 7 3 1 Remove the Power Supply Board by carefully lifting up Be sure the large capacitor on the bottom of the board clears the two nut blo
18. 31 Turn the VERT SCALE control clockwise until the leading edge of the incident pulse is five major divisions high about 200 mp Position the waveform so that it is centered horizontally and vertically on the middle graticule lines 2 5 divisions below the center horizontal graticule line and 2 5 divisions above MM s lt c o o ofo 4 o o o e off gt 4 4 Figure 6 32 Incident Pulse Centered Vertical Increased 5 6 Turn NOISE FILTER control to HORZ SET REF Using the lt gt POSITION control set the cursor to the point where the lower portion of the pulse s rising edge first crosses a major horizontal graticule line should be about half a division from the bottom of the pulse Press STORE Turn the NOISE FILTER to 1 avg _ 0 000 ft A Figure 6 33 Cursor on Rising Edge at First Horizontal Graticule 9 Using the lt gt POSITION control set the cursor to the point where the upper portion of the pulse s rising edge crosses a major horizontal graticule line should be about half a division from the top of the pulse 1502B MTDR Service Manual Calibration Jitter Check 1502B MTDR Service Manual 10 Verify that the distance is less than or equal to 0 096 ft A 00761 A TTO Figure
19. S2010 Figure 6 53 R2012 on Power Supply Board 4 Connect the posttive probe to the side nearest the front panel and the negative probe to the other end The voltage drop across R2012 should be between 0 4 VDC and 1 2 VDC 5 Turn the POWER on The voltage reading across R2012 should change only slightly 10 mV NOTE The charging current will vary according to the level of charge already on the battery With a fully charged battery the voltage across R2012 should be approximately 0 4 VDC With a battery below 11 Volts R2012 should read approximately 1 2 VDC 1502B MTDR Service Manual 6 33 Calibration Impedance Check If the instrument fails this check it should not be used for loss or impedance measurements The following test points are located on the Driver Sampler Board Driver Sampler Board 24 S Figure 6 54 Driver Sampler Board Location 1 Turn off the POWER to the instrument 2 Remove the cover of the Driver Sampler Board see Maintenance chapter q i a U1010 x y 4 CU 8302 J C2026 3 3020 O C2031 C 7 BEE MEN Figure 6 55 TP1030 on Driver Sampler Board 6 34 1502B MTDR Service Manual Calibration 3 Using a precision Ohmmeter measure the resistance from the 0 6 VDC supply TP1030 to the center conductor
20. 00 322 3331 00 322 3164 00 322 3001 00 322 3001 00 322 3068 00 322 3280 00 322 3222 00 322 3097 00 322 3068 00 322 3184 00 322 3250 00 322 3068 00 Effective B021152 1502B MTDR Service Manual Discontd Qty Name amp Description CIRCUIT BD ASSY MAIN W O EPROM Con t RES FXD FILM 200 OHM 1 0 2W RES FXD FILM 619 OHM 1 0 2W RES FXD METAL FILM 12 1K OHM 1 0 2W RES FXD FILM 5 11K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD FILM 40 2K OHM 1 0 2W RES FXD FILM 200 OHM 1 0 2W RES FXD FILM 23 7K OHM 1 0 2W RES FXD FILM 5 11K OHM 1 0 2W RES FXD METAL FILM 8 25K OHM 1 0 2W RES FXD FILM 243 OHM 1 0 2W RES FXD FILM 249 OHM 1 0 2W RES FXD FILM 255 OHM 1 0 125W RES FXD FILM 261 OHM 1 0 2W RES FXD FILM 267 OHM 1 0 2W RES FXD METAL FILM 274 OHM 196 0 2W RES FXD FILM 287 OHM 1 0 2W RES FXD METAL FILM 10 OHM 1 0 2W RES FXD FILM 127K OHM 1 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W RES FXD FILM 31 6K OHM 1 0 2W RES FXD FILM 499 OHM 1 0 2W RES FXD METAL FILM 10 OHM 1 0 2W RES FXD METAL FILM 10 OHM 1 0 2W RES FXD METAL FILM 49 9 OHM 0 196 0 2W RES FXD FILM 8 06K OHM 1 0 2W RES FXD METAL FILM 2 00K OHM 1 0 2W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD METAL FILM 49 9 OHM 0 196 0 2W RES FXD FILM 806 OHM 1 0 2W RES FXD METAL FILM 3 92K OHM 1 0 2W RES FXD METAL FILM 49 9 OHM 0 196 0 2W Mfr Code 91637 91637 57668 91637 57668 91637 91637 57668 91637 57668 57668 57668 197
21. 1 Horizontal Scale If the instrument fails this check it must be repaired before any distance Timebase Check measurements can be made with it 1 Turn 1502B power The display should look very similar to Figure ae jo 00008 Figure 2 1 Start up Measurement Display 2 Connect the 3 foot precision cable to the front panel CABLE connector The display should now look like Figure B 2 a o Lo 0 0008 _ Figure 2 2 Measurement Display with 3 foot Cable 3 Using the dP POSITION control measure the distance to the rising edge of the waveform at the open end of the cable The distance shown on the display distance window upper right corner of the LCD should be from 2 87 to 3 13 feet 0 875 to 0 954 m 2 2 1502 MTDR Service Manual Operator Performance Checks 1502B MTDR Service Manual P li 8 000 ft Figure 2 3 Cursor at End of 3 foot Cable 4 Remove the 3 foot cable and connect the 50Q terminator 5 Change the DIST DIV to 200 ft div 50 m div 6 Turn the q gt POSITION control clockwise until the distance window shows distance greater than 2 000 feet gt 600 m The waveform should be a flat line from the pulse to this point ee b 0 Figure 2 4 Flat Line Display Out to 50 000 Feet 7 Turn the POSITION control counterclockwise until the distance window shows a distance
22. 20 hours maximum Limited to 10 days continuous charge Battery will charge whenever instrument is plugged in Battery can be removed during AC operation Operation terminates prior to cell reversal 2 Amp hours typical Bat low will be indicated on LCD when capacity reaches approximately 10 1502B MTDR Service Manual Specifications Environmental Characteristics Characteristic Performance Requirement Supplemental Information Temperature Operating 10 C to 55 C Battery capacity reduced at other than 15 C to 25 C Non operating 62 C to 405 With battery pack removed Storage temp with battery pack in is 20 C to 55 C Contents on non volatile memory stored waveform might be lost attemps below 40 C Humidity to 100 Internal desiccant Altitude MIL T 28800C Class 3 Operating to 15 000 ft Non operating to 40 000 ft Vibration 5 to 15 Hz 0 06 inch p p MIL T 28800C Class 3 15 to 25 Hz 0 04 inch p p 25 to 55 Hz 0 013 inch Shock Mechanical Pulse 30 g 11 ms 1 2 sine wave total of 18 shocks MIL T 28800C Class 3 Bench Handling MIL STD 810 Method 516 Procedure V Operating 4 drops each face at 4 inches or 45 degrees Cabinet on front cover off with opposite edge as pivot Non operating 4 drops each face at 4 inches or 45 degrees Cabinet off front cover off with opposite edge as pivot Satisfactory opera tion after drops inch double amplitude orbital path at 5 Hz 6 MIL ST
23. 2009 00 156 3180 00 156 2463 00 156 2415 00 156 3110 00 136 0755 00 156 2583 00 156 2583 00 156 2009 00 156 2583 00 156 2763 00 156 2583 00 156 2763 00 156 2767 00 119 2736 00 156 2096 00 156 2759 00 156 2092 00 156 2096 00 156 2098 00 156 2437 00 156 2768 00 156 2759 00 Discontd Qty Name amp Description CIRCUIT BD ASSY MAIN W O EPROM Con t IC MEMORY CMOS SRAM 8K X 8 200N5 200NA IC MEMORY CMOS SRAM 8K X 8 200N5 200NA DIGITAL HCMOS DEMUX DECODER IC DGTL CPU 6MHZ Z 80 DIP 40 DIGITAL CMOS GATES 8 INPUT IC DIGITAL HCMOS GATE HEX INV SCHMITT TRIG IC DIGITAL CMOS BUFFER DRIVER OCTAL INV IC LINEAR VOLTAGE REGULATOR DIGITAL HCMOS GATE DUAL 4 INPUT DIGITAL HCMOS FLIP FLOP DUAL D TYP IC DIGITAL HCMOS GATE TRIPLE 3 INPUT NOR IC DITIAL HCMOS GATE QUAD 2 INPUT OR IC DIGITAL HCMOS TRANSCEIVER OCTAL NONINV IC DIGITAL HCMOS BUFFER NONINV OCTAL SOCKET DIP PCB 28 POS 2 X 14 0 1 X 0 6 CTR IC DIGITAL HCMOS DEMUX DECODER IC DIGITAL HCMOS DEMUX DECODER IC DIGITAL HCMOS FLIP FLOP DUAL D TYP IC DIGITAL HCMOS DEMUX DECODER IC DIGITAL HCMOS FLIP FLOP DUAL J K DIGITAL HCMOS DEMUX DECODER DIGITAL HCMOS FLIP FLOP DUAL J K IC DGTL CHMOS COUNTER TIMER 82C54 CRYSTAL SCOPE IC DIGITAL ALSTTL FLIP FLOP QUAD D TYPE DIGITAL ALSTTL FLIP FLOP DUAL J K IC DIGITAL ALSTTL GATE QUAD 2 INPUT NOR IC DIGITAL ALSTTL FLIP FLOP QUAD D TYPE IC DIGITAL ALSTTL
24. 4 5 6 mu M 7 02 07 POWER 8 08 PULL ON 9 SET REF 9 100209 Figure 1 3 1502B Front Panel Controls 1502B MTDR Service Manual Operating Instructions Display View Difference Front Panel Controls NOISE FILTER gt HORZ nd SET REF 1502B MTDR Service Manual CAUTION Do not connect live circuits to the CABLE connector Voltages exceeding 5 volts can damage the driver or sampler circuits Bleed the test cable of any residual static charge before attaching it to the instrument To bleed the cable connect the standard 500 terminator and standard female to female BNC connector together then temporarily attach both to the cable Remove the connectors before attaching the cable to the instrument When testing receiving antenna cables avoid close proximity to transmitters Voltages may appear on the cable if a nearby transmitter is in use resulting in damage to the instrument Before testing be sure that there are no RF voltages present or disconnect the cable at both ends Power Front Panel to Cursor Type Waveform Cursor Distance Window ac 0 000 ft View Input d Indicator View Store__ Indicator Indicator Store Indicator 1 avg 500 0 2 ft Selected Selected Selected Noise Filter Vertical Scale Distance per Division Figure 1 4 Display and Indicators 1 CABLE A female BNC connector for attaching a cable to
25. 8 7 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A1 A1 A1 A1U2020 1 1010 1 1010 1 1 A1A1BT1010 A1A1C1010 1 1 1011 A1A1C1020 A1A1C1021 A1A1C1022 A1A1C1023 A1A1C1024 A1A1C1030 A1A1C1031 A1A1C1032 8 8 Tektronix Part Number 672 1253 672 1312 160 4412 02 160 4412 03 160 4412 06 160 4412 07 160 4412 08 160 4412 09 146 0049 00 146 0079 00 670 9285 146 0049 00 281 0925 01 281 0925 01 281 0925 01 281 0925 01 283 0359 01 283 0359 01 283 0359 01 283 0190 00 281 0925 01 283 0359 01 Serial No Effective R010100 R010157 R010185 R 020399 B021135 B035825 B021135 B025000 R010100 Serial No Discontd Qty Name amp Description BD ASSY MAIN BD W EPROM amp BATT R010156 R010184 R020398 B021134 B035824 B021134 STANDARD INSTR CKT BD ASSY MAIN W EPROM amp BATTERY MOD NB ONLY CKT BD ASSY MAIN W EPROM amp BATTERY IC DGTL EPROM PRGM IC DGTL EPROM PRGM IC DGTL EPROM PRGM DGTL EPROM PRGM IC DGTL EPROM PRGM DGTL EPROM PRGM BATTERY STORAGE 3 5V 750MAH SFTY CONT BATTERY SILVER OXIDE 3 0V MOD NB ONLY CIRCUIT BD ASSY MAIN W O EPROM BATTERY STORAGE 3 5V 750MAH SFTY CONT CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 1000PF
26. A1 672 1312 00 8025000 8025368 BD ASSY MAIN W EPROM amp BATTERY 80009 672 1312 00 672 1312 01 8025369 8035824 BD ASSY MAIN W EPROM amp BATTERY 80009 672 1312 01 672 1312 02 8035825 8036694 CKT BD ASSY MAIN W EPROM amp BATTERY 80009 672 1312 02 672 1312 03 B036695 B037359 CKT BD ASSY MAIN BD W EPROM amp BATTERY 80009 672 1312 03 672 1312 04 8037360 BD ASSY MAIN W EPROM amp BATTERY 80009 672 1312 04 1 1 670 9285 00 R010100 B020616 CKT BD ASSYLMAIN W O EPROM 80009 670 9285 00 670 9285 01 8020617 8020797 CKT BD ASSYLMAIN W O EPROM 80009 670 9285 01 670 9285 00 8020798 8020816 CKT BD ASSYLMAIN W O EPROM 80009 670 9285 00 670 9285 01 8020817 B021134 CKT BD ASSYLMAIN W O EPROM 80009 670 9285 01 670 9285 02 8021135 8021151 CKT BD ASSYLMAIN W O EPROM 80009 670 9285 02 670 9285 03 B021152 B036453 CKT BD ASSYLMAIN W O EPROM 80009 670 9285 03 670 9285 04 8036454 8037399 CKT BD ASSYLMAIN W O EPROM 80009 670 9285 04 670 9285 05 B037400 CKT BD ASSYLMAIN W O EPROM 80009 670 9285 05 2 672 1251 00 R010100 B020819 CKT BD ASSY FRONT PANEL 80009 672 1251 00 672 1251 01 B020820 8036453 CKT BD ASSY FRONT PANEL 80009 672 1251 01 672 1251 02 8036454 CKT BD ASSY FRONT PANEL 80009 672 1251 02 A3 620 0477 00 R010100 R 020398 POWER SUPPLY ASSEMBLY 80009 620 0477 00 620 0477 01 R 020399 R 024999 POWER SUPPLY ASSEMBLY 80009 620 0477 01 620 0477 02 8025000 8036426 POWER SUPPLY ASSEMBLY 80009 620 0477 02 620 0477 03 8036427
27. A4CR2051 A4CR 2052 A4CR 3020 A4CR3021 Tektronix Part Number 670 9291 281 0775 00 285 0627 00 290 0782 01 290 0844 00 290 0844 00 283 5002 00 283 0359 01 283 5002 00 283 0359 01 290 0844 00 290 0844 00 281 0775 00 283 0193 00 281 0775 00 281 0775 00 290 0844 00 290 0844 00 283 5002 00 283 0359 01 283 5002 00 283 0359 01 281 0775 00 281 0775 00 152 0322 00 152 0141 02 152 0141 02 152 0322 00 152 0333 00 152 0333 00 152 0333 00 152 0322 00 152 0322 00 Effective B021135 B036427 B021135 B036427 B021135 B036427 B021135 B036427 1502B MTDR Service Manual Serial No Discontd Qty Name amp Description B036426 B036426 B036426 B036426 CKT BD ASSY S R DRIVER SAMPLER CAP FXD CER DI 0 1UF 20 50V CAP FXD PLASTIC 0 0033UF 5 100V CAP FXD ELCTLT 4 7UF 20 35VDC AL CAP FXD ELCTLT 100UF 75 20 35WVDC AL CAP FXD ELCTLT 100UF 75 20 35WVDC AL CAP FXD CER DI 1000PF 10 50V CAP FXD CER DI 1000PF 5 200V CAP FXD CER DI 1000PF 10 50V CAP FXD CER DI 1000PF 5 200V CAP FXD ELCTLT 100UF 75 20 35WVDC AL CAP FXD ELCTLT 100UF 75 20 35WVDC AL CAP FXD CER DI 0 1UF 20 50V CAP FXD CER 510 2 100 CAP FXD CER DI 0 1UF 2096 50V CAP FXD CER DI 0 1UF 2096 50V CAP FXD ELCTLT 100UF 75 20 35WVDC AL CAP FXD ELCTLT 100UF 75 20 35WVDC AL CAP FXD CER DI 1000PF 10 50V CAP FXD CER DI 1000PF 5 200V CAP FXD CER DI 1000PF 10 50V
28. Additional Features Menu Selected 1 25 Operator Performance Checks 2 1 24 4 5 3 1 Electrical Characteristics 3 1 Environmental Characteristics 3 3 Physical Characteristics e Pod a NGO d 3 4 Options and Accessories 4 1 Option 03 Battery Pack 4 Option 04 YT 1 Chart Recorder 4 Option 05 Metric Default 4 Option 07 15 Chart Recorder 4 2 Power Cord Options 4 2 PROCES SOU CS ee s as qa e A T o a E E E 4 2 Circuit Descriptions RES s 5 1 Introduction w a 5 1 5 4 PROCESSO Z arf 5 7 Option deed asa ox d ae aus 5 10 Vidco PIOCESSOE 2o iacu dad dons suds 5 13 5 15 Elapsed Time Indicator SN B020511 only 5 22 5
29. CAP FXD CER DI 100PF 5 50V SQ CAP FXD CER DI 100PF 5 50V SQ CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U Mfr Code Mfr Part Number 31433 C114C224M5Y5CA 31433 C114C224M5Y5CA 24165 5024E0200RD221K 04222 SR202A510 04222 SR211C104KAA 04222 SR152A221KAA 16546 CN15C101 31433 322C102 2G5CA 31433 C114C224M5Y5CA 31433 C114C224M5Y5CA 24165 5024E0200RD221K 31433 322 102 2 5 31433 C114C224M5Y5CA 31433 322C102 2G5CA 12954 832571 22 10 100 31433 C114C224M5Y5CA 04222 SA105E473MAA 0 985 CEUSTIE100 16546 CN15C101 31433 322C102 2G5CA 31433 322 102 2 5 31433 C114C224M5Y5CA 31433 322 102 2 5 04222 SR305E105Z7AA 04222 SR305E105ZAA 04222 SA105E473MAA 04222 SA105E473MAA 04222 SA101A510GAA 16546 CN15C101 16546 15 101 31433 C114C224M5Y5CA 31433 C114C224M5Y5CA 15028 MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1C6030 1 1 6031 A1A1C6032 A1A1C7010 A1A1C7020 A1A1C7021 A1A1C7022 A1A1C7023 A1A1C7030 A1A1C7040 A1A1C7041 A1A1C7042 A1A1C7043 A1A1C8010 A1A1C8020 A1A1C8021 A1A1C8022 A1A1C8023 A1A1C8024 A1A1C8040 A1A1C9010 A1A1C9011 A1A1C9020 A1A1C9021 A1A1C9022 A1A1C9023 A1A1C9024 A1A1C9025 A1A1C9030 A1A1C9031 A1A1C9032 A1A1C9033 Serial No Serial No Effective Tektronix Part Number 670 9285 XX 281 0925 0
30. General Information 9 1 Assembly Numbers 9 1 Comp Numbers 9 2 Comp Values 9 2 Grid Coordinates 9 1 Parts Locator 9 1 Symbols 9 1 Parts Locator Front Panel Board 9 8 Main Board 9 4 Power Fuse Jack 9 13 Power Supply 9 9 Driver Sampler Board 9 11 Schematics Driver Sampler Board 9 31 Front Panel Board Pots EL Lamp 9 27 Switches 9 26 1502B MTDR Service Manual Index Main Board Address Decode 9 16 Analog Timebase 9 23 9 24 Connectors 9 16 Digital Timebase 9 22 Miscellaneous Analog 9 20 Option Port Interface 9 19 Processor 9 17 Video Processor 9 21 Power Fuse Jack 9 32 Power Supply Board 9 29 Schematic Symbols 9 3 E Electromagnetic Spec 3 4 Features see Menu Fungus Spec 3 3 Fuse 4 2 Fuse see Power H Handling 1 1 Height Spec 3 4 Horizontal Set Reference 1 21 Humidity Spec 3 3 Indicators 1 5 Inspection xiv L Loss 1 16 M Maintenance Assembly Disassembly see Removal Replacement Equipment Required 7 1 General 7 1 Metric Default 7 13 Part Removal Replacement 7 2 AC Fuse 7 2 Battery DC Banana Plugs 7 7 Case Cover Installaation 7 22 Control Panel Watertight Seals 7 20 Desiccant Cartridee Checking 7 3 Rejuvenating 7 4 Display Module Removal 7 11 Driver Sampler Board Removal 7 11 EMI Shield Installation 7 21 Front Panel Assembly Removal 7 11 Front Pa
31. Location of Main Board in Instrument 6 29 Main Board Probe Points 6 30 Waveform on Display 6 30 Battery Pack Port Jacks on Frame 6 31 2012 Power Supply Board 6 31 Display Showing Power is Battery 6 32 Display Showing Battery Voltage is Low 6 32 R2012 on Power Supply Board 6 33 Driver Sampler Board Location 6 34 TP1030 Driver Sampler Board 6 34 R1018 on Front Panel Board 6 35 LCD Pattern with Contrast Too Light 6 35 LCD Pattern with Contrast Too Dark 6 36 LCD Pattern Adjusted for Sharpness 6 36 Waveform with Contrast Too Light 6 37 Waveform with Contrast Adjusted Correctly 6 37 Driver Sampler Board Location 6 38 Incident Pulse at 2 000 ft 6 39 1042 on Driver Sampler Board 6 39 Location Voltage Selector and Fuse Holder IE 7 2 Desiccant Cartridge on Rear of Chassis 7 4 Power Supply Module P O Rear Panel 7 5 DC Battery Banana Plugs 7 8 7 9 Elapsed Time Indicator Main Board 7 9 EPROM on Main Board 7 10 Lithium Battery on M
32. PO BOX 760 120 SAN GABRIEL DRIVE 9801 W HIGGINS SUITE 430 825 STEWART DR 515 FISHING CREEK RD 267 LOWELL ROAD RT 1 INDUSTRIAL PK PO BOX 9106 2900 SEMICONDUCTOR DR PO BOX 5928 1200 COLUMBIA AVE 11651 MONARCH ST 200 PALM BAY BLVD PO BOX 883 3065 BOWERS AVE 370 W TRIMBLE RD PO BOX 2963 31 FARINELLA DR 12920 NE 125TH WAY 927 E STATE PKY 520 E INDUSTRIAL PARK DR 2300 RIVERSIDE BLVD PO BOX 74 2096 SOUTH COLE RD SUITE 7 City State Zip Code LOS ANGELES CA 90039 1103 SANTA CLARA CA 95054 1516 SACRAMENTO CA 95834 1222 STATE COLLEGE PA 16801 2723 MINERAL WELLS TX 76067 0760 SUNNYVALE CA 94086 ROSEMONT IL 60018 4704 SUNNYVALE CA 94086 4514 NEW CUMBERLAND PA 17070 3007 HUDSON NH 03051 NORWOOD MA 02062 SANTA CLARA CA 95051 0606 GREENVILLE SC 29606 RIVERSIDE CA 92507 2114 GARDEN GROVE CA 92641 1816 MELBOURNE FL 32919 SANTA CLARA CA 95051 J OSE CA 95131 AUSTIN TX 78769 2963 EAST HANOVER 07936 KIRKLAND WA 98034 7716 SCHAUMBURG IL 60195 4526 MANCHESTER NH 03103 NORFOLK NE 68701 2242 BOISE ID 83705 1502B MTDR Service Manual Replaceable Electrical Parts Manufacturers Cross Index Cont Mfr Code Manufacturer 57668 ROHM CORP 58050 TEKA PRODUCTS INC 63312 ENDICOTT RESEARCH GROUP INC 71590 CRL COMPONENTS INC 15042 IRC ELECTRONIC COMPONENTS PHILADELPHIA DIV 75378 CTS KNIGHTS INC 15915 LITTLEFUSE INC SUB TRACOR INC 80009 TEKTRONIX INC 01073 GRAYHILL IN
33. POZ CONN HDR PCD MALE RTANG W SHRD CONN HDR PCB MALE RTANG W SHRD CONN HDR PCB MALE 2 X 10 SKT DIP FEMALE 2 X 14 Mfr Code 80009 2K262 01536 98291 53387 5Y 400 93907 86928 53718 80009 0 260 80009 01536 0 01 01536 93907 0 01 06915 0 01 83385 83385 01536 80009 18189 01536 53387 53387 53387 09922 Mfr Part Number 200 3123 00 348 0974 00 821 01655 024 051 051 0049 2520 6002UB 407 1694 00 B80 00032 003 ORD BY DESCR X 1009 129 0562 00 441 1683 00 211 0198 00 821 01655 024 ORD BY DESCR 821 01655 024 ORD BY DESCR ORD BY DESCR TCG1 2 500 03 ORD BY DESCR ORD BY DESCR ORD BY DESCR 821 01655 024 211 0198 00 1106 00 821 01655 024 2526 5002UB 2540 5002UB 2520 5002UB DILB28P 108 10 11 Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont Tektronix Part Serial No Serial No Number Number Effective Discont d FIG 10 2 78 131 4183 00 79 213 0904 00 80 441 1682 00 R010100 R020513 441 1682 01 R020514 B035824 441 1682 03 B035825 10 12 Qty Name amp Description e A FRAME AND FRONT PANEL Con t CONN HDR PCB MALE 2 X 7 SCR TPG TR 6 32 X 0 5 PNH TORX CHASSIS MAIN AL CHASSIS MAIN AL CHASSIS MAIN AL Mfr Code 53387 93907 80009 80009 80009 Mfr Part Number 2514 6002UB ORD BY DESCR 441 1682 00 441 1682 01 441 1682 03 1502B MTDR Service Manual Replaceable Mechanical Parts R
34. Timebase Introduction 1502B MTDR Service Manual 00 all Os selects 0 dB gain and word FF all 1s selects 63 75 dB gain All intervening values of 0 25 dB multiples are similarly chosen The output of the video amplifier is filtered by R2040 and C2043 for noise reduction then sent to the analog to digital converter The output may be observed at TP4040 see Figure 5 7 Figure 5 7 Video Processor Output The output of the video amplifier is converted to its digital equivalent value by ADC device U2041 The conversion is done using successive approximation technique to compare the video voltage to the 2 5 VDC reference from U3040 The device is clocked by a 1 25 MHz clock derived from the timebase oscillator and completes its 12 bit plus sign conversion in approximately 100 Us Gate U2040 provides an OR function for the ADC start conversion trigger and read pulses from the processor system Either pulse selects the ADC for control and concurrent pulses select the trigger WR input or read RD input functions Upon completing a conversion the processor system is notified by an interrupt request IRO from U2041 The timebase circuits receive video sample time delay values in digital form from the processor system and generate precisely timed strobes to the driver sampler circuits Digital counters determine the delay in 50 ns multiples and analog circuits further define the delay to fractions of that period A block diagram o
35. batteries should be fully recharged before further use Operating Instructions Low Temperature Operation NOTE Turn the POWER switch off after instrument shutdown to prevent continued discharge of the batteries Under low line voltage conditions the fuse ratings might be exceeded if the battery if fully discharged and a chart recording is being made Allow the battery to charge for about one hour before attempting to make a chart recording or use AC only When operating the 1502B in an environment below 10 C a heater will activate The element is built into the LCD module and will heat the display to permit normal operation Depending on the surrounding temperature it might take up to 15 minutes to completely warm the crystals in the LCD Once warmed the display will operate normally Preparing to Use the 1502B Check the power requirements remove the front cover and you are ready to test cables The following pages explain the front panel controls NE Tektronix 15028 XN SB A x7 POSITION TI 1avg 50 O2ft 00 EXT VOLTAGE NOISE FILTER VERT SCALE DIST DIV Vp
36. dB and Series Loss Any condition that makes the cable less efficient at delivering electrical energy than it was designed to be Water leaking through the insulation poorly mated connectors and bad splices are typical types cable faults see Reactance Cables are designed to match the source and load for the electrical energy that they carry The designed impedance 15 often called the characteristic impedance of the cable The arrangement of the conductors with respect to each other is the major factor in designing the impedance of cables Glossary 1 Glossary Conductor dB DC Dielectric Domain Impedance Impedance Mismatch Glossary 2 Incident Pulse Inductance Any substance that will readily allow electricity to flow through it Good conductors are metals such as silver copper gold aluminum and zinc in that order dB is an abbreviation for decibel Decibels are a method of expressing power or voltage ratios The decibel scale is logarithmic It is often used to express the efficiency of power distribution systems when the ratio consists of the energy put into the system divided by the energy delivered or is some cases lost by the system Our instrument measures return loss The formula for decibels is dB 2 log Vi V1 where Vi is the voltage of the incident pulse VI is the voltage reflected back by the load and log is the decimal based logarithmic function The dB vertical scale on our instr
37. 0579 02 214 0579 02 214 0579 02 156 2760 00 156 2763 00 156 1225 00 Effective B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 Serial No Discontd Qty Name amp Description B037260 B037260 B037260 B037260 B037260 B037260 B037260 B037260 B037260 B037260 B037260 B037260 B037260 B037260 CIRCUIT BD ASSY MAIN W O EPROM Con t RES FXD METAL FILM 15 0K OHM 196 0 2W RES FXD FILM 16 5K OHM 1 0 2W RES FXD FILM 35 7K OHM 1 0 2W RES FXD FILM 24 3 OHM 1 0 125W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD FILM 8 06K OHM 1 0 2W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD METAL FILM 2 00K OHM 1 0 2W RES FXD METAL FILM 15 0K OHM 1 0 2W RES FXD FILM 2 67K OHM 1 0 2W RES FXD FILM 200 OHM 1 0 2W RES FXD FILM 71 5K OHM 1 0 2W RES FXD METAL FILM 27 4K OHM 1 0 2W RES VAR NONWW TRMR 5K OHM 0 5W CERMET TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TER
38. 1 19 1 20 1 20 1 21 1 22 1 22 1 23 1 23 1 24 1 24 1 25 1 26 1 26 1 27 1 28 Contents Figure 2 1 Figure 2 2 Figure 2 3 Figure 2 4 Figure 2 5 Figure 2 6 Figure 2 7 Figure 2 8 Figure 2 9 Figure 2 10 Figure 2 11 Figure 2 12 Figure 2 13 Figure 2 14 Figure 2 15 Figure 2 16 Figure 5 1 Figure 5 2 Figure 5 3 Figure 5 4 Figure 5 5 Figure 5 6 Figure 5 7 Figure 5 8 Figure 5 9 Figure 5 10 Figure 5 11 Figure 5 12 Figure 5 13 Figure 5 14 Figure 5 15 Figure 5 16 Figure 5 17 Figure 5 18 Figure 5 19 Start up Measurement Display Measurement Display with 3 foot Cable Cursor at End 3 foot Cable Flat Line Display Out to 50 0004 Feet Flat Line Display at 2 000 ft Waveform Off the of the Display Waveform at the Bottom of the Display Waveform with Gain at 5 00 mp div of Pulse on Center Graticule Rising Edge of Incident Pulse in Left most cosine ete nen RUP UHR nd REP pal hua Waveform Centered Cursor at 0 000 ft Pulse Centered on Display Cursor on Lowest Major Graticule that Rising Edge tema ee TRUE IRE SENE SESS Cursor on Highest Major Graticule that Rising Edge cha SERE RES
39. 283 0067 00 283 0059 02 283 0059 02 281 0925 01 283 0238 00 281 0925 01 283 0421 00 283 0067 00 281 0925 01 281 0925 01 Effective B021135 B021135 1502B MTDR Service Manual Discontd Qty Name amp Description CIRCUIT BD ASSY MAIN W O EPROM Con t CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD ELCTLT 100UF 25V AXIAL CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD ELCTLT 10UF 50 20 25W VDC CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 0 1UF 2096 50V SQ CAP FXD CER DI 0 01UF 1096 50V SQ CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 0 001UF 1096 200V CAP FXD CER DI 1UF 20 50V CAP FXD CER DI 1UF 20 50V CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 0 01UF 10 50V SQ CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 0 1UF 80 20 50V CAP FXD CER DI 0 001UF 1096 200V CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U Mfr Code
40. 3 63 64 LIN LARA TARA LLG 5 lt v2 E NM V5 Scanning select pulse VLDC V 5 5 vp V5 VLDC 45 LP v5 VLDC Figure 5 18 Row Timing Diagram 5 34 1502B MTDR Service Manual Circuit Descriptions One Line P Extra m 1 16 16 1 16 1 64 16 1G 5 First Column Second Column Third Column Forth Column Driver Pair Driver Pair Driver Pair Driver Pair Enable Enable Enable Enable mE mE 64 LP gt rr y 5V Select Bits V Non Select Bits V Non Select Bits Vlcd Select Bits One Frame Figure 5 19 Column Timing Diagram 1502B MTDR Service Manual 5 35 Circuit Descriptions 5 36 The relevant outputs m Columns 1 to 64 These are the 64 outputs from the level shifter NOTE The manufacturer s pinout of the outputs are numbered in order of shift seg 63 seg 0 The nomenclature herein refers to the outputs in column order Therefore seg 63 correspon
41. 37 Circuit Descriptions Column Driver Interface CPU and Display Memory 5 38 Interface NOTE The manufacturer s nomenclature on the controller differs somewhat ST FRP LP LIP and FR FRMB Thee column drivers require more control and timing signals than the row driver These include XSCL D3 DO LP and FR ErN is required at the start of every line to enable the first leftmost as seen from the front of the display column driver pair is required once to latch in Ery and three times after that to enable the successive column driver pairs Each successive must occur every 16 XSCL pulses 1 after each column driver pair is full of 64 bits 4 X 16 bits XSCL is required 16 times per column driver pair per line to shift in the bit pattern data Therefore a total of 64 XSCL are required per line for the four column driver pairs XSCL 15 generated by U3030 a counter clocked by CLP or LP from the controller It must be generated as such because the controller was designed to use with 80 channel column drivers instead of 64 channel column drivers The controller version of is generated every 20 XSCL pulses rather than every 16 XSCL pulses as required by the 64 channel column drivers The counter is used to translate XSCL into As a consequence of generating as above must also be generated This is done with the U3065 flip flop pair
42. 47 5MM PNH POZ WSHR LOCK 4 SPLIT 0 025 THK SPACER SLEEVE 1 248L X 0 118 ID NYLON HEAT SINK ELEC BATTERY SPLY LOWER AL CKT BD ASSY SEE A9 REPL SOCKET PIN TERM U W 0 02 DIA PINS PLATE METALLIC W TAPS BATTERY 9 1 4V 200MA HEAT SINK ELEC BATTERY SPLY UPPER AL FUSE THERMAL SEE 9 9100 REPL Mfr Code 80009 0DWW6 06540 86928 80009 0J 9 4 0 472 80009 0 01 2K262 0 RZ5 0 RZ5 0 9P4 93907 0 260 73743 0KBO1 86928 80009 0J 9P4 00779 0 244 ODWW6 0 9P 4 Mfr Part Number 016 0813 00 016 0813 01 6130 SS 0632 5612 32 31 333 1990 00 333 1990 02 334 6867 00 211 0198 00 ORD BY DESCR 348 0432 00 348 1143 00 348 1143 01 331 2162 00 ORD BY DESCR 343 0349 01 12161 50 ORD BY DESCR ORD BY DESCR 361 0776 00 214 2344 00 50462 7 386 2435 00 146 0065 00 214 2343 00 10 15 Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont Fig amp Index Tektronix SerialNo Serial Mfr Number Number Effective Discontd Qty Name amp Description Code Number 10 16 1502B MTDR Service Manual Glossary Aberrations Cable Attenuation Cable Fault Capacitance Characteristic Impedance 1502B MTDR Service Manual Imperfections or variations from a desired signal In TDRs a pulse of electrical energy is sent out over the cable As the pulse ge
43. 6 11 Calibration NOTE If the instrument fails this check first refer to Zero Offset Adjust in the Adjustment Procedures section of this chapter If you are unable to adjust this satisfactorily refer to the Circuit Descriptions chapter and the Troubleshooting section of the Maintenance chapter of this manual Vertical Position Offset Check If the instrument fails only this check it can be used but should be serviced Not all waveforms will be viewable at all gain settings 1 Setthe front panel controls CABLE 3 ft precision cable NOISE FILTER 1 avg VERT SCALE 500 mp DIST DIV ft div Vp 99 2 Setthe POSITION control so the distance window reads 2 000 ft 3 Using the control verify that the entire waveform can be moved upward past the center graticule line _ 72 000 ft F Figure 6 19 Waveform at Top of the Display 4 Using the control verify that the entire waveform can be moved to the very bottom of the display The top of the pulse should be lower than the center graticule line 6 12 1502B MTDR Service Manual Calibration Noise Check 1502B MTDR Service Manual E MTM cg Figure 6 20 Waveform at Bottom of the Display S Remove the 3 ft precision cable 6 Connect the 50Q terminator to the CABLE connector 7 Center the pulse in the display The pulse should be two divisions high ac 2 000 f
44. 6 34 Rising Edge at Last Horizontal Graticule NOTE If the instrument fails this check refer to Troubleshooting in the Maintenance chapter and Driver Sampler in the Circuit Descriptions chapter of this manual NOTE If you have just completed the previous check the instrument might still be in HORZ SET REF mode This will not have any effect on the Jitter Check If you wish to exit HORZ SET REF either turn the power off and on re initializing the instrument or follow the directions for HORZ SET REF in the Operator chapter 1 Setthe front panel controls CABLE 500 terminator NOISE FILTER avg VERT SCALE 500 mp DIST DIV 1 ft div Vp 99 2 Using the POSITION and the POSITION controls center the rising edge of the pulse on the center horizontal graticule line 6 21 Calibration 6 22 200020101022 lt gt Figure 6 35 Rising Edge at Center of Display 3 Turn the VERT SCALE control clockwise for reading of more than 1 0 mp div Verify that the leading edge of the pulse moves less than five pixels 0 02 ft nO 131611 Figure 6 36 Rising Edge with Scale at 1 0 mp div You may also use the Max Hold function found in the Acquisition Control menu within the Setup menu This function can simplify this measurement for you by displaying jitter accumulating See the Operator chapter for directions on usin
45. 83385 86445 10 4 Manufacturer MINNESOTA MINING MFG CO GRACE W R AND CO POLYFIBRON DIV AIRMOLD KASO PLASTICS INC COOPER BELDEN ELECTRONICS WIRE amp CABLE BELDEN DIVISION AMCA INTERNATIONAL CORP CONTINENTAL SCREW CO DIV DZUS FASTENER CO INC FISCHER SPECIAL MFG CO JOHNSON E F COMPANY ILLINOIS TOOL WORKS INC SHAKEPROOF DIV WALDES KOHINOOR INC TEKTRONIX INC PARKER HANNIFIN CORP O SEAL DIV MICRODOT MFG INC GREER CENTRAL DIV PENN FIBRE AND SPECIALTY CO INC Address PO BOX 2963 BECKER FARMS INDUSTRIAL PARK PO BOX 610 11015 A NE 39TH 2200 US HIGHWAY 27 SOUTH PO BOX 1980 459 MT PLEASANT 425 UNION BLVD 111 INDUSTRIAL RD 299 10TH AVE SW ST CHARLES ROAD 47 16 AUSTEL PLACE 14150 SW KARL BRAUN DR PO BOX 500 10567 EFFERSON BLVD 3221 W BIG BEAVER RD 4343 G ST City State Zip Code AUSTIN TX 78769 2963 ROANOKE RAPIDS NC 27870 VANCOUVER WA 98662 RICHMOND IN 47375 NEW BEDFORD MA 02742 WEST ISLIP NY 11795 3123 COLD SPRING KY 41076 9749 WASECA MN 56093 2539 ELGIN IL 60120 LONG ISLAND CITY NY 11101 4402 BEAVERTON OR 97077 0001 CULVER CITY CA 90232 3513 TROY MI 48098 PHILADELPHIA PA 19124 4325 1502B MTDR Service Manual Replaceable Mechanical Parts Replaceable Mechanical Parts List d Tektronix Part Serial No Serial No Mfr Number Number Effective Discontd Qty amp Description Code Mfr Part Number FIG 10 1 CABINET 650 3676 00 1 COVER LID ASSY L
46. 9 30 Schematics Driver Sampler 9 31 Schematics Power Fuse Jack 9 32 Li 10 17 Frame Assemblies and Front Panel Controls 10 18 Power det ami ek wa e rapa ua 10 19 Batey Pack m 10 20 vii Contents List of Tables Shipping Carton Test 5 XV Pusey Voltage u uode rd y dry ae paq edo Y orb V 1 2 Vp of Various Dielectric Types 1 10 Operator Performance Checks Equipment Required 2 1 Specifications Electrical Characteristics 3 1 Specifications Environmental Characteristics 3 3 Specifications Physical Characteristics 3 4 Option Port Wiring Configuration 5 12 Row Driver Latch BIfs 5 33 Colum Diver Lateh Bs uu us u cuna 2292493259592 5 36 Controller Periods 5 37 Calibration Performance Check Equipment Required 6 1 Adjustment Procedures Equipment Required 6 24 Main Board Voltages Tolerances Test Point Locations 6 27 Maintenance Equipment Required 7 1 Power Cord Conductor Color Code 1 1 Sealne Materia
47. A4L2080 108 1032 00 COIL RF FXD 225UH 20 TOROIDAL 0 03 108 1032 00 A4L2081 108 1032 00 COIL RF FXD 225UH 20 TOROIDAL 0 RO3 108 1032 00 A4Q1030 151 0190 00 XSTR SIG BIPOLAR NPN 40V 200MA 300MHZ AMP 01295 SKA3703 A401060 151 1103 00 XSTR SIG DMOS N CH ENH 30V 50MA 45 OHM 17856 DM1140 SD210DE A402030 151 0271 00 XSTR SIG BIPOLAR PNP 15V 30MA 2 0GHZ AMP 01295 SKA4504 A4Q2040 151 0190 00 XSTR SIG BIPOLAR NPN 40V 200MA 300MHZ AMP 01295 SKA3703 402050 151 0188 00 XSTR SIG BIPOLAR PNP 40V 200MA 250MHZ AMP 03508 39 3162 A4R1010 315 0301 00 RES FXD FILM 300 OHM 596 0 25W 01121 CB3015 A4R 1020 315 0102 00 RES FXD FILM 1K OHM 596 0 25W 01121 1025 A4R 1030 315 0101 00 RES FXD FILM 100 OHM 596 0 25W 01121 1015 A4R 1031 315 0103 00 RES FXD FILM 10K OHM 596 0 25W 01121 CB1035 A4R 1040 321 1249 00 RES FXD FILM 3 88K OHM 1 0 125W 01121 ADVISE A4R 1041 321 0612 03 RES FXD FILM 500 0HM 0 25 0 125W 19701 5033RC500R0C A4R 1042 311 1921 00 5 NONWW TRMR 250 OHM 1096 0 5W 02111 635251 602 A4R 1050 322 3308 00 RES FXD FILM 15 8K OHM 196 0 2W 57668 CRB20FXE 15K8 4 1051 322 3289 00 RES FXD METAL FILM 10K OHM 1 0 2W 57668 CRB20FXE A4R 1052 315 0101 00 RES FXD FILM 100 OHM 596 0 25W 01121 015 A4R 1053 315 0101 00 RES FXD FILM 100 OHM 596 0 25W 01121 81015 A4R 1060 322 3331 00 RES FXD METAL FILM 27 4K OHM 1 0 2W 57668 CRB20FXE 27K4 A4R 1061 322 3289 00 RES FXD METAL FILM 10K OHM 1 0 2W 57668 CRB20FXE A
48. Assembly as previously described Remove the ribbon cable on the Main Board that connects the Main Board to the Option Port Assembly Remove the screw and washer from the instrument side panel Remove the nut from the bottom of the instrument The Option Port Assembly may be disassembled further by removing the four screws from the back of the assembly This will allow easy access for replacement of the Option Port connector When encountering difficulties with the instrument first use the troubleshooting chart in the Operation chapter This might eliminate any minor problems such as fuse or power problems The following troubleshooting flow charts starting on page 7 17 are designed to give you an idea where to start The Circuit Descriptions and Schematics chapters will give further assistance toward solving the problem 1502B MTDR Service Manual Maintenance The Main Board waveforms represented on the flow chart are representative of an instrument in operation per the setup at the top of the flow chart Additional Main Board waveforms are also included in this section Test Point Waveforms The following Main Board waveforms are similar to the waveforms found on the troubleshooting flow chart In some cases however the oscilloscope was set to show timing rather than the detail of the waveform For example TP7010 on the flow chart shows the detail of the pulse but the same test point in the following figures shows the repet
49. BNC female to male 103 0158 00 Connector BNC male to F female 013 0126 00 Connector BNC female to GR 017 0063 00 Connector BNC male to GR 017 0064 00 Terminator 756 011 0102 00 Adapter Direct Current 015 0327 00 Adapter 50 75 017 0091 00 oa aa 017 0092 00 Adapter 20 1290 017 0090 00 These adapters should be purchased if GR connectors 017 0063 00 and or 017 0064 00 are purchased 4 3 Options and Accessories 4 4 1502 Service Manual WARNING The following servicing instructions are for use only by qualified personnel To avoid injury do not perform any servicing other than that stated in the operating instructions unless you are qualified to do so Refer to all Safety Summaries before performing any service WWW WW W WW W WW W W AAA AAA 0 A A A V A AWA Circuit Descriptions Introduction 1502B MTDR Service Manual This chapter describes how the instrument works First is a circuit overview and how it relates to the block diagram Figure 5 1 next page Following that are the separate sections of the instrument discussed in detail The 1502B uses time domain reflectometry techniques to
50. C2031 C2032 C2033 C2034 C3010 C3020 C3021 C3022 C3023 C3030 T C3031 T C3032 C3033 C3034 J1020 T J3030 T PS2030 T Q1020 Q1030 Q2020 R1010 R1011 R1012 R1013 R1014 R1020 T Back Side Components 9 8 CIRCUIT NUMBER R1021 R1022A R1022B R1023 R1024 R1025 R1026 R1027 R1030 R1031 R2010 R2020 R2021 R2022 R2024A R2024B R2030 R2031 R2032 R2034 R2035 R2036 R2037 R2038 R3010 R3011 R3020A R3020B R3024 R3031 S1010 S1011 S2010 S2011 S3010 S3012 S3020 S3021 S3022 U2010A U2010B PAGE SCHEM CIRCUIT SCHEM LOCATION NUMBER PAGE SCHEM BRD U2020A U2020B U2021 U2022A U2022B U2022B U2022G U2023 U2024 U2025 U3020A U3020B U3020C U3020D U3021A U3021B U3021C U3021D U3022A U3022B U3022C U3022D U3023A U3023B U3023C U3023D U3025 03031 15028 MTDR Service Manual Diagrams 1 POWER SUPPLY CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD x I I a MM P C1010 T C1011 C1012 C1013 C1014 C1015 C1016 C1030 C1031 C1032 C1033 C1034 C1035 C1036 C1037 C1038 C2010 C201 1 C2012 C2013 C2020 C2021 C2022 C2023 C2024 C2025 C2030 C2031 CR1010 CR1011 CR1030 CR1031 CR1032 CR1033 CR1034 T Back Side Components 1502B MTDR Service Manual CR2010 CR2011 CR2012 CR201
51. CAP FXD CER DI 1000PF 5 200V CAP FXD CER DI 0 1UF 20 50V CAP FXD CER DI 0 1UF 20 50V DIODE DVC DI SCHOTTKY SI 15V 1 2P F DIODE SIG ULTRA FAST 40V 150MA 4NS 2PF DIODE SIG ULTRA FAST 40V 150MA 4NS 2PF DIODE DVC DI S CHOTTKY SI 15V 1 2PF DIODE DVC DI SW S1 55V 200MA DO 351N461D DIODE DVC DI SW S1 55V 200MA DO 351N461D DIODE DVC DI SW S1 55V 200MA DO 351N461D DIODE DVC DI SCHOTTKY 51 15 1 2 DIODE DVC DI SCHOTTKY 51 15 1 2 Mfr Code 04222 01002 55680 0 985 0 985 04222 31433 04222 31433 0 9R5 0 985 04222 04222 04222 04222 0 9R5 0 985 04222 31433 04222 31433 04222 04222 21847 01295 01295 21847 03508 03508 03508 21847 21847 Mfr Part Number SA105E104MAA 61F10AC332 UVX1V4R 7MAAITD CEUSM1V101 CEUSM1V101 W1206C102K3B04 322 102 2G5CA W1206C102K3B04 322 102 2G5CA CEUSM1V101 CEUSM1V101 SA105E104MAA SR201A511GAA SA105E104MAA SA105E104MAA CEUSM1V101 CEUSM1V101 W1206C102K3B04 C322C102 2G5CA W1206C102K3B04 322 102 2G5CA SA105E104MAA SA105E104MAA A2X600 1N4152R 1N4152R A2X600 DJ 2011 DJ 2011 DJ 2011 A2X600 A2X600 8 31 Replaceable Electrical Parts Replaceable Parts List Cont Assy Tektronix Serial No Serial No Mfr Number Part Number Effective Discontd Qty amp Description Code Part Number 4 670 9291 BD ASSY S R DRIVER SAMPLER Con t A4 3040 131 3360 00 CONN HDR PCB MALE STR 2 X 10 0 1 CTR 53387 3592 6002
52. CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 04UF 20 50 CAP FXD CER DI MLC 0 22UF 20 50 250 CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD ELCTLT 10UF 50 20 25W VDC CAP FXD CER 01 1000 5 200 SQ CAP FXD CER DI 1000PF 5 200V SQ Mfr Code 31433 04222 31433 04222 04222 31433 31433 04222 04222 16546 31433 31433 0 985 31433 04222 04222 16546 31433 31433 04222 04222 04222 31433 31433 04222 31433 04222 31433 31433 0 985 31433 31433 Mfr Part Number C114C224M5Y5CA SR305E105ZAA C114C224M5Y5CA SR595C104MAAAP1 SA105E473MAA C114C224M5Y5CA C322C102J2G5CA SR305E105ZAA SR305C105MAATRSTDII CN15C101J C114C224M5Y C114C224M5Y CEUSTIE100 C114C224M5Y 5CA SR305E503ZAA SA101A510GAA CN15C101J C114C224M5Y 5CA C312C109D1G5EA SR152E102ZAA SR595C104MAAAP 1 SA105E473MAA C322C102 2G5CA C114C224M5Y5CA SA105E473MAA C114C224M5Y5CA SA105E473MAA C114C224M5Y5CA C114C224M5Y5CA CEUST1E100 C322C102 2G5CA 322 102 2G5CA 8 11 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1C9034 A1A1C9035 A1A1CR1020 A1A1CR1021 1 1 1022 1 1 1023 1 1 3031 A1A1CR 4030 A1A1CR4031 1 1 4032 A1A1CR5030 A1A1CR5040 A1A1CR8020 A1A1CR9010 2010 A1A1 5040 A1A1J 9010 A1A1L5030 A1A1L5040 A1A1M1030 A1A1Q1010 A1A1Q1020 A1A1Q1021 A1A1Q1030 A1A1Q1031 A1A1Q2011 A1A1Q2012 8 12 Tektr
53. COUNTER SYNCH 4 BIT DIGITAL HCTCMOS GATE QUAD 2 INPUT AND IC LINEAR 12 BIT PLUS SIGN 1205 IC DIGITAL ALSTTL FLIP FLOP DUAL J K Mfr Code 0 R04 0 R04 01295 0 R04 27014 04713 27014 04713 01295 01295 04713 01295 04713 27014 09922 01295 01295 01295 01295 04713 01295 04713 34649 75378 01295 01295 01295 01295 01295 34371 27014 01295 Mfr Part Number TC5564P L 20 TC5564P L 20 SN74HC138N TMPZ84C00AP 6 MM74C30N MC74HC14N MM74C240 78105 SN74HC20N SN74HC74N MC74HC27N SN74HC32N MC74HC245AN MM 74HC244N DILB28P 108 SN74HC138N SN74HC138N SN74HC74N SN74HC138N MC74HC113N SN74HC138N MC74HC113N P82C54 556 31 207 SN74ALS175N 14415113 SN74ALSO2N SN74ALS 175N SN74ALS 161BN CD74HCT08E17 ADC1205 14415113 8 19 Replaceable Electrical Parts Replaceable Parts List Cont Assy Tektronix Serial No Serial No Mfr Number Part Number Effective Discontd Qty amp Description Code Mfr Part Number 1 1 670 9285 CIRCUIT BD ASSY MAIN W O EPROM A1A1U2043 156 2421 00 IC DIGITAL HCMOS FLIP FLOP QUAD D TYPE 04713 MC74HC175N 1 102044 156 3107 00 IC DIGITAL HCMOS FLIP FLOP OCTAL D TYPE 01295 SN74HC374N A1A1U2045 156 1752 00 IC DIGITAL FTTL GATE TRIPLE 3 INPUT 04713 MC 74F10N A1A1U2046 156 3151 00 IC INTFC CMOS D A CONVERTER 24355 AD7534 N A1A1U3010 156 3107 00 IC DIGITAL HCMOS FLIP FLOP OCTAL D TYPE 01295 SN74HC374N A1A1U3020 156 2
54. Code 80009 80009 57668 01121 01121 57668 57668 57668 57668 01121 01121 57668 57668 57668 32997 57668 57668 57668 91637 57668 57668 57668 57668 57668 57668 91637 57668 91637 57668 57668 57668 57668 Mfr Part Number 321 0523 00 321 0523 00 CRB20 FXE 348K 210A103 ADVISE CRB20 FXE 100E CRB20 FXE 20 0 CRB20 FXE 100K CRB20 FXE 100K 2104103 2104103 CRB20 FXE 3K01 CRB20 FXE 3K01 CRB20 FXE 11K0 3329H L58 501 CRB20 FXE 274E CRB20 FXE243E CRB20 FXE243E CCF501G 200R OF CRB20 FXE 100E CRB20 FXE 12K1 CRB20 FXE 100E CRB20 FXE 49K9 CRB20 FXE 24 9 CRB20 FXE 511E CCF50G5111FT CRB20 FXE CCF50 1 633200F CRB20 FXE 18K2 CRB20 FXE 15K0 CRB20 FXE 24 9 CRB20 FXE 100K Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1R3041 A1A1R3042 A1A1R4020 1 184021 A1A1R4022 A1A1R4023 A1A1R4030 A1A1R4031 A1A1R4032 A1A1R 4040 A1A1R4041 A1A1R4042 A1A1R4043 A1A1R4044 A1A1R4045 A1A1R 4046 A1A1R4047 A1A1R 4048 A1A1R5020 A1A1R5021 A1A1R5022 A1A1R5023 A1A1R5024 A1A1R5025 A1A1R5026 A1A1R5030 A1A1R5031 A1A1R5032 A1A1R5033 A1A1R5034 A1A1R5035 A1A1R6030 Tektronix Part Number 670 9285 322 3126 00 322 3113 00 322 3297 00 322 3261 00 322 3385 00 322 3341 00 322 3126 00 322 3325 00 322 3261 00 322 3281 00 322 3134 00 322 3135 00 321 0136 00 322 3131 00 322 3138 00 322 3139 00 322 3141 00 322 3001 00 322 3395 UT 322 3289
55. DIST DIV control to 0 2 ft div 6 Adjust the gt POSITION control until the rising edge of the pulse is in the left most major division on the display 7 Move the cursor to 0 000 ft with the d gt POSITION control the aberration except the one under the cursor should be within one division of the center graticule line see Figure 6 30 next page 1502B MTDR Service Manual Calibration Risetime Check 1502B MTDR Service Manual i m M lam EET Figure 6 30 Waveform at 5 mp div 8 Increase the DIST DIV to 200 ft div 9 Increase the VERT SCALE to 5 00 mp 10 Verify the the waveform is flat one minor division after the incident step NOTE If the instrument fails this check refer to Driver Sampler in the Circuit Descriptions chapter and the Troubleshooting section of the Maintenance chapter If the risetime is out of specification it might be difficult to make accurate short distance measurements near the front panel and might affect the resolution of the instrument 1 Setthe front panel controls CABLE 500 terminator NOISE FILTER avg VERT SCALE 500 mp DIST DIV 0 1 ft div Vp 99 10918 0 rus F 0 Figure 6 31 Incident Pulse Center of Display 6 19 Calibration 6 20 Use the POSITION control to move the incident pulse to the center of the display as shown in Figure 6
56. MENU again Scroll to Max Hold is Off and push MENU again This line will change to Max Hold is On The monitoring function is now ready to activate 6 Repeatedly push MENU until the instrument returns to normal operation 1 25 Operating Instructions Pulse On Off 1 26 Figure 1 30 Waveform Viewed in Normal Operation 7 When you are ready to monitor this cable for intermittents push STORE The 1502B will now capture any changes in the cable 0 000 ft u x changes JU Figure 1 31 Waveform Showing Intermittent Changes 8 exit monitor mode push STORE again 9 To exit Max Hold access the Acquisition Control Menu again turn off Max Hold and push MENU repeatedly until the instrument returns to normal operation This feature puts the 1502B in a listening mode by turning off the pulse generator 1 Attach a cable to the 1502B front panel CABLE connector Push MENU to access the Main Menu A 3 Scroll to Setup Menu and push MENU again 4 Scroll to Acquisition Control Menu and push MENU again 5 Scroll to Pulse is On and push MENU again This will change to Pulse is Off 1502B MTDR Service Manual Operating Instructions Single Sweep 1502B MTDR Service Manual 002002020020 00008 Figure 1 32 Waveform Display with No Outgoing Pulses 6 Repeatedly press MENU until th
57. Nd RUN Jitter Leading Edge Incident Pulse Jitter Captured Using Max Hold System Block Diagram Waveform Accumulation Diagram Power Supply Block Diagram Processor Block Diagram Option Port Interface Block Diagram Video Processor Block Diagram Video Processor Timebase Block Diagram Timebase Control Combined Effects of Time Delay Calibration of Delay Zero and 50 ns Analog Delay Driver Sampler Block Diagram Front Panel Block Diagram Display Module Block Diagram NDE Cell deer deers wlha Row Driver Block Diagram Column Driver Block Diagram Row Timing Diagram Column Timing Diagram 2 2 2 2 2 3 2 3 2 4 2 4 2 5 2 5 2 7 2 7 2 8 2 8 1502B MTDR Service Manual Contents 1502B MTDR Service Manual Figure 5 20 Figure 5 21 Figure 6 1 Figure 6 2 Figure 6 3 Figure 6 4 Figure 6 5 Figure 6 6 Figure 6 7 Figure 6 8 Figure 6 9 Figure 6 10 Figure 6 11 Figure 6 12 Figure 6 13 Figure 6 14 Figure 6 15 Figure 6
58. Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A2 A2R3010 A2R3011 A2R3020 A2R3024 A2R3031 A2RT2038 A251010 A251011 A252010 252011 253010 253012 253020 253021 253022 A2U2010 A2U2020 A2U2021 A2U2022 A2U2023 A2U2024 A2U2025 A2U3020 A2U3021 A2U3022 Tektronix Part Number 672 1251 322 3385 00 322 3385 00 311 2400 00 307 0504 00 307 0504 00 307 0751 00 260 2091 00 260 2091 00 260 2091 00 260 2091 00 260 2091 00 260 2269 00 260 2269 01 260 2270 00 260 2270 01 260 2287 00 260 2287 01 260 2269 00 260 2269 01 156 0853 00 156 1225 00 156 1367 00 156 2463 00 156 2589 00 156 2758 00 156 2758 00 156 2026 00 156 2026 00 156 2026 00 Serial No Effective R010100 B020820 R010100 B020820 R010100 B020820 R010100 B020820 1502B MTDR Service Manual Serial No Discontd Qty Name amp Description B020819 B020819 B020819 B020819 CIRCUIT BD ASSY FRONT PANEL Con t RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES VAR PLASTIC DUAL 10K 10 NO STOPS RES NTWK FXD FI 15 300K OHM 296 0 125W RES NTWK FXD FI 15 300K OHM 296 0 125W RES THERMAL 20K 5 SWITCH PUSH 1 1 POLE RECORD SWEEP SWITCH PUSH 1 1 POLE RECORD SWEEP SWITCH PUSH 1 BTN 1 POLE RECORD SWEEP SWITCH PUSH 1BTN 1 POLE RECORD SWEEP SWITCH PUSH 1 1 POLE RECORD SWEEP SWITCH ROTARY NOISE P
59. The flip flop pair is set when LP and LEO are asserted and hold set until XSCL CLP shifts in a logic 0 after the pulse Ery is held high for a duration long enough to enable the first column driver pair There are two data buses and two address buses on the controller The first data bus DB7 DBO is used to access registers internal to the controller These internal registers are used to initialize the controller The second data bus RD7 RD0 is used to read bit pattern data from the display memory The data bus from the display memory is tied directly to the RD7 RDO data bus and indirectly through a bidirectional bus transceiver U1050 to the DB7 DBO data bus The DB7 data bus is tied directly to the CPU data bus through the 40 pin connector The first address bus MA12 is tied to the display memory and addresses it MAI2 MAO can have one of two sources The first is an internal address in the controller which is the address of the currently accessed bit pattern data byte The second Is the address resent on the second address bus A11 AO 1502B MTDR Service Manual Circuit Descriptions D7 DO x X x X Read Data from Internal Register Write Data to Internal Register Read and Write for Internal Register Timing H on RAM OE on RAM x X A Head Data from Wr
60. a filling of liquid crystal material A plating of indium tin oxide on the back plane of glass is used as a heater but is not used in the display process Electrically the cell is a 128 X 256 pixel display each pixel being an intersection of a row and a column These intersections are like small capacitors When a non select voltage about 1 5 VRMS is applied to a row and a column their intersection is turned off see Figure 5 15 next page That is light is allowed to pass through the display and reflect back from the transflector creating an off pixel A select voltage about 1 7 VRMS turns the intersection on That is the light is not allowed to pass through the crystalline material and is therefore not reflected back from the transflector creating an on pixel 1502B MTDR Service Manual Circuit Descriptions JJ 2 O 2 D I m 2 ae oe HN COLUMN 1 1 COLUMN 2 HN COLUMN 255 E COLUMN 256 LOWER HALF UPPER HALF SCREEN SCREEN Figure 5 15 SBE Cell Row and Column Drivers There is one row driver located on the Row Driver Controller Board There are eight column drivers located on the Column Driver Board The row and column drivers receive control timing and data signals from the controller and translate them to properly timed voltages that are p
61. bank is addressed 15 set by flip flop U2030A This bank switching flip flop can be toggled by the processor with two select lines decoded in the enable and select signal address space The select signal for the EPROM is generated by combined address line A15 with the MREQ signal in U1045A Whenever the processor addresses a location where A15 is not set the program memory will be selected to place data on the bus The first RAM is eight kilobyte memory U1021 selected by a signal generated by 1 of 8 decoder 01022 This decoder operates on the three most significant address bits A15 A14 A13 in combination with MREQ Each of its decodes represents a selection of a particular g th of addressable locations The first four decode signals are not used because they are located in the program memory space The fifth decode is the select signal for the first RAM occupying locations SOOOH to 9FFFH The second RAM is also an 8 kb memory U1020 made non volatile by lithium battery 1010 and non volatile memory controller 01010 The select signal for this RAM is generated similarly to that for the first RAM with the sixth g th decode of U1022 This decode occupies AOOOH to BFFFH The display RAM is also an 8 kb memory U1040 located in the display module It is selected by the seventh decode of U1022 It occupies locations COOOH to DFFFH The remaining addressable space is used to generate enable select or trigger signals which read wr
62. digitized and stored in the processor until sufficient points are accumulated to define the entire period of interest The samples are then processed and displayed at a much slower rate forming the recombined waveform as shown This process allows the presentation of waveforms too rapidly to be viewed directly Cable voltage n samples Recombined samples Figure 5 2 Accumulation Diagram Voltage samples from the driver sampler are combined with a vertical position voltage derived from the front panel control then amplified The amplifier gain is programmed by the processor to give the selected vertical sensitivity Each amplified sample voltage is then digitized by an analog to digital converter and stored in the processor memory When the processor has accumulated sufficient samples 251 to form the desired waveform the samples are formatted This formatted data is then transferred to the display memory The display logic routes the data to each pixel of the LCD where each digital data bit determines whether or not a particular pixel is turned on or off Between each waveform samples are taken at the cursor location for the ohms at cursor function and at the leading edge of the incident step for use by the timebase correction circuit Cursor and readout display data is determined by the proces
63. distance gt 1 5 ft continued next page 1502B MTDR Service Manual 3 1 Specifications Characteristic Cursor Ohms Readout Range Resolution Accuracy Horizontal 9 cales Range Performance Requirement Supplemental Information 100160 3 significant digits 10 with serial cable impedance correction relative impedance measurements 290 11 values 1 2 5 sequence 0 1 ft div to 200 0 025 m div to 50 m div ftto 2 000 ft 2 5 m to 500 m Horizontal Position Vp Range Resolution Accuracy Custom Option P ort Within 1 Any distance to full scale can be moved on screen Propagation velocity relative to air 0 30 to 0 99 0 01 Included in total timebase error tolerance Tektronix Chart Recorders YT 1 and YT 1S are designed to operate with the 1502B Produces a high resolution thermal dot matrix recording of waveform and switch values Line Voltage 115 VAC 90 to 132 VAC 45 to 440 Hz or Fused at 0 3 230 VAC 180 to 250 VAC 45 to 440 Hz or Fused at 0 15 12 VDC through battery pack connector Battery Pack Operation 5 hours minimum 20 chart recordings maximum 15 to 425 C charge and discharge temp Full Charge Time Overcharge Protection Discharge Protection Charge Capacity Charge Indicator 3 2 LCD backlight off Operation of instrument with backlight on or at temps below 10 C will degrade battery operation specification
64. feature allows zeroing the dB scale at whatever pulse height is desired 1 Turn NOISE FILTER fully counterclockwise Set will appear in the noise averaging area of the LCD 2 Adjust the incident pulse to the desired height e g four divisions It might be necessary to adjust SPOSITION E MN 0 set vertical scale and press STORE F Figure 1 26 Incident Pulse at Three Divisions 3 Push STORE 4 Return NOISE FILTER to the desired setting Notice that the vertical scale now reads 500 mp div NOTE The millirho vertical scale will not be in calibration after arbitrarily adjusting the pulse height 1 23 Operating Instructions Vertical Compensation for Higher Impedance Cable 1 24 The millirho scale 15 the reciprocal of the number of divisions high the pulse has been set For example 1 pulse divided by 4 divisions equals 0 25 or 250 mp div When testing cables other than 50C this procedure allows reflection measurements in millirho 1 Attachashort sample of the given cable 750 in this example to the instrument ac x 19 200 ft 0 F F pied vos F F Figure 1 27 Waveform of Short 750 Cable 2 Adjust the 9 gt POSITION control to position the reflected pulse at center screen 3 Turn NOISE FILTER to VERT SET REF 4 Adjust VERT SCALE so the reflected pulse from open at far end of cable samp
65. for the circuit boards in the instrument Corresponding to each circuit number is a schematic page reference the locator for that schematic page and the locator for the circuit board The locator lists are given for each circuit board ordered by that board s assembly number An example entry is as follows Schematic Schematic Board Page Locator Locator C10306 2B D8 C1 Read Capacitor C10306 is found on schematic 2B in grid D8 Its physical location is grid C1 on the circuit board A locator list and circuit board grid are also given on each circuit board illustration Graphic symbols and class designation letters are based on ANSI standards Logic symbology reflects the actual part function not the logic function performed Therefore logic symbols should reflect manufacturer s data Electrical components shown on the diagrams are in the following units Resitstors Ohm Q Diagrams 9 2 Component Number Capacitors Farad F Inductors Henry H All capacitors and inductors indicatate their units resistors only indicate the appropriate scale factor Scale factors are given by the following standard M mega 106 k kilo 10 m milli 10 2 u micro 10 6 n nano 107 p pico 10 12 A numbering method is used to identify assemblies subassemblies and parts example of this numbering method and typical expansions is as follows A23A2R1234 A23 A2 R1234 l 4 Assembly Subassembly Circ
66. less than 10 000 feet 3 1 m 8 Setthe DIST DIV control to 1 ft div 0 025 m div 9 Turn the POSITION control counterclockwise until the distance window shows a distance of 2 000 feet 0 611 m 2 3 Operator Performance Checks T Figure 2 5 Flat Line Display at 2 000 ft This last step has set up the Instrument for the next check 2 Vertical Position Ifthe instrument fails this test it can be used but should be serviced when possible Offset Check Not all of the waveforms will be viewable at all gain settings 1 Using the POSITION control verify that the entire waveform be moved to the very top of the display off the graticule area 72000ft x Waveform off display Figure 2 6 Waveform Off the Top of the Display 2 Using POSITION control verify that the entire waveform be moved to the very bottom of the display to the bottom graticule line 2 4 1502 MTDR Service Manual Operator Performance Checks 3 Noise Check 1502B MTDR Service Manual WM s Waveform Figure 2 7 Waveform at the Bottom of the Display If the instrument fails this check it can still be usable for measurements of large faults that do not require a lot of gain but send the instrument to be serviced when possible A great deal of noise reduction can be made using the NOISE FILTER control
67. lt b Lp 5 v _ 64 Bit Level Shifter Fr Gnd Column X Column X 64 Figure 5 17 Column Driver Block Diagram The row driver 15 80 pin flat pack located on the Row Driver Controller Board It is composed of a 64 bit shift register 02020 64 bit latch and 64 bit level shifter The row driver has the following relevant Inputs W ST start pulse Input to the shift register Din on SED 1190 LP latch pulse LATCH Falling edge triggered this shifts data in the shift register and latches contents of the shift register into the latch Y 5 on SED 1190 1502B MTDR Service Manual Circuit Descriptions Column Driver 1502B MTDR Service Manual m FR frame signal Defines the select and non select voltages The relevant outputs Row 1 through 64 are paralleled outputs driving both sides of the display One set of outputs drive rows 1 through 64 and the other set drive rows 65 through 128 on the LCD Supply Voltages include the following m 5 VDC supply voltage for logic and select drive voltage non select drive voltage V5 non select drive voltage Vr cp Select voltage GND return for 5 VDC To perform its function the row driver receives a start pulse at the beginning of a frame LP shifts this start pulse into the shift register The contents are then transferred to the latch The level shifter shifts the logical Is and Os in the latch into select and non select volta
68. of jitter on the trigger signal The OR output can be observed at TP3020 Power Supply Conditioner There are seven power supplies for the hybrid 5 Vs 5 Vp 12 V and 0 6 V 5 24 The 5 supplies come on board as 5 so they require no regulation but are merely filtered before being used by the hybrid and the board The 12 V supplies enter the board as 15 V so the necessary filtering and regulation is accomplished by 03070 and associated circuitry The 0 6 V supply is used by the hybrid to set 1502B MTDR Service Manual Circuit Descriptions Front Panel Introduction Push Button Switches and Latches 1502B MTDR Service Manual the output step height It is referenced to the 5 V supply and controlled by U1050B and Q1030 The 40 6 V supply is adjustable via R1042 to allow the offset of the step generator to be zeroed out CR1040 temperature compensates the 40 6 V supply against variations in the hybrid The test points for these supplies are as follows 5 V TP1083 5 V TP1084 12 V TP1080 12 TP1081 0 6 V TP1030 Ground TP1082 The Front Panel Board consists of the following circuits for these controls Push Button Switches and Latches Rotary Binary Switches Resistive Shaft Encoders Analog to Digital Converter for Shaft Encoders The Front Panel Board consists of the following circuits for the display module m Electroluminescent Backlight Switch and Power Supply m Display Heater Circuitry m
69. operate the product without the covers and panels properly installed 1502B MTDR Service Manual 2 Service Safety Summary Do Not Service Alone Disconnect Power Use Care When Servicing With Power On Disposal of Batteries 1502B MTDR Service Manual Only qualified personnel should perform service procedures Read this Service Safety Summary and the General Safety Summary before performing any service procedures Do not perform internal service or adjustments of this product unless another person capable of rendering first aid and resuscitation is present To avoid electric shock disconnect the main power by means of the power cord or the power switch Dangerous voltages or currents may exist in this product Disconnect power remove battery and disconnect test leads before removing protective panels soldering or replacing components To avoid electric shock do not touch exposed connections This instrument contains a NiCad battery pack Some states and or local jurisdictions might require special disposition recycling of this type of material in accordance with Hazardous Waste guidelines Check your local and state regulations prior to disposing of an old battery pack Tektronix Factory Service will accept 1502B batteries for recycling If you choose to return the battery to us for recycling the battery cases must be intact the battery should be packed with the battery terminals insulated against possible short circu
70. operating b Turn the instrument on and allow it to warm up for at least five minutes If the instrument was already on e g you are performing this adjustment immediately after steps 1 11 then cycle the power off then back on again to return it to default settings c Whilea waveform is on the display adjust R1018 on the Front Panel Board counterclockwise until most of the display has dimmed 1502B MTDR Service Manual Calibration Figure 6 60 Waveform with Contrast Too Light d Startrotating R1018 slowly clockwise until all of the pixels are just visible on the display If you go too far restart the adjustments at step c e Rotate R1018 one quarter turn clockwise past the point of step d NOTE It is important to always determine the proper contrast setting by coming from a faded display It takes a higher threshold voltage to turn a pixel on than it does to turn one off If it is done from the other direction the display will be too bright f Inspect the display for any bleeding areas that are too dark or any fading areas that are too light Turn the instrument off h After waiting a few seconds turn the instrument back on i Reinspect the display for bleeding or fading Readjust R1018 if necessary ff 0150 0 0008 Figure 6 61 Waveform with Contrast Adjusted Correctly 1502B MTDR Service Manual 6 37 Calibration Zero Offset Adjust 6 38 If Contra
71. position of the knob As the control 15 rotated these values and the bar graph will change The lower value in each column should be between 0 and 10 while the higher number is between 245 and 255 Front Panel Diagnostic test all switches Hold down MENU button to Exit Switch 35 temp 82 Vp 0 99 Corresponding lt I gt Control 0 142 44 Numbers Graph A Control 12 181 Vertical Scale 172 8 0 0 000000800 1000 00000000000000000000000000 Figure 6 8 Front Panel Diagnostic Display 1502B MTDR Service Manual Calibration Thermistor Conclusion 12 Rotate the SPOSITION control slowly in either direction The lower value in each column should be between 0 and 10 while the higher number is between 245 and 255 13 Rotate the VERT SCALE control slowly in either direction The lower value in each column should be between 0 and 10 while the higher number is between 245 and 255 There is a numerical reading from the thermistor located on the LCD If it 15 not operating properly the LCD heater might not come on in cold environments This could result in slow or unreadable displays 1 The displayed temperature reading should be between 50 and 90 depending on the ambient temperature If the thermistor is defective the reading will be near 0 or 255 Front Panel Diagnostic test all switches Hold down MENU button to Exit 5 witch 1 temp 78
72. regulator is a boost switching regulator that increases its input voltage to a constant 16 2 VDC output This voltage is supplied directly to the processor for large loads such as the display heater electroluminescent backlight and options port The post regulator also supplies a DC to DC converter that generates 5 VDC and 15 VDC for use in the instrument Status signals indicating whether the instrument 15 running on AC line voltage or the battery pack and if the battery pack is approaching turn off level are supplied to the instrument by the deep discharge protection circuits The AC line power is received by the connector in the EMI filter FL1 This filter prevents high frequency signals generated in the instrument from being conducted back to the AC power line The line voltage is fused F101 and switched 5201 to the primary step down transformer T201 Both the switch and the fuse can be accessed from the outside of the instrument via covers on the rear of the cabinet The primary of T201 is wound in two identical sections These sections are connected by 5201 in parallel for 110 VAC operation or in series for 220 operation The secondary of T201 is connected by a short two wire cable to the Power Supply Board The MOV R101 across one of T201 s primaries protects the power supply if 220 VAC 15 applied while 52011 is in the 110 position Fuse F101 will open in this event 9 5 Circuit Descriptions 5
73. remove the battery pack If the instrument is shipped the battery pack should be removed If the instrument is stored with the battery pack installed the battery pack should be charged every 30 days A fully charged battery pack will lose about 50 of its capacity in three to four months if stored between 20 C and 25 The batteries can be damaged by reverse charging This can occur when an individual cell becomes discharged before the others and current from the other cells flows in a reverse direction through the discharged cell Reverse charging might develop because of individual cell aging partial charging of the battery pack or if a single cell has been replaced rather than the entire pack If the battery 15 low it will be indicated on the LCD bat low If this 15 the case protective circuitry will shut down the 1502B within minutes Switch to AC power change the battery or work very fast If the instrument 15 equipped with a chart recorder using the recorder will further reduce the battery level or the added load might shut down the instrument 1 111 Fy Indicator n 1 avg 500 5008 _ Figure 1 2 Display Showing Low Battery Indication Protection circuits in the charger prevent deep discharge of the batteries during instrument operation The circuits automatically shut down the instrument whenever battery voltage falls below approximately 10 V If shutdown occurs the
74. signal at the input node of 08041 Resistor T8045 determines the gain of 0804 1 and is paralleled with C8040 to reduce high frequency gain for noise reduction The sampled video input may be observed at TP9041 Combined video from the summing amplifier is further amplified by a three stage programmable video amplifier The first stage of this amplifier consists of amplifier 07040 voltage divider T8040 through R8043 and analog multiplexer U8040 Voltage gains of 0 16 32 or 48 dB are achieved by switching U8040 to connect one of the four points from the resistive voltage divider to the inverting input of U7040 This causes the amplifier gain to be equal to the attenuation factor of the voltage divider point selected The second stage consists of amplifier U5040 voltage divider R6040 through R6047 and analog multiplexer U6040 This stage operates similar to the first stage except eight voltage gains are provided from 0 to 14 dB in 2 dB steps The third stage consists of amplifier 03042 voltage divider T4040 through R4047 and analog multiplexer 04040 This stage operates similar to the first and second stages except eight voltage gains are provided from 0 to 1 75 dB in 0 25 dB steps Gain of each of the three amplifier stages is controlled by the processor system by loading latch U2044 with the appropriate 8 bit word from the data bus Digital word 1502B MTDR Service Manual Circuit Descriptions Video Analog to Digital Converter
75. the switch on capacitive feedback is used C2016 This feedback slows the turn on time allowing a capacitive load to be charged without affecting the instrument supply A stabilizing 100 Q resistor R2010 is also located in the feedback loop 5 11 Circuit Descriptions 5 12 Buffers Output Latch Option Port Wiring Configuration There are specified limits to this type of circuitry Load specifications must be followed The arrangement of the 5 VDC switch is similar except that a 10 100 resistive divider is used to ensure the switch has a definite turn on A single FET Q1010 controls the 5 VDC output Data lines to the option port pass through the bus transceiver U2011 Address lines RD and WR are driven by U2012 CS22 from the processor system enables these drivers with RD controlling the transceiver direction U2012 outputs are pulled up by the switched 5 VDC supply via R2015 The data lines are pulled down via 2014 WR is a modified write pulse 200 ns long created to give a rising edge prior to the disabling of the drivers This pulse is created by flip flop U2033A The output latch U1011A is controlled by Ao and Aj with select signal CS10 The output of this latch is optionally used in the interface protocol Two more lines are used in the option port interface IR4 is an interrupt signal that is active low when creating processor interrupts R T TRIG is also avai
76. the instrument on a solid non slip surface with the rear panel facing you 2 EMI shield with the notches in the shield facing the front panel casting Rear flange of EMI shield fits OVER rear panel casting without a gap Front panel casting k lt Side panel N Figure 7 18 Installing Top and Bottom EMI Shields EMI Shields 3 Insert the leading edge of the shield under the lip of the front panel 1502B MTDR Service Manual 7 21 Maintenance 4 Gently push the shield forward inder the lip of the front panel casting as you gently press the shield down until its side flanges mate with the grooves in the side panels At this point the rear flange of the shield should fit over the rear panel casting without a gap 5 Secure the shield to the rear casting with three 4 40 screws at five inch pounds of torque The screw holes in the shield will be offset slightly from those of the casting This assures that the shield will be pulled down tightly when the screws are driven in 6 Turn instrument over and repeat for the other shield Installing the Case Cover Over the Chassis 1 Place the instrument chassis face down on a solid non slip surface so that the rear panel is facing upward Captive mounting screws 4 Case Chassis Front panel casting Figure 7 19 Installing the Case Cover Over the Chassis 2 Reach i
77. to provide coarse 400 ns resolution digital time delay The end of this time delay triggers a fine delay counter which is clocked at 20 MHZ providing 50 ns resolution to the sampler time delay Both the coarse time delay and the fine delay counters are programmed by the processor via the data bus The end of the coarse delay is used to generate a timebase interrupt request to the processor to inform it that a sample is being taken and a timebase update is required for the next sample The output of the fine delay counter is provided to the analog timebase circuits for further delay control to become the sampler trigger The beginning of the coarse delay counter period is detected by a pulse former which generates a driver trigger for the analog timebase 1502B MTDR Service Manual Circuit Descriptions 1502B MTDR Service Manual The analog timebase circuits receive the driver and sampler triggers and provide strobes to the driver sampler The driver trigger is delayed by an analog time delay and amplified by a driver circuit to provide the driver strobe The ramp trigger is used to start a linear voltage ramp generator A voltage comparator detects the time when this ramp reaches the programmed voltage of the timebase DAC digital to analog converter and signals a driver to produce a strobe for the video sampler The timebase DAC 15 programmed by the processor to provide a voltage proportional to the portion of the 50 ns time delay peri
78. 0 322 3097 00 322 3291 00 322 3097 00 322 3356 00 322 3321 00 322 3165 00 322 3261 00 322 3289 00 322 3243 00 322 3314 00 322 3306 00 322 3321 00 322 3385 00 Effective R010100 R010100 Serial No Discontd Qty Name amp Description R020511 R020511 CIRCUIT BD ASSY MAIN W O EPROM Con t RES FXD FILM 2 74M OHM 1 0 125W RES FXD FILM 2 74M OHM 1 0 125W RES FXD FILM 348K OHM 1 0 2W RES NTWK FXD FI 10K OHM 20 9 RES RES FXD FILM 50K OHM 1 0 125W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD METAL FILM 20 0K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES NTWK FXD FI 10K OHM 20 9 RES RES NTWK FXD FI 10K OHM 20 9 RES RES FXD FILM 3 01K OHM 1 0 2W RES FXD FILM 3 01K OHM 1 0 2W RES FXD METAL FILM 11 0K OHM 1 0 2W RES NONWW TRMR 500 OHM 0 5W CERMET RES FXD METAL FILM 274 OHM 196 0 2W RES FXD FILM 243 OHM 1 0 2W RES FXD FILM 243 OHM 1 0 2W RES FXD FILM 200 OHM 1 0 2W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD METAL FILM 12 1K OHM 1 0 2W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD FILM 49 9K OHM 1 0 2W RES FXD FILM 24 9K OHM 1 0 2W RES FXD FILM 511 0HM 1 0 2W RES FXD FILM 5 11K OHM 1 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W RES FXD METAL FILM 3 32K OHM 1 0 2W RES FXD METAL FILM 18 2K OHM 1 0 2W RES FXD METAL FILM 15 0K OHM 1 0 2W RES FXD FILM 24 9K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W 1502B MTDR Service Manual Mfr
79. 0 R1060 TP1020 R1061 TP1021 T Back Side Components 1502B MTDR Service Manual 9 11 Diagrams 4 S R DRIVER SAMPLER CIRCUIT NUMBER TP1030 TP1060 TP1080 TP1081 TP1082 TP1083 TP1084 TP2060 TP3020 U1010 U1050A U1050B U1070A U1070B U2050A U2050B U2070 U3030A U3030B U3070A U3070B SCHEM LOCATION PAGE SCHEM T Back Side Components 9 12 BRD 1502B MTDR Service Manual Diagrams A9 POWER FUSE JACK Option 03 Battery Pack CIRCUIT SCHEM BOARD NUMBER LOCATION LOCATION F9100 D3 PWR SUPP 1502B MTDR Service Manual 9 13 Diagrams 9 14 1502B MTDR Service Manual Replaceable Mechanical Parts This section contains a list of the replaceable mechanical components for the 1502B Use this list to identify and order replacement parts Parts Ordering Information Replacement parts are available through your local Tektronix field office or representative Changes to Tektronix instruments are sometimes made to accommodate improved components as they become available and to give you the benefit of the latest circuit improvements Therefore when ordering parts it is important to include the following information in your order Part number Instrument type or model number Instrument serial number m Instrument modification number if applicable If you order a part that has been replaced with a different or improved part your local Te
80. 00 210 0458 00 200 3497 00 200 3737 00 200 3451 00 200 3451 01 348 0912 00 348 1118 00 348 1118 01 105 0959 00 105 0959 01 407 3675 00 213 0123 00 R010100 R010400 R010100 R010514 R010100 R020514 R010100 R020514 R010100 R010100 R020514 R010100 R010100 R010100 B021135 R010100 B021135 R010100 B021135 B035825 R010100 B025510 B021134 B021134 Serial No Discont d R010399 R010513 020513 020513 020513 020513 020513 R 020513 B021134 B021134 B021134 B035824 B025509 Qty Name amp Description FP N YF e Fr Fr e e wR P N FP Fr YY Ye FRAME AND FRONT PANEL Con t NUT BLOCK 6 32 X 0 438 AL CHROMATE SETSCREW 6 32 X 0 188 HEX CUP PT SETSCREW 6 32 X 0 188 HEX W NYLON RING RETAINER BOWED SFT SCR MACH 4 40 X 0 125 PNH POZ WSHR FLAT 0 15 X 0 375 OD X 0 032 WSHR FLAT 0 119 X 0 375 OD X 0 025 LEVER 3 25L X 0 5W X 0 05 AL LEVER 3 25L X 0 5W X 0 05 AL SHWR SHLDR 0 136 X 0 375 OD X 0 24 NYLON EXTENSION SHAFT 7 59 L X 0 5 AL EXTENSION SHAFT 7 59 L X 0 5 AL SCR MACH 4 40 X 0 188 PNH POZ WHSR FLAT 0 147 X 0 312 OD X 0 028 CHART EXTRUSION ASSEMBLY SCR MACH 8 32 X 0 25 PNH POZ WSHR LOCK 8 INTL 0 02 THK NUT PL ASSEM WA 8 32 X 0 344 ASSY SEE W2010 WIRE ASSEMBLIES COVER PORT 1502B COVER FRONT OPTION PORT COVER PORT INCLUDES COVER PORT 1502B COVER PORT 1502B GASKET
81. 00 322 3289 00 322 3289 00 322 3289 00 Effective R010100 R020410 B021152 R010100 B021152 R010100 R020410 B021152 1502B MTDR Service Manual Serial No Discontd Qty Name amp Description R020409 B021151 B021151 R020409 B021151 CIRCUIT BD ASSY MAIN W O EPROM Con t XSTR SIG BIPOLAR PNP 50V 50MA 40MHZ AMP XSTR SIG FET N CH 3 5V 75MA 90 OHM TO 92 XSTR SIG BIPOLAR NPN 15V 40MA 1 0GHZ AMP XSTR SIG BIPOLAR PNP 15V 30MA 2 0GHZ AMP XSTR NPN SI DUAL XSTR SIG BIPOLAR NPN 45V 30MA 60MHZ AMP XSTR SIG BIPOLAR NPN 45V 30MA 60MHZ AMP XSTR SIG BIPOLAR NPN 15V 40MA 1 0GHZ AMP ZSTR SIG FET N CH 6V 15MA 4 5MS AMP XSTR PNP SI DUA XSTR SIG BIPOLAR PNP 60V 50MA 100MH Z AMP XSTR SIG BIPOLAR PNP 15V 30MA 2 0GHZ AMP XSTR SIG BIPOLAR NPN 15V 40MA 1 0GHZ AMP XSTR SIG BIPOLAR NPN 15V 50MA 600MHZ AMP XSTR SIG BIPOLAR NPN 15V 40MA 1 0GHZ AMP XSTR SIG BIPOLAR NPN 15V 50MA 600MHZ AMP XSTR SIG BIPOLAR PNP 15V 30MA 2 0GHZ AMP XSTR NPN SI DUAL XSTR SIG BIPOLAR NPN 45V 30MA 60MHZ AMP XSTR SIG BIPOLAR NPN 45V 30MA 60MHZ AMP XSTR SIG BIPOLAR PNP 15V 30MA 2 0GHZ AMP RES FXD METAL FILM 475 OHM 196 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 20 0K OHM 1 0 2W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W RES FXD MET
82. 000 Ft 022225 move cursor to reference and Press STORE Figure 1 23 Cursor Moved to End of Three Foot Lead in Cable 3 Push STORE 4 Turnthe NOISE FILTER control to 1 avg The instrument is now in HORZ SET REF or delta mode The distance window should now read 0 00 ft As the cursor is scrolled down the cable the distance reading will now be from the new zero reference point LANE MEE F Figure 1 24 Cursor Moved to End of Three Foot Lead in Cable NOTE Vp changes will affect where the reference is set on the cable Be sure to set the Vp first then set the delta to the desired location 5 Toexit HORZ SET REF use the following procedure a Turn the NOISE FILTER control to HORZ SET REF b Turn DIST DIV to 1 ft div If the distance reading is extremely high you might want to use a higher setting initially then turn to 1 ft div for the next adjustment c Turn the df POSITION control until the distance window reads 0 00 ft 1502B MTDR Service Manual Operating Instructions Using Vertical Set Reference 1502B MTDR Service Manual ac move cursor to reference and Press STORE U U Figure 1 25 Moved 0 00 ft Push STORE e Turn NOISE FILTER to desired setting VERT SET REF works similar to HORZ SET REF except that it sets a reference for gain pulse height instead of distance This
83. 003D 5033R 10030 120 0582 00 8 33 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A4 A4TP1020 A4TP1021 A4TP1030 A4TP1060 A4TP 1080 A4TP 1081 4 1082 A4TP 1083 4 1084 4 2060 4 3020 A4U1010 A4U1050 A4U1070 A4U2050 A4U2070 A4U3030 A4U3070 8 34 Tektronix Part Number 670 9291 XX 214 0579 00 214 0579 00 214 0579 00 214 0579 00 214 0579 00 214 0579 00 214 0579 00 214 0579 00 214 0579 00 214 0579 00 214 0579 00 119 2369 01 156 0853 00 156 0853 00 156 1291 00 156 1490 00 156 2761 00 156 0853 00 Serial No Effective B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 B010100 Serial No Discontd Qty Name amp Description 8037261 8037261 8037261 8037261 8037261 8037261 8037261 8037261 8037261 8037261 8037261 CKT BD ASSY S R DRIVER SANPLER Con t TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L HYBRID TDR FRONT END IC LINEAR BIPOLAR OP AMP DUAL IC LINEAR BIPOLAR OP AMP DUAL IC
84. 01 57668 57668 57668 57668 57668 57668 57668 91637 57668 57668 57668 57668 57668 57668 57668 57668 57668 91637 57668 Mfr Part Number CCF501G 200R OF CCF50 2F619R OF CRB20 FXE 12K1 CCF50G5111FT CRB20 100K CCF50 2 640201F CCF501G 200R OF CRB20 FXE 23K7 CCF50G5111FT CRB20 FXE 8K25 CRB20 FXE243E CRB20 FXE 249E 5043ED255R OF CRB20 FXE 261 CRB20 FXE 267E CRB20 FXE 274E CRB20 FXE 287E CRB20 FXE10E0 BZE127K CRB20 FXE CCF502631601FT CRB20 FXE 499E CRB20 FXE10E0 CRB20 FXE10E0 CRB20 FXE 49E9 CRB20 FXE 8K06 CRB20 FXE 2K00 CRB20 FXE 100E CRB20 FXE 49E9 CRB20 FXE 806E CCF50 2F39200F CRB20 FXE 49E9 8 15 Replaceable Electrical Parts Replaceable Parts List Cont Assy Tektronix Serial No Serial No Mfr Number Part Number Effective Discontd Qty amp Description Code Mfr Part Number MA 670 9285 CIRCUIT ASSY MAIN W O EPROM Con t AlA1R6031 322 3262 00 RES FXD FILM 5 23K OHM 1 0 2W 57668 CRB20FXE 5K23 AlA1R6032 322 3251 00 RES FXD FILM 4 02K OHM 196 0 2W 57668 CRB20FXE 4K02 AlA1R6033 322 3139 00 RES FXD METAL FILM 274 OHM 196 0 2W 57668 CRB20FXE 274E 1 1 6040 322 3222 00 RES FXD METAL FILM 2 00K OHM 1 0 2W 57668 CRB20FXE 2K00 1 1 6041 321 0960 07 RES FXD FILM 513 OHM 0 1 0 125W 01121 ADVISE 1 1 6042 322 3175 00 RES FXD FILM 649 0HM 1 0 2W 57668 CRB20FXE 649E A1A1R6043 322 3185 00 RES FXD METAL FILM 825 OHM 1 0 2W 57668 CRB20FXE 825E 1 1 60
85. 026 00 IC DIGITAL HCMOS GATE QUAD 2 INPUT NOR 04713 MC74HC02AN A1A1U3021 156 3107 00 IC DIGITAL HCMOS FLIP FLOP OCTAL D TYPE 01295 SN74HC374N A1A1U3022 156 2421 00 IC DIGITAL HCMOS FLIP FLOP QUAD D TYPE 04713 MC74HC175N A1A1U3023 156 0927 00 IC LINEAR DIGITAL TO ANALOG CONVERTER 04713 MC3410CL A1A1U3040 156 1173 00 IC LINEAR BIPOLAR VOLT REF POS 2 5V 1 096 04713 14030 A1A1U3041 156 0854 00 IC LINEAR BIPOLAR OP AMP 24355 OP08FP OR PM308 026P A1A1U3042 156 1114 00 IC LINEAR MOS FET INP COS MOS OUT OP AMP 34371 160 A1A1U4020 156 3151 00 IC INTFC CMOS D A CONVERTER 24355 7534 A1A1U4021 156 1699 00 IC LINEAR DUAL BI FET OPNL OFFSET 01295 TL288CP 1 104040 156 0513 00 IC MISC CMOS ANALOG MUX 8 CHANNEL 04713 14051 AlA1U5010 156 0854 00 IC LINEAR BIPOLAR OP AMP 24355 OP08FP OR PM308 026P A1A1U5020 156 1156 00 IC LINEAR BIFET OP AMP LF 356N DIP 08 3 04713 LF356N A1A1U5040 156 1114 00 IC LINEAR MOS FET INP COS MOS OUT OP AMP 34371 160 A1A1U6040 156 0513 00 IC MISC CMOS ANALOG MUX 8 CHANNEL 04713 14051 A1A1U7010 156 2763 00 IC DIGITAL HCMOS FLIP FLOP DUAL J K 04713 MC74HC113N A1A1U7040 156 1114 00 LINEAR MOS FET INP COS MOS OUT OP AMP 34371 160 A1A1U8010 156 1707 00 IC DIGITAL FTTL GATE QUAD 2 INPUT 04713 MC74F00 A1A1U8040 156 0513 00 IC MISC CMOS ANALOG MUX 8 CHANNEL 04713 MC14051BCP A1A1U8041 156 1114 00 IC LINEAR MOS FET INP COS MOS OUT OP AMP 343
86. 0296 00 322 3293 00 321 0197 00 322 3191 00 322 3235 00 322 3231 00 321 0302 00 322 3193 00 317 0027 00 321 0245 00 522 3231 00 322 3300 02 321 0001 00 308 0739 00 322 3385 00 322 3357 00 322 3289 00 322 3097 00 322 3385 00 322 3385 00 321 0253 00 322 3222 00 322 3193 00 322 3261 00 322 3239 00 322 3239 00 322 3289 00 308 0839 00 322 3326 00 317 0027 00 308 0767 00 Serial No Effective R010100 R 020399 R010100 R 020399 R010100 R010141 R010100 R010141 Serial No Discontd Qty Name amp Description R 020398 R020398 R010140 R010140 CIRCUIT BD ASSY POWER SUPPLY Con t RES FXD FILM 11 8K OHM 1 0 125W RES FXD FILM 11K OHM 1 0 2W RES FXD FILM 1 10K OHM 1 0 125W RES FXD FILM 953 OHM 1 0 2W RES FXD METAL FILM 2 74K OHM 1 0 2W RES FXD FILM 2 49K OHM 1 0 2W RES FXD FILM 13 7K OHM 1 0 125W RES FXD METAL FILM 1K OHM 196 0 2W RES FXD CMPSN 2 7 595 0 125 RES FXD FILM 3 48K OHM 1 0 125W RES FXD FILM 4 64K OHM 1 0 2W RES FXD FILM 13K OHM 1 0 2W RES FXD FILM 10 OHM 1 0 125W RES FXD WW 4 OHM 1 3W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD FILM 51 1K OHM 1 0 2W RES FXD METAL FILM 10K OHM 1 0 2W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD FILM 4 22K OHM 1 0 125W RES FXD METAL FILM 2K OHM 196 0 2W RES FXD METAL FILM 1K OHM 196 0 2W RES FXD FILM 5 11K OHM 1 0 2W RES FXD FILM 3 01K OHM 1 0 2W R
87. 05C105MAATRSTDII 1990106 0025 1 1990106 0025 1 SR305E105ZAA SR305E105ZAA SR305E105ZAA SME35VB101M8X11FT SR305E105ZAA SME35VB101M8X11FT 8 25 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A3M A3A1C2011 A3A1C2012 A3A1C2013 A3A1C2020 A3A1C2021 A3A1C2022 A3A1C2023 A3A1C2024 1 2025 1 2030 1 2031 A3A1CR1010 A3A1CR1011 A3A1CR1030 A3A1CR1031 A3A1CR1032 A3A1CR1033 A3A1CR1034 A3A1CR2010 A3A1CR2011 A3A1CR2012 A3A1CR2013 A3A1CR2014 A3A1CR2015 A3A1CR 2016 A3A1CR 2020 A3A1CR 2021 A3A1CR 2030 A3A1CR2031 8 26 Tektronix Part Number 670 9286 XX 290 0517 00 290 0973 01 283 0198 00 283 0051 00 290 0745 02 283 0010 00 283 0220 02 281 0925 01 290 0846 00 281 0925 01 283 0059 02 152 0406 00 152 0322 00 152 0582 00 152 0582 00 152 0581 00 152 0581 00 152 0779 00 152 0601 00 152 1165 00 152 0582 00 152 0322 00 152 0322 00 152 0601 00 152 0836 00 152 0141 02 152 0322 00 152 0601 00 152 0333 00 152 0333 00 Effective R020399 R010100 R010141 Serial No Discontd Qty Name amp Description R010140 CIRCUIT BD ASSY POWER SUPPLY Con t CAP FXD ELCTLT 6 8UF 20 35V CAP FXD ELCTLT 100UF 20 25VDC AL CAP FXD CER DI 0 22UF 20 50V CAP FXD CER DI 0 0033UF 5 100V CAP FXD ELCTLT 22UF 50 10 25V AL CAP FXD CER DI 0 05UF 80 20 50V CAP FXD CER DI 0 01UF 20 50V CAP FXD CER DI 0 22UF 20 5
88. 0V CAP FXD ELCTLT 47UF 75 20 35V AL CAP FXD CER 01 0 220 20 50 CAP FXD CER DI 1UF 20 50V DIODE RECT BRIDGE 250V 3A 1 2VF DIODE DVC DI SCHOTTKY 51 15 1 2 DIODE RECT SCHTKY 20V 3A 475VF 80A DIODE RECT SCHTKY 20V 3A 475VF 80A DIODE RECT SCHTKY 20V 1A 450VF 25A DIODE RECT SCHTKY 20V 1A 450VF 25A DIODE RECT FAST RCVRY 200V DIODE RECT ULTRA FAST 150V 25N5 35A DIODE RECT 600V 4A 50NS DIODE RECT S CHTKY 20V 3A 475VF 80A DIODE DVC DI SCHOTTKY SI 15V 1 2PF DIODE DVC DI SCHOTTKY SI 15V 1 2PF DIODE RECT ULTRA FAST 150V 25N5 35A DIODE DVC DI RECT SI 1A 40V 115819 DIODE SIG ULTRA FAST 40V 150MA 4NS 2PF DIODE DVC DI S CHOTTKY SI 15V 1 2PF DIODE RECT ULTRA FAST 150V 25N5 35A DIODE DVC DI SW S1 55V 200MA DIODE DVC DI SW S1 55V 200MA Mfr Code 24165 1W344 04222 04222 55680 04222 04222 31433 0 9R5 31433 04222 14936 50434 04713 04713 14936 14936 80009 04713 04713 04713 50434 50434 04713 80009 14433 50434 04713 12969 12969 Mfr Part Number 199D685X0035DA1 SME35VB101M8X11FT SR305C224MAA SR301A332 AA UVX2A220MPA SR305E503ZAA AR205C103MAATRSTDII 114 224 5 5 CEUSM1J470 C114C224M5Y5CA SR305C105MAATRSTDII GBPC604 5082 2672 1N5820 1N5820 SB120 5 SB120 5 152 0779 00 MUR115 MUR460RL 1N5820 5082 2672 5082 2672 MUR115 152 0836 00 1N4152 5082 2672 MUR115 NDP261 NDP261 1502B MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont
89. 0V 99 0 L 29870 ORD BY DESCR OPTION A4 NORTH AMERICA ONLY 41 161 0154 00 1 CA ASSY PWR 3 0 75mm SQ 240V 6A 2 5ML 53109 12 H05VVF3G 00 5 OPTION A5 SWITZERLAND ONLY 42 161 0228 00 1 CA ASSY PWR 3 18 AWG 98 0 L STANDARD CABLE 70903 FH49061 ALL OF THE CABLES LISTED ARE SAFETY CONTROLLED 10 6 1502 Service Manual Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont Fig amp Index Tektronix Part Serial No Number Number Effective FIG 10 1 016 0814 00 070 6266 XX 1502B MTDR Service Manual Serial No Discontd Qty amp Description CABINET Con t POUCH ACCESS 11 5 X 9 5 X 1 75 H VINYL MANUAL TECH OPERATORS 1502B TDR Mfr Code Mfr Part Number 0JRZ2 016 0814 00 80009 070 6266 10 7 Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont Fig amp Index Number FIG 10 2 12 13 14 15 16 10 8 Tektronix Part Number 366 2097 00 366 2104 00 366 2098 00 213 0153 00 131 4178 00 650 3697 00 210 0583 00 210 0940 00 354 0581 00 348 1145 00 348 1145 01 366 0655 05 366 0655 01 366 0655 02 366 0655 03 366 0655 04 334 6664 00 334 6664 01 Serial No Effective B021135 B035825 R010100 B025496 Serial No Discont d B035824 B025495 Qty Name amp Description e eae na SR PR e ea FRAME AND FRONT PANEL SHELL KNOB DOVE GRAY 0 060 X 0 375 KNO
90. 1 283 0177 00 281 0925 01 283 0111 04 281 0813 00 281 0925 01 283 0359 01 283 0177 00 283 0059 02 283 0330 00 281 0925 01 281 0925 01 290 0748 00 281 0925 01 283 0010 00 281 0798 00 283 0330 00 281 0925 01 283 0348 00 283 0156 00 283 0111 04 281 0813 00 283 0359 01 281 0925 01 281 0813 00 281 0925 01 281 0813 00 281 0925 01 281 0925 01 290 0748 00 283 0359 01 283 0359 01 1502B MTDR Service Manual Discontd Qty Name amp Description CIRCUIT BD ASSY MAIN W O EPROM Con t CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 1UF 80 20 25V CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 0 1UF 2096 50V SQ CAP DI MLC 0 04UF 20 50V CAP DI MLC 0 22UF 2096 50V Z25U CAP FXD CER 01 1000 5 200 SQ CAP FXD CER DI 1UF 80 20 25V CAP DI 1UF 2096 50V CAP FXD CER 01 100 5 50 SQ CAP DI MLC 0 22UF 2096 50V Z5U CAP DI MLC 0 22UF 2096 50V Z5U CAP FXD ELCTLT 10UF 50 20 25W VDC CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 0 05UF 80 20 50V SQ CAP FXD CER DI 51PF 1 100V TUBULAR CAP FXD CER DI 100PF 5 50V SQ CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 0 5PF 0 1PF 100V CAP FXD CER 01 1000 80 20 200 SQ CAP FXD CER DI 0 1UF 2096 50V SQ CAP FXD CER DI MLC 0 047UF 2096 50V CAP FXD CER DI 1000P F 596 200V SQ CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 04UF 20 50V
91. 11 A4C2012 A4C2020 A4C2021 A4C2022 A4C2023 A4C2024 A4C2025 A4C2026 A4C2030 A4C2031 A4C2040 A4C2041 A4C2042 A4C2050 A4C2051 8 30 Tektronix Part Number 670 9291 XX 281 0775 00 281 0775 00 290 0723 00 281 0775 00 281 0775 00 290 0804 01 281 0765 00 281 0775 00 281 0775 00 281 0775 00 281 0775 00 290 0536 04 283 5002 00 283 0359 01 283 5002 00 283 0359 01 290 0523 00 290 0523 00 290 0523 00 290 0523 00 290 0523 00 283 5002 00 283 0359 01 283 5002 00 283 0359 01 281 0861 00 283 0193 00 281 0775 00 281 0775 00 281 0861 00 281 0775 00 290 0522 01 Serial No Effective B021135 8036427 8021135 8036427 8021135 8036427 8021135 8036427 Discontd Qty Name amp Description B036426 B036426 B036426 B036426 CKT BD ASSY S R DRIVER SAMPLER CAP FXD CER DI 0 1UF 20 50V CAP FXD CER DI 0 1UF 20 50V CAP FXD ELCTLT 150UF 20 6V CAP FXD CER DI 0 1UF 20 50V CAP FXD CER DI 0 1UF 20 50V CAP FXD ELCTLT 10UF 2090 25 AL CAP FXD CER 01 100 5 100 CAP FXD CER DI 0 1UF 20 50V CAP FXD CER DI 0 1UF 20 50V CAP FXD CER DI 0 1UF 20 50V CAP FXD CER DI 0 1UF 20 50V CAP FXD ELCTLT 10UF 2090 25V CAP FXD CER DI 1000PF 10 50V CAP FXD CER DI 1000PF 5 200V CAP FXD CER DI 1000PF 10 50V CAP FXD CER DI 1000PF 5 200V CAP FXD ELCTLT 2 2UF 20 20V CAP FXD ELCTLT 2 2UF 20 20V CAP FXD ELCTLT 2 2UF 20 20V CAP FXD ELCTLT 2
92. 16 Figure 6 17 Figure 6 18 Figure 6 19 Figure 6 20 Figure 6 21 Figure 6 22 Figure 6 23 Figure 6 24 Figure 6 25 Figure 6 26 Figure 6 27 Figure 6 28 Figure 6 29 Figure 6 30 Figure 6 31 Figure 6 32 Figure 6 33 Figure 6 34 Figure 6 35 Figure 6 36 Shift Register CPU and Display Memory Interface Typical Start Up Display Waveform on the Display Setup Menu Main Menu Diagnostics Menu Front Panel Diagnostic Display Front Panel Diagnostic Display Front Panel Diagnostic Display Front Panel Diagnostic Display Waveform on the Display with No Cable Attached Display with 3 ft Cable and Stored Waveform Cursor on Rising Edge of Pulse Cursor at 0 000 ft Cursor on Rising Edge of Pulse Flatline Display to gt 2 000 ft Incident Pulse at 2 000 ft Incident Pulse at 2 000 ft with 3 ft Cable Connected Incident Pulse at 2 000 ft with Max Hold Waveform at Top of the Display Waveform at Bottom of the Display Waveform at Centered Cursor Moved to 100 000 ft Noise with Gain at 5 00 mp Noise Diagnostic Display Service Diagnostic Menu Service Diagnostic Menu Service Diagnostic Menu Waveform with Cursor at 2 000 ft Waveform at 50 mp div Waveform at 5 mp div Incident Pulse at Center of Display Incident Pulse Centered Vertical Increased
93. 181 00 283 0359 01 281 0925 01 283 0359 01 285 1241 00 281 0925 01 281 0813 00 290 0748 00 283 0330 00 283 0359 01 283 0359 01 281 0925 01 283 0359 01 283 0177 00 283 0177 00 281 0813 00 281 0813 00 281 0798 00 283 0330 00 283 0330 00 281 0925 01 281 0925 01 Discontd Qty Name amp Description CIRCUIT BD ASSY MAIN W O EPROM Con t CAP DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 22UF 20 50V Z5U DI 1 8PF 0 1 100V SQ DI 51PF 5 200V SQ DI 0 1UF 1096 100V SQ 01 220 10 200 SQ DI 100PF 5 50V SQ DI 1000PF 5 200V SQ DI MLC 0 22UF 20 50V Z5U DI MLC 0 22UF 20 50V Z5U DI 1 8PF 4 0 196 100V SQ DI 1000PF 5 200V SQ DI MLC 0 22UF 20 50V Z5U DI 1000PF 5 200V SQ CAP FXD PLASTIC 0 22UF 10 100V CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI MLC 0 04UF 20 50V CAP FXD ELCTLT 10UF 50 20 25W VDC CAP FXD CER DI 100PF 5 50V SQ CAP FXD CER DI 1000PF 5 200V SQ CAP FXD CER DI 1000PF 5 200V SQ CAP FXD CER DI MLC 0 22UF 20 50V Z5U CAP FXD CER DI 1000PF 5 200V SQ CAP FXD CER DI 1UF 80 20 25V CAP FXD CER DI 1UF 80 20 25V CAP FXD CER DI MLC 0 04UF 20 50V CAP FXD CER DI MLC 0 04UF 20 50V CAP FXD CER DI 51PF 1 100V TUBULAR MI
94. 2 41 X 3 16 X 0 062 REINF SI W PSA GASKET COND ELASTOMER W AL GASKET OPTION PORT COVER 0 062 THK LCH OPT PORT COVER STEEL ZINC PLATE LCH OPT PORT COVER STEEL ZINC PLATE FRAME OPTION PORT COVER SCR TPG TF 6 32 X 0 375 FLH100 DEG POZ Mfr Code 5Y 400 80009 80009 19136 0 01 12327 12327 80009 80009 80009 80009 80009 93907 12327 5Y 400 80009 OKBO1 OKBO1 80009 0 260 80009 80009 2K262 0 25 0 25 72794 72794 0 260 72228 Mfr Part Number 220 0961 00 213 0004 00 213 0966 00 5131 12 CD ORD BY DESCR ORD BY DESCR ORD BY DESCR 105 0954 00 105 0954 01 210 1421 00 384 1674 00 384 1674 01 ORD BY DESCR ORD BY DESCR 650 3699 00 212 0001 00 ORD BY DESCR ORD BY DESCR 200 3497 00 200 3731 00 200 3451 00 200 3451 01 348 0912 00 348 1118 00 348 1118 01 DZUSDP1095MOD DZUSDP1095MOD 407 3675 00 ORD BY DESCR 1502B MTDR Service Manual Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont Fig amp Index Number FIG 10 2 sol 592 492 54 359 56 zer 58 59 60 61 62 63 64 65 66 67 68 69 70 s l 12 13 14 RIS 16 i 1502B MTDR Service Manual Tektronix Part Number 200 3123 00 348 0974 00 211 0661 00 131 0391 00 131 3360 00 407 1694 00 211 0513 00 210 0055 00 256 0570 00 129 0562 00 441 1683 00 211 0198 00 211 0661 00 210 1307 00 211 0661 00 211 0007 00 210 1307 00
95. 23 466 ceased oad 56 5 25 Display Module 55552 2222 6 ama ud Pont 5 29 1502 MTDR Service Manual i Contents an 6 1 lineo aro gate ct 6 1 Calibration Performance Check 6 1 Display Module Ce Kc oua u kv nw tee meres db e wa aae ads 6 2 ne 6 4 Horizontal Scale Timebase Check 6 7 Zero DI sa esu a 6 10 Vertical Position Offset Check 6 12 No 6 13 Check 6 15 ISSUE 6 16 J AMURONICHOGE 6 16 as 6 17 RISE 6 19 Vitter ENT 6 21 Option 03 Battery Pack Check 6 23 Option 04 07 YT 1 YT 1S Chart Recorder Check 6 23 Option 05 Metric Default Check aos u Staa od 6 23 Adjustment Procedures 6 24 bo ccc M P 6 25 Power Supply Checks and Adjustments 6 25 Main Board 712 VDC Check and Adjust 6 29 Tbedance C uu i soe oon ee kes QUEUE E hup OU a BOR E s cg e 6 34 LCD Check and Adjustment
96. 23 156 2026 00 IC DIGITAL HCMOS GATE QUAD 2 INPUT NOR 04713 MC74HC02AN A2U3025 156 2758 00 IC DIGITAL HCMOS MUX ENCODER DUAL 0JRO4 TC74HC253AP A2U3031 156 2758 00 IC DIGITAL HCMOS MUX ENCODER DUAL 0JRO4 TC74HC253AP 8 24 1502 MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A3C102 A3C201 A3F101 A3F101 A3FL1 A3L201 A3R101 A35201 A3T201 A3M A3A1C1010 A3A1C1011 A3A1C1012 1 1013 1 1014 1 1015 1 1016 1 1030 1 1031 1 1032 1 1033 1 1034 1 1035 1 1036 1 1037 1 1038 1 2010 Tektronix Part Number 620 0477 XX 283 0024 00 283 0167 00 159 0029 01 159 0054 00 119 1957 00 119 3488 00 120 1458 00 307 0449 00 260 2372 00 120 1607 00 120 1922 00 670 9286 290 0997 00 283 0220 02 283 0359 01 281 0925 01 283 0359 01 283 0359 01 283 0107 00 283 0059 02 283 0059 02 290 0536 04 290 0536 04 283 0177 00 283 0177 00 283 0177 00 290 0973 01 283 0177 00 290 0973 01 Serial No Effective B025000 R010100 B025000 B025000 B010100 B037303 1502B MTDR Service Manual Serial No Discontd Qty Name amp Description B037302 B024999 B037302 B037302 POWER SUPPLY ASSEMBLY CHASSIS MOUNTED ELECTRICAL PARTS DI 0 1UF 80 20 50V DI 0 1UF 10 100V FUSE CARTRID
97. 2UF 20 20V CAP FXD ELCTLT 2 2UF 20 20V CAP FXD CER DI 1000PF 10 50V CAP FXD CER DI 1000PF 5 200V CAP FXD CER DI 1000PF 10 50V CAP FXD CER DI 1000PF 5 200V CAP FXD CER DI 270PF 5 50V CAP FXD CER 510 2 100 CAP FXD CER DI 0 1UF 20 50V CAP FXD CER DI 0 1UF 20 50V CAP FXD CER DI 270PF 5 50V CAP FXD CER DI 0 1UF 20 50V CAP FXD ELCTLT 1UF 20 50V Mfr Code 04222 04222 24165 04222 04222 OHIN5 04222 04222 04222 04222 04222 24165 04222 31433 04222 31433 24165 24165 24165 24165 24165 04222 31433 04222 31433 04222 04222 04222 04222 04222 04222 31433 1502B MTDR Service Manual Mfr Part Number SA105E104MAA SA105E104MAA 196D157X0006PE3 SA105E104MAA SA105E104MAA CEUSM1E100T12 SA102A101JAA SA105E104MAA SA105E104MAA SA105E104MAA SA105E104MAA 199D106X0025CA1 W1206C102K3B04 C322C102J2G5CA W1206C102K3B04 C322C102J2G5CA 196D225X0020HA1 196D225X0020HA1 196D225X0020HA1 196D225X0020HA1 196D225X0020HA1 W1206C102K3B04 C322C102J2G5CA W1206C102K3B04 C322C102J2G5CA SA101A271JAA SR201A511GAA SA105E104MAA SA105E104MAA SA101A271JAA SA105E104MAA T355B105M050A5 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A4 A4C2052 A4C2053 A4C2072 4 2080 4 2081 A4C2082 A4C2083 A4C3010 A4C3011 A4C3020 A4C3030 A4C3060 A4C3061 A4C3062 4 3063 4 3064 A4C3065 A4C3070 A4C3080 A4CR1030 A4CR1031 A4CR1032 A4CR1040 A4CR 2050
98. 3 CR2014 CR2015 CR2016 CR2020 CR2021 CR2030 CR2031 J1010 J1030 J2010 L1010 L2020 Q1010 Q1011 Q1012 Q2010 Q2011 Q2012 Q2020 Q2021 Q2022 Q2030 Q2031 R1010 R1011 R1012 R1013 R1014 R1015 R1016 R1017 R1018 R1020 R1021 R1022 R1023 R1024 R1025 R1026 R1030 R2010 R2011 R2012 R2013 R2014 R2015 R2016 R2017 R2018 R2020 R2021 R2022 R2023 R2024 R2025 R2026 R2027 R2030 R2031 R2032 52010 T1030 T1031 TP1010 9 9 Diagrams 1 POWER SUPPLY CIRCUIT NUMBER TP1020 TP2010 TP2030 U1010 U1011 U1020A U1020B U1021A U1021B U1022 U1023 U1024B U2010 U2030A U2030B U2030C U2030D U2030E VR1012 SCHEM PAGE LOCATION SCHEM BRD T Back Side Components 9 10 1502B MTDR Service Manual Diagrams 4 S R DRIVER SAMPLER CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD 3061 R1062 C3062 R1063 C3063 R1064 C3064 R1065 C3065 R1066 C3070 R1070 C3080 R1071 R1072 CR1030 R2030 CR1031 R2031 CR1032 R2040 CR1040 R2041 CR2050 CR2051 R2042 R2043 CR2052 R2045 CR3020 R2046 CR3021 R2047 R2048 J3040 R2049 L2080 R2050 L2081 R2051 R2052 Q1030 R2053 Q1060 R2054 Q2030 Q2040 R3020 Q2050 R3021 R3032 R1010 R3033 R1020 R3040 R1030 R3050 R1031 R1040 R3051 R1041 R3061 R3062 R1042 R3070 R1050 R3071 R1051 R3080 R1052 R1053 T102
99. 3 is an eight channel analog to digital converter It converts the voltages on the wipers of the resistive shaft encoders to a digital value depending on the position of the encoders It also converts the voltage on the display thermistor TsgNsp and the chart recorder thermistor divider circuits into digital values representing the corresponding temperatures The temperature data is used by the processor to compensate the LCD drive voltage and chart recorder print parameters for variations in temperature The control signal TRIG ADC is used to start a conversion ADC RD reads the value and Ao and A select one of the eight channels for conversion Control signal EOC notifies the processor of a conversion completion via the IR3 line 9 27 Circuit Descriptions Electroluminescent Backlight Switch and Power Supply Display Heater Circuitry 5 28 Display Temperature Compensation The EL electroluminescent backlight is switched by software Control signal LIGHTCS with RD or WR sets or resets respectively NOR latch U3020 The output of the latch is applied to side of comparator U2020B the side is held at 2 5 VDC When the output of the latch is high the comparator output is 16 VDC which turns off the gate of P channel FET Q1030 turning off power to the EL power supply PS2030 When the output is low the comparator output is OV which turns on the FET turning on the power to the EL power supply R1031
100. 32 and gates U1030 and U1031D Six interrupt requests signals are logically OR d by 01030 then inverted by U1031D and applied to the microprocessor interrupt request input Five of the interrupts are received from the video ADC the digital timebase a real time counter the front panel control ADC and from the Option Port connector The sixth interrupt input is unused The six interrupt requests and two power status signals are connected to pull up resistors R1033 and the inputs of buffer U1032 When the microprocessor responds to an interrupt request it selects U1032 allowing the eight inputs to that device to be placed on the data bus for reading The processor system outputs six control signals to the Driver Sampler module These signals are loaded from the data bus into latch U3010 by a select signal from the address decoder These signals are used by the 1502B Driver Sampler and the Option 06 adapter if equipped The option port interface consists of the following m Supply Controller m Buffers Output Latch 1502B MTDR Service Manual Circuit Descriptions Supply Control 1502B MTDR Service Manual The option port interface provides the connection between the processor system and external options This port has a unique protocol that must be followed for proper and safe operation Further information can be obtained by contacting your Tektronix customer service representative A block diagram of the option port interfa
101. 351 0755 00 211 0007 00 211 0105 00 211 0661 00 211 0198 00 210 0005 00 211 0661 00 131 3361 00 131 3181 00 131 3359 00 136 0755 00 8010100 8010100 8010100 8010100 8010100 amp 010100 8020820 010100 R010100 B020820 B037618 Serial No Discont d B037562 B037562 B037562 B037562 B037562 B020819 B020819 B020819 Qty Name amp Description Lr e FP WO e YP e Fr e e e A e e Lr N N N N e Lr P e N FRAME AND FRONT PANEL Con t COVER MODULE FRONT SHLD GSKT ELEC FRONT COVER SCR ASSEM WSHR 4 40 X 0 25 PNH POZ CKT BD ASSY SEE A4 REPL CONN RF J ACK SMB 50 OHM 1503B 3C ONLY CONN HDR PCB MALE SHRD ASIDES BRACKET RTNG AL SCR MACH 6 32 X 0 625 WSHR LOCK 6 SPLIT 0 031 DEHYDRATING AGENT SILICA GEL POST RETAINER 0 892 L X 0 375 HEX AL CHASSIS FRONT AL SCR MACH 4 40 X 438 PNH POZ SCR ASSEM WSHR 4 40 X 0 25 PNH POZ WSHR LOCK 0 115 ID SPLIT SCR ASSEM WSHR 4 40 X 0 25 PNH POZ SCR MACH 4 40 X 0 188 PNH POZ WSHR LOCK 0 115 ID SPLIT GUIDE CKT BD POLYCARBONATE 2 5 L CA ASSY SEE WIRE ASSEMBLIES NUT PL ASSEM W 4 40 X 0 25 1503B 3C ONLY POWER SUPPLY ASSY SEE A3REPL SCR MACH 4 40 X 0 188 PNH POZ SCR MACH 4 40 X 0 188 FLH POZ SCR ASSEM WSHR 4 40 X 0 25 PNH POZ SCR MACH 4 40 X 0 438 2 WSHR LOCK 6 EXT 0 02 THK STL CD PL CKT BD ASSY SEE A1 REPL SCR ASSEM WSHR 4 40 X 0 25 PNH
102. 4 00 152 0217 00 Effective B010100 B010100 B010100 B010100 R010141 1502B MTDR Service Manual Serial No Discontd Qty Name amp Description 037261 037261 037261 037261 CIRCUIT BD ASSY POWER SUPPLY Con t SWITCH TOGGLE SPDT 3A 250VAC XFMR PWR SW 40KHZ IN 16 2V OUT 4 15V XFMR TOROID 5 TURNS BIFILAR 3T2 TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L TERM TEST POINT 0 052 ID 0 169 H 0 465 L IC LINEAR REGULATOR PULSE WIDTH IC LINEAR BIPOLAR VOLT REF P0S 2 5V 1 0 LINEAR BIPOLAR COMPARATOR DUAL LINEAR BIPOLAR COMPARATOR DUAL IC LINEAR BIPOLAR VOLT REF P0S 2 5V 1 0 IC LINEAR REGULATOR PULSE WIDTH IC DIGITAL CMOS FLIP FLOP DUAL D TYPE IC LINEAR BIPOLAR VOLT REG POS ADJ IC DIGITAL CMOS BUFFER DRIVER HEX INV DIODE ZENER 8 2V 596 0 4W Mfr Code 80009 0 R03 0 R03 10392 10392 10392 10392 34333 04713 04713 04713 04713 34333 04713 04713 04713 14552 Mfr Part Number 260 2370 00 120 1608 00 120 0487 00 7 16150 8 7 16150 8 7 16150 8 7 16150 8 SG3524N MC1403U LM393N LM393N MC1403U SG3524N MC14013BCP LM317T MC14049UBCP TD3810979 8 29 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A4 A4C1010 A4C1011 A4C1020 A4C1030 A4C1040 A4C1041 A4C1050 A4C1060 A4C1061 A4C1070 A4C1071 A4C2010 A4C20
103. 4 amp 4 o Temperature Vp 0 30 Reading lt I gt Control 142 0 A MU PR 1l 181 ew G LL LLL Vertical Scale _ 800000 190 24 EEE 0000000000000000000000000000 Figure 6 9 Front Panel Diagnostic Display 2 Press MENU repeatedly until the Instrument returns to normal operation If any of the controls or functions are defective or indicate erratic response the function affected by that control could be in error The defective control should be replaced See the Maintenance chapter of this manual Horizontal Scale Timebase Check 1502B MTDR Service Manual If the instrument fails this check it must be repaired before any distance measurements are made with it 1 Setthe front panel controls CABLE No connection see text NOISE FILTER avg VERT SCALE 500 mp DIST DIV ft div Vp 66 6 7 Calibration 6 8 2 Turn on the Instrument The display should look very similar to Figure 6 10 Figure 6 10 Waveform the Display with Cable Attached Press STORE Connect the 3 ft precision test cable to the front panel CABLE connector Press VIEW DIFF P p Rotate NOISE FILTER to HORZ SET REF The display should look like Figure 6 11 a 1 0 0008 move cursor to reference and Press STORE Figure 6 11 Display with 3 ft Cable and Stored Waveform 7 Using the q gt POSITION control set the curs
104. 44 322 3194 00 RES FXD FILM 1 02K OHM 1 0 2W 91637 CCF50 2610200F 1 1 6045 322 3204 00 RES FXD FILM 1 30K OHM 1 0 2W 57668 20 1K30 A1A1R6046 322 3213 00 RES FXD FILM 1 62K OHM 1 0 2W 57668 CRB20FXE 1K62 1 1 6047 322 3223 00 RES FXD FILM 2 05K OHM 1 0 2W 57668 CRB20FXE 2K05 A1A1R7010 322 3114 00 RES FXD METAL FILM 150 OHM 1 0 2W 57668 CRB20 FX150E AlA1R7011 322 3097 00 RES FXD METAL FILM 100 OHM 1 0 2W 57668 CRB20FXE 100E AlA1R7012 322 3097 00 RES FXD METAL FILM 100 OHM 196 0 2W 57668 CRB20FXE 100E AlA1R7013 322 3105 00 RES FXDMETAL FILM 121 OHM 1 0 2W 57668 CRB20FXE 121E AlA1R7014 322 3154 00 RES FXD METAL FILM 392 OHM 196 0 2W 57668 RB20FX392E AlA1R7015 322 3154 00 RES FXD METAL FILM 392 OHM 196 0 2W 57668 RB20FX392E AlA1R7020 322 3310 00 RES FXD FILM 16 5K OHM 1 0 2W 57668 CRB20FXE 16 5 AlA1R7021 321 0038 00 RES FXD FILM 24 3 OHM 196 0 125W 57668 CRBIAFXE 24 3 1 187022 322 3306 00 RES FXD METAL FILM 15 0K OHM 1 0 2W 57668 CRB20FXE 15K0 AlA1R7023 322 3097 00 RES FXD METAL FILM 100 OHM 196 0 2W 57668 CRB20FXE 100E AlA1R7024 322 3193 00 RES FXD METAL FILM 1K OHM 1 0 2W 57668 CRB20FXE 1K00 AlA1R7025 322 3193 00 RES FXD METAL FILM 1K 0HM 1 0 2W 57668 CRB20FXE 1K00 AlA1R7026 322 3193 00 RES FXD METAL FILM 1K OHM 196 0 2W 57668 CRB20FXE 1K00 AlA1R7027 322 3097 00 RES FXD METAL FILM 100 OHM 1 0 2W 57668 CRB20FXE 100E 1 187028 322 3068 00 RES FXD METAL FILM 49 9 OHM 0 1 0 2W 57668 CRB20FXE 49E9 1 18
105. 4R 1062 322 3364 00 RES FXD FILM 60 4K OHM 196 0 2W 57668 CRB20FXE 60K4 A4R 1063 322 3297 00 RES FXD FILM 12 1K OHM 196 0 2W 57668 CRB20FXE 12K1 A4R 1064 322 3289 00 RES FXD METAL FILM 10K OHM 1 0 2W 57668 CRB20FXE A4R 1065 322 3364 00 RES FXD FILM 60 4K OHM 196 0 2W 57668 CRB20FXE 60K4 A4R1066 322 3297 00 RES FXD FILM 12 1K OHM 196 0 2W 57668 CRB20FXE 12K1 A4R1070 322 3289 00 RES FXD METAL FILM 10K OHM 1 0 2W 57668 CRB20FXE A4R 1071 315 0100 00 RES FXD FILM 10 OHM 5 0 25W 01121 CB1005 A4R 1072 315 0100 00 RES FXD FILM 10 OHM 5 0 25W 01121 1005 8 32 1502B MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A4 A4R2030 A4R2031 A4R2040 A4R2041 A4R2042 A4R2043 A4R2045 A4R2046 A4R2047 A4R 2048 A4R 2049 A4R2050 A4R2051 A4R 2052 A4R 2053 A4R2054 A4R3020 A4R 3021 A4R 3032 A4R 3033 A4R 3040 A4R 3050 A4R 3051 A4R 3061 A4R 3062 A4R 3070 A4R3071 A4R 3080 A4T1020 1502B MTDR Service Manual Tektronix Part Number 670 9291 315 0300 00 315 0103 00 315 0101 00 315 0511 00 315 0101 00 315 0101 00 315 0121 00 315 0473 00 315 0243 00 315 0101 00 315 0562 00 315 0101 00 315 0203 00 315 0101 00 315 0562 00 315 0752 00 315 0100 00 322 3344 00 317 0027 00 317 0027 00 322 3268 00 315 0100 00 315 0100 00 322 3396 00 321 0631 03 322 3389 00 321 0645 00 321 0645 00 120 0582 00 Discontd Qty amp Descri
106. 5 200V SQ CAP FXD CER DI 1000P F 596 200V SQ CAP FXD CER 01 1000 5 200 SQ CAP FXD CER DI 0 47UF 596 50V SQ CAP FXD CER DI MLC 0 22UF 2096 50V Z5U CAP FXD CER DI 1000P F 596 200V SQ Mfr Code 80009 80009 80009 80009 80009 80009 81855 80009 81855 31433 31433 31433 31433 31433 31433 31433 04222 31433 31433 1502B MTDR Service Manual Mfr Part Number 160 4412 02 160 4412 03 160 4412 06 160 4412 07 160 4412 08 160 4412 09 LTC 7P 146 0079 00 LTC 7P 114 224 5 5 114 224 5 5 114 224 5 5 114 224 5 5 C322C102 265CA C322C102 265CA C322C102 265CA SR305C474J 114 224 5 5 C322C102 265CA Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1C1040 1 1 1041 A1A1C1042 A1A1C1043 A1A1C2010 A1A1C2011 A1A1C2012 A1A1C2013 A1A1C2014 A1A1C2015 1 1 2016 A1A1C2020 A1A1C2021 A1A1C2030 A1A1C2031 1 1 2032 A1A1C2033 A1A1C2034 A1A1C2035 A1A1C2036 A1A1C2037 A1A1C2038 A1A1C2039 A1A1C2040 A1A1C2041 A1A1C2042 A1A1C2043 A1A1C2044 A1A1C2045 A1A1C2046 A1A1C3020 A1A1C3021 Tektronix Part Number 670 9285 XX 281 0925 01 281 0925 01 290 1087 00 281 0925 01 281 0925 01 290 0748 00 281 0925 01 281 0925 01 281 0925 01 283 0111 04 283 0238 00 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01
107. 6 Pre Regulator Battery Charger Deep Discharge Protection The secondary voltage is full wave rectified by CR1010 and filtered by capacitor C1010 The large value of this capacitor allows it to supply energy to the instrument between half cycles of the line voltage Integrated circuit U1010 is a pulse width modulator switching regulator controller It oscillates at approximately 70 kHz and provides drive pulses to switching transistors Q1010 and 1011 The output pulses from these transistors are filtered to DC by flyback rectifier CR2010 choke L1010 and capacitors C2010 and C2012 The resulting 16 6 VDC is fed back to the regulator U1010 by voltage divider R1016 and R1015 It is then compared to a 2 5 VDC reference voltage from 01011 To increase the output voltage 01010 increases the pulse width of the drive to Q1010 and Q1011 To reduce the output voltage U1010 decreases the pulse width to Q1010 and Q1011 This assures that a constant 16 6 VDC is maintained Resistor R1010 acts as acurrent sensing shunt in the pre regulator return line In the event that a circuit fault draws excess current the voltage developed across R1010 and filtered by R1011 R1012 and C1011 will cause U1010 to reduce the pulse width of the pre regulator This protects the pre regulator from damage due to overload The battery charger consists of a linear regulator integrated circuit U2010 and associated components U2010 is connected as a current sou
108. 63 Col X Seg 62 1 Col X Seg 1 63 Col X Seg 0 64 Shift Register Detail Figure 5 20 Shift Register The display memory is an 8k X 8 RAM only 4k X 8 is used located on the Row Driver Controller Board The display memory stores the current bit pattern generated by the processor on the Main Board The processor interrupts the controller periodically and places a new bit pattern in the display memory The controller then reads the bit pattern out of the display memory formats it and sends it to the column drivers The controller located on the Row Driver Controller Board generates control and timing signals for the row and column drivers and formats bit pattern data stored in the display memory which is then sent to the column drivers The function of the controller is to read bit pattern data from the display memory and format it This data 15 then sent along with control and timing signals to the column and row drivers which drive the LCD to provide the pattern on the display The row driver requires a start pulse at the beginning of each frame 64 latch pulses following that to scan the start pulse down the rows and a framing signal to generate the AC select voltage These signals are generated by the controller as shown in the row driver timing diagram Figure 5 18 The controller running at a clock rate of 0 625 MHz generates ST LP and FR with the following periods ST 8 ms LP 125 us FR 16ms 9
109. 7029 322 3342 00 RES FXD FILM 35 7K OHM 1 0 2W 57668 CRB20FXE 35K7 AlA1R7030 322 3222 00 RES FXD METAL FILM 2 00K OHM 1 0 2W 57668 CRB20FXE 2K00 AlA1R7031 322 3306 00 RES FXD METAL FILM 15 0K OHM 1 0 2W 57668 CRB20FXE 15K0 1 187032 321 0720 00 RES FXD FILM 60K OHM 196 0 125W 91637 CMF55 116 G 60001FT AlA1R7033 322 3269 00 RES FXD FILM 6 19K OHM 196 0 2W 91637 CCF501G61900F AlA1R7034 322 3068 00 RES FXD METAL FILM 49 9 OHM 0 1 0 2W 57668 CRB20FXE 49 9 9 16 15028 MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1R7040 A1A1R8010 A1A1R8011 A1A1R8012 A1A1R8013 A1A1R8014 A1A1R8020 A1A1R8021 A1A1R8022 A1A1R8023 A1A1R8024 A1A1R8025 A1A1R8026 A1A1R8027 A1A1R8028 A1A1R8040 A1A1R8041 A1A1R8042 A1A1R8043 A1A1R8044 A1A1R8045 A1A1R8046 A1A1R8047 A1A1R9010 A1A1R9011 1 1 9012 Tektronix Part Number 670 9285 322 3001 00 321 0038 00 321 0312 00 321 0631 00 322 3126 00 322 3068 00 322 3193 00 322 3325 00 322 3283 00 322 3289 00 322 3097 00 321 0174 00 322 3306 00 322 3306 00 322 3306 00 321 0058 00 321 0782 03 321 0058 00 321 0782 03 322 3128 00 322 3205 00 321 0282 00 321 0620 00 321 0282 00 321 0620 00 322 3318 00 322 3318 00 322 3318 00 322 3289 00 322 3114 00 322 3258 00 322 3143 00 Effective B021151 R010100 B020617 B020798 8020817 R010100 8020617 8020798 8020817 15028 MTDR S
110. 71 CA31060E A1A1U9030 156 0496 00 IC LINEAR VOLTAGE REGULATOR RC4194D 34333 5064194 AlA1VR3030 152 0647 00 DIODE ZENER 6 8V 5 0 4W 1N957B 04713 1N957B 030 152 0514 00 DIODE ZENER 10V 196 0 4W M 741040 04713 MZ4104D 9 20 15028 MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A2 A2C1011 A2C1015 A2C2010 A2C2011 A2C2020 A2C2021 A2C2022 A2C2023 A2C2024 A2C2025 A2C2026 A2C2027 A2C2028 A2C2030 A2C2031 A2C2032 A2C2033 A2C2034 A2C3010 A2C3020 A2C3021 A2C3022 A2C3023 A2C3030 A2C3031 A2C3032 A2C3033 A2C3034 A2J1020 A2 3030 Tektronix Part Number 672 1251 283 0359 00 283 0359 01 281 0925 01 281 0925 01 281 0925 01 290 0974 00 290 0974 00 281 0925 01 281 0925 01 283 0492 00 283 0492 00 283 0492 00 283 0492 00 281 0925 01 283 0492 00 283 0492 00 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01 281 0925 01 290 0919 00 290 0919 00 281 0925 01 281 0925 01 281 0925 01 131 3147 00 131 1857 00 Effective B020820 1502B MTDR Service Manual Discontd Qty Name amp Description CIRCUIT BD ASSY FRONT PANEL CAP FXD CER DI 1000PF 10 200V SQUARE CAP FXD CER DI 1000PF 5 200V SQUARE CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD ELCTLT 10UF 20 50VDC AL CAP FXD ELCTLT 10UF 20 50VDC AL CAP F
111. 7668 57668 57668 56845 57668 Mfr Part Number CRB20 FXE10E0 CRB14 24 3 CEAD17401F CEA TO 1 12 5K CCF501G 200R OF CRB20 FXE 49E9 CRB20 FXE 1K00 CRB20 FXE 23K7 CRB20 FXE 8K66 CRB20 FXE 10K0 CRB20 FXE 100E 5043ED634ROF CRB20 FXE 15K0 CRB20 FXE 15K0 CRB20 FXE 15K0 321 0058 00 PME5540 OHM 0 25 321 0058 00 PME5540 OHM 0 25 CRB20 FXE210E CRB20 FXE 1K33 321 0282 00 CMF55 116 D 84500CT 321 0282 00 CMF55 116 D 84500CT CRB20 FXE 20K0 CRB20 FXE 20K0 CRB20 FXE 20K0 CRB20 FXE 10K0 CRB20 FX150E CCF50 2 64751FT CRB20 FXE 301E 8 17 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1R9013 A1A1R9014 A1A1R9015 A1A1R9020 A1A1R9021 A1A1R9022 A1A1R9023 A1A1R9024 A1A1R9025 A1A1R9026 A1A1R9027 A1A1R9030 A1A1R9031 A1A1R9032 A1A1TP 1040 1 1 1041 1 1 2040 1 1 3040 1 1 3041 1 1 4020 1 1 4021 1 1 4040 1 1 6010 1 1 7010 1 1 9010 1 1 9011 1 1 9040 1 1 9041 A1A1U1010 1 101011 1 101012 8 18 Tektronix Part Number 670 9285 XX 322 3306 00 322 3310 00 322 3342 00 321 0038 00 322 3097 00 322 3280 00 322 3097 00 322 3222 00 322 3306 00 322 3234 00 322 3126 00 322 3371 00 522 3331 00 311 0633 00 214 0579 02 214 0579 02 214 0579 02 214 0579 02 214 0579 02 214 0579 02 214 0579 02 214 0579 02 214 0579 02 214 0579 02 214 0579 02 214
112. 7X318 390 0964 00 17 348 0419 00 2 FOOT CABINET FRONT BLK POLYURETHANE 7X318 348 0419 00 18 211 0507 00 4 SCR MACH 6 32 X 0 312 PNH POZ 01 211 0507 00 19 348 0420 01 2 FOOT CABINET REAR BLK POLYURETHANE 7X318 348 0420 01 20 213 0451 02 4 SCR EXT RLV 10 24 X 1 75 SST PSVT 80009 213 0451 02 21 354 0175 00 4 RING RTNG TYPE E EXT U O 0 188 2 013 354 0175 00 22 348 0444 00 4 SEAL BOLT 0 186 X 0 443 0 05 THK 80009 348 0444 00 23 386 4704 00 2 3 8 X 0 434 STL 7X318 386 4704 00 24 213 0183 00 2 SCR TPG TF 6 20 X 0 5 TYPEB PNH POZ 93907 ORD BY DESCR 25 131 1705 00 R010100 B025092 1 CONN RCPT ELEC POWER INTERCONNECT 80009 131 1705 00 131 1705 01 8025093 1 CONN RCPT ELEC POWER INTERCONNECT 80009 131 1705 01 26 213 0012 00 2 SCR TPG 4 40 X 0 375 FLH POZ 83385 BY DESCR 10 5 1502B MTDR Service Manual Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont aa Tektronix Part Serial No Serial No Mfr Number Number Effective Discontd Qty Name amp Description Code Mfr Part Number FIG 10 1 CABINET Con t 21 337 3225 00 8025000 8036153 1 SHIELD ELEC GROUND AROUND AC RCPT 80009 337 3225 00 28 200 3210 00 1 COVER TUBE CAP CLOSED ALUMINUM 80009 200 3210 00 29 354 0675 00 010100 R 020413 1 O RING 0 5 X 0 625 OD 5H194 2 014 354 0688 00 R020414 O RING 0 424 X 0 625 OD X 0 093 THK 83259 2 111 30 200 3211 00 1 COVER
113. 8 19 20 21 22 823 24 929 26 26 29 30 231 32 33 34 1502B MTDR Service Manual Tektronix Part Number 213 1089 00 386 5307 00 386 5307 01 614 0389 01 348 0477 00 348 0477 00 348 1116 00 348 0477 00 348 0976 00 348 1144 00 348 0920 00 331 0502 00 342 0731 00 342 0731 01 220 0407 00 337 2193 02 337 2193 04 211 0661 00 129 1092 00 210 1307 00 210 1002 00 334 8135 00 650 3714 00 Serial No Effective R010100 B021135 B025496 R010100 B021135 B021135 B037138 R010100 B021135 R010331 B035825 R010100 B035825 B035976 Serial No Discont d B021134 B025495 B021134 B037137 B021134 B035824 B035824 B037458 Qty Name amp Description D p Lr 29 L3 N N A FRAME AND FRONT PANEL Con t SCREW TYPE F 6 32 X 500 FLH POS 410 SS SUBPANEL FRONT SUBPANEL FRONT FRONT PANEL ASSEMBLY SEAL RBR STRIP 0 94W X 0 062THK X 28 01 SEAL RBR STRIP 0 94W X 0 062THK X 28 01 SEAL CONDUCTIVE 0 094 X 0 062 SEAL RBR STRIP 0 94W X 0 062THK X 28 01 SHLD GSKT ELEC 2 53 X 3 255 X 0 62 SILICON GASKET COND ELASTOMER W AL SHLD GSKT ELEC PUSH BUTTON WINDOW DSP 2 295 X 4 35 X 0 125 GLASS CKT BD ASSY FRONT PANEL SEE 2 REPL SCR ASSEM WSHR 6 32 X 0 312 PNH POZ CONN HDR PCB MALE SEE 2 REPL BUS CONDUCTOR SHUNT SHORTING FEMALE CONN HDR PCB MALE SEE 2 RE
114. A list of assemblies 15 found at the beginning of the replaceable electrical parts list Assemblies are listed in numerical order When the complete component number of a part is known this list identifies the assembly in which the part is located The manufacturer code number to manufacturer cross index provides codes names and addresses of manufacturers of components listed in the replaceable electrical parts list Abbreviations conform to ANSI standard Y 1 1 Column 1 of electrical parts list A numbering method is used to identify assemblies subassemblies and parts An example of this numbering method and typical expansions is as follows A23A2R1234 A23 A2 R1234 l l Assembly Subassembly Circuit Number Number Number Read resistor 1234 of subassembly 2 of assy 23 Only circuit numbers appear on the schematics and circuit board illustrations Each schematic and illustration is marked with its assembly number Assembly numbers are also marked on the mechanical exploded view located in the replaceable mechanical parts list A component number is obtained by adding the assembly number prefix to the circuit number This parts list is arranged by assemblies in numerical sequence e g assembly A1 with its subassemblies and parts precedes A2 with its subassemblies and parts Chassis mounted parts have no assembly number prefix and are illustrated at the end of the replaceable mechanical parts list Replaceable Electrical Par
115. AL FILM 10 0K OHM 1 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W Mfr Code 04713 04713 04713 01295 80009 80009 04713 04713 21845 80009 04713 01295 04713 04713 04713 04713 01295 80009 80009 04713 01295 57668 57668 57668 57668 57668 57668 57668 57668 57668 57668 57668 Mfr Part Number 2N5087RLRP SPF 3040 2N 3839 SKA4504 151 0353 00 151 0232 00 2N2918 2N 3839 F1585 151 0354 00 2N3810 SKA4504 2N3839 MD918 2N3839 MD918 SKA4504 151 0353 00 151 0232 00 2N2918 SKA4504 CRB20 FXE 475E CRB20 FXE CRB20 FXE CRB20 FXE CRB20 FXE 100K CRB20 FXE 20K0 CRB20 FXE 100E CRB20 FXE CRB20 FXE 10K0 CRB20 FXE CRB20 FXE 8 13 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1R1030 A1A1R1031 A1A1R1032 A1A1R1033 A1A1R1035 A1A1R2010 1 1 2011 A1A1R2012 A1A1R2013 A1A1R2014 1 182015 A1A1R2030 A1A1R2031 A1A1R2033 A1A1R2034 A1A1R2040 1 182041 A1A1R2042 A1A1R2043 A1A1R3010 A1A1R3020 A1A1R3030 A1A1R3031 A1A1R3032 A1A1R 3033 A1A1R3034 A1A1R3035 A1A1R3036 A1A1R3037 A1A1R3038 A1A1R3039 A1A1R3040 8 14 Tektronix Part Number 670 9285 321 0523 00 321 0523 00 322 3431 00 307 0446 00 321 0756 00 322 3097 00 322 3318 00 322 3385 00 322 3385 00 307 0446 00 307 0446 00 322 3239 00 322 3239 00 322 3293 00 311 0634 00 322 3139 00 322 3134 00 322 3134 00 322 3126 0
116. B SET REF W DOT SET FOR 90 SHELL KNOB DOVE GRAY W INDEX DOT EACH KNOB INCLUDES SETSCREW 5 40 X 0 125 STL HEX SKT CONN RCPT ELEC BNC FEMALE SHORTING DUST COVER ASSEMBLY SUBPART OF ASSEMBLY 5 ABOVE SWITCH ROTARY 1503B 3C ONLY SWITCH ROTARY SEE 25 3012 RESISTOR VARIABLE SEE 2 3020 REPL SWITCH ROTARY SEE 253020 REPL SWITCH ROTARY SEE 253021 REPL SWITCH ROTARY SEE 253022 REPL SWITCH ROTARY 1503B 3C ONLY RESISTOR VARIABLE SEE A2R2024 REPL RESISTOR VARIABLE SEE A2R1022 REPL Mfr Code 0 R05 0 R05 0 R05 0 01 91836 5 400 EACH SWITCH AND VARIABLE RESISTOR INCLUDES NUT PLAIN HEX 0 25 32 X 0 312 WSHR FLAT 0 25 X 0 375 X 0 02 STL CD PL EACH VARIABLE RESISTOR INCLUDES O RING 0 25 X 0 062 OD XSECT SEAL ROTARY POT 0 125 X 0 187 00 SEAL CONT SHAFT 0 125 X 0 187 OD X 0 3 L PUSH BUTTON MENU 0 523 X 0 253 PUSH BUTTON VIEW INPUT PUSH BUTTON VIEW STORE PUSH BUTTON VIEW DIFF PUSH BUTTON STORE MARKER IDENT MARKED 1502B MARKER IDENT MARKED 1502B 1502B MTDR Service Manual Mfr Part Number 366 2097 00 366 2104 00 366 2098 00 ORDER BY DESCR 152 1729 650 3697 00 2X 20319 402 ORD BY DESCR 2 010 5 455 70 348 1145 00 348 1145 01 366 0655 05 366 0655 01 366 0655 02 366 0655 03 366 0655 04 334 6664 00 334 6664 01 Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont Fig amp Index Number FIG 10 2 17 1
117. Black Grounded neutral Blue White Grounded earth Green Yellow Green Removing the DC Battery Banana Plugs 2 Remove the plugs from the power supply module 1 Remove both nuts from the banana plugs see Figure 7 4 next page NOTE During reassembly be aware that the positive plug is on the side closest to the Power Supply Board The order of parts must be plug solder lug with capacitor plastic shouldered washer and on the other side of the chassis wall the mica insulating washer metal washer then nut The negative plug sequence is plug solder lug the other side of the capacitor plastic shouldered washer and on the other side of the chassis wall the nut 1502B MTDR Service Manual 1 7 Maintenance Removing the Main Board 7 8 EA E Figure 7 4 DC Battery Banana Plugs From the top side of the instrument remove the multi colored cable power supply from the Main Board Turn the instrument upside down to expose the top of the Main Board Remove the three multi colored cables from the component side of the Main Board This can be accomplished by inserting a small straight blade screwdriver in the key and gently prying the connector from the board Take care to guide the connectors straight off to avoid bending the pins Remove the eight screws and the center spacer post with washer and locknut that fasten the Main Board to the chassis Re
118. C 01855 EAGLE PICHER INDUSTRIES INC ELECTRONICS DIV 91637 DALE ELECTRONICS INC 1502B MTDR Service Manual Address 8 WHATNEY PO BOX 19515 45 SALEM ST 2601 WAYNE ST PO BOX 269 HWY 20 W PO BOX 858 401 N BROAD ST 400 REIMANN AVE 800 E NORTHWEST HWY 14150 SW KARL BRAUN DR PO BOX 500 561 HILLGROVE AVE PO BOX 10373 COUPLES DEPT C AND PORTER STS PO BOX 47 2064 12TH AVE PO BOX 609 City State Zip Code IRVINE CA 92713 PROVIDENCE RI 02907 ENDICOTT NY 13760 3272 FORT DODGE 50501 PHILADELPHIA PA 19108 1001 SANDWICH IL 60548 1846 DES PLAINES IL 60016 3049 BEAVERTON OR 97077 0001 LA GRANGE IL 60525 5914 OPLIN MO 64801 COLUMBUS NE 68601 3632 8 5 Replaceable Electrical Parts Replaceable Parts List Assy Tektronix Serial No Serial No Mfr Number Part Number Effective Discontd Qty amp Description Code Mfr Part Number CIRCUIT BOARD ASSEMBLIES Al 672 1253 00 R010100 B021134 CKT BD ASSY MAIN STD INSTR W EPROM 80009 672 1253 00 672 1253 01 8021135 8021151 BD ASSY MAIN W EPROM amp BATTERY 80009 672 1053 01 672 1253 02 8021152 8035824 BD ASSY MAIN BD W EPROM amp BATTERY 80009 672 1253 02 672 1253 03 8035825 8036453 BD ASSY MAIN BD W EPROM amp BATTERY 80009 672 1253 03 672 1253 04 8036454 8037359 BD ASSY MAIN W EPROM amp BATTERY 80009 672 1253 04 672 1253 05 8037360 BD ASSY MAIN W EPROM amp BATTERY 80009 672 1253 05 MOD ONLY
119. C MOUNT SWITCH ROTARY NOISE PC MOUNT SWITCH ROTARY HORIZONTAL SCALE SWITCH ROTARY HORIZONTAL SCALE SWITCH ROTARY VP COURSE SWITCH ROTARY VP COURSE SWITCH ROTARY NOISE PC MOUNT SWITCH ROTARY NOISE PC MOUNT IC LINEAR BIPOLAR OP AMP DUAL IC LINEAR BIPOLAR COMPARATOR DUAL IC CONVERTER CMOS D A 8 BIT 400NS DIGTIAL HCMOS GATE QUAD 2 INPUT OR IC CONVERTER TTL A D 8 BIT 100US SAR IC DIGITAL HCMOS MUX ENCODER DUAL IC DIGITAL HCMOS MUX ENCODER DUAL IC DIGITAL HCMOS GATE QUAD 2 INPUT NOR IC DIGITAL HCMOS GATE QUAD 2 INPUT NOR IC DIGITAL HCMOS GATE QUAD 2 INPUT NOR Mfr Code 57668 57668 12697 01121 01121 56866 71590 71590 71590 71590 71590 91073 04426 91073 04426 91073 04426 91073 04426 18324 04713 24355 01295 80009 0 R04 0 R04 04713 04713 04713 Mfr Part Number CRB20 100K CRB20 100K CM45241 316A304 316A304 19 2LL199NB021074 2LL199NB021074 2LL199NB021074 2LL199NB021074 2LL199NB021074 51Y 23669 47 012 0014 51YY23673 47 006 0065 51YY23671 41 012 0011 51YY 23669 41 012 0014 NE532 LM393N AD 7524 N SN74HC32N 156 2589 00 TC74HC253AP TC74HC253AP MC74HC02AN MC74HC02AN MC74HC02AN 8 23 Replaceable Electrical Parts Replaceable Parts List Cont Assy Tektronix Serial No Serial No Mfr Number Part Number Effective Discontd Qty amp Description Code Mfr Part Number A2 672 1251 CIRCUIT ASSY FRONT PANEL Con t A2U30
120. C3030 and C3031 serve to filter noise introduced to the 16 VDC supply by the EL power supply The display heater circuitry regulates the application of power to the display heater see Indium Tin Oxide Heater later in this chapter for more information When the display thermistor divider senses the display temperature has dropped below 10 C the heater can be turned on if the control signal HEAT ENABLE is not asserted For reasons of power economy the chart recorder and display heater are not allowed to operate concurrently The processor does this by asserting HEAT ENABLE while making a chart recording When HEAT ENABLE is low N channel FET Q2020 is off making the voltage on the side of the comparator U2020A approximately 5 VDC This will allow the side chart recorder to always be greater than the side display thermistor divider voltage The output of the comparator will be 16 VDC which turns off P channel FET Q1020 This turns off the power to the display heater When HEAT DISABLE 15 high 02020 will turn on and the voltage on the side of the comparator will be approximately 2 5 volts When the display thermistor divider voltage side is above 2 5 volts about 10 C the comparator output will be 0 V which will turn on Q1020 This will turn on the heater As the temperature rises above 10 C the thermistor divider voltage will be less than 2 5 V and Q1020 will turn off shutting off power to the heater
121. CAP OPEN ALUMINUM 80009 200 3211 00 31 354 0675 00 R010100 R020413 l O RING 0 5 X 0 625 OD 5H194 2 014 354 0688 00 R020414 1 O RING 0 424 X 0 625 OD X 0 093 83259 2 111 32 331 0501 00 1 WINDOW VIEW POLYCARB OPTICAL GRADE 80009 331 0501 00 200 3452 00 R010100 024999 l COVER BATTERY ALUMINUM 80009 200 3452 00 200 3452 01 B025000 1 COVER BATTERY ALUMINUM 80009 200 3452 01 33 333 3434 00 010100 8021134 1 PANEL FRONT BATTERY PORT 2 72 X 3 562 AL 80009 333 3434 00 333 3434 01 8021135 1 PANEL FRONT BATTERY PORT 2 72 X 3 562 AL 5400 333 3434 01 34 214 1573 00 2 THUMBSRCREW 6 32 X 0 656 X 0 312 SST 06540 6130 55 0632 35 210 1160 00 2 WSHR FLAT 0 129 X 0 25 X 0 031 TEFLON 06445 ORD BY DESCR 36 348 0432 00 R010100 B021134 1 GASKET FRONT PANEL 2K262 348 0432 00 348 1143 00 B021135 B035824 1 GASKET COND ELASTOMER W ALUMINUM 0JRZ5 348 1143 00 348 1143 01 B035825 GASKET BATTERY 0 062 X 2 600 X 2 600 0 25 348 1143 01 334 6892 00 1 LABEL MARKED CAUTION 01472 334 6892 00 334 6864 02 025330 1 MRKR IDENT W VOLTAGE INFORMATION 01472 334 6864 02 STANDARD ACCESSORIES 37 161 0066 09 1 CA ASSY PWR 3 0 75MM SQ 220V 99 0L 53109 86511000 OPTION A1 EUROPEAN ONLY 38 161 0066 10 1 CA ASSY PWR 3 0 75MM SQ 250V 2 5 METERS 53109 BS 13 H05VVF3G0 OPTION A2 UNITED KINGDOM ONLY 39 161 0066 11 1 ASSY PWR 3 1 00MM SQ 250V 10AMP 2 5 53109 SAA 3 0D3CCFC3 OPTION A3 AUSTRALIA ONLY 40 161 0066 12 1 CA ASSY PWR 3 18 AWG 25
122. D 810 Method 514 Procedure XI faces Part 2 MIL T 28800C Style A Front cover off Loose Cargo Bounce Water Resistance Operating Splash proof and drip proof Non operating Salt Atmosphere Watertight with 3 feet of water above top of case Front cover on Withstand 48 hours 20 solution without corrosion Operates after test with cover on non operating MIL STD 810 Method 510 Procedure Sand and Dust Washability Fungus Inert Materials are fungus inert continued next page 1502B MTDR Service Manual 3 3 Specifications Characteristic Performance Requirement Supplemental Information Electromagnetic Compatibility VDE 0871 Class B MIL T 28800C CE02 CE04 C502 C506 REO2 MIL STD 461A notice 4 E L RE02 RS03 RS03 1 from 14 kHz to 10 GHz Radiated Susceptibility MIL STD 461A notice 4 EL method MIL STD 462 notice 3 Limited to 1 V m greater than 1 for RS03 RS03 1 GHz displayed noise characteristics performance shall be 10 mp peak or less with 50O termination con nected to RF input 16 averages Physical Characteristics Characteristic Description Weight without cover 14 25 6 6 46 kg with cover 15 75 6 7 14 kg with cover chart recorder and battery pack 19 75 Ibs 8 96 kg Shipping Weight domestic 25 5 105 11 57 kg export 25 5 105 11 57 kg Height 5 0 inches 127 mm Width with handle 12 4 inches 315 mm wit
123. DEG POZ TERMINAL LUG 0 146 ID LOCKING Mfr Code 01536 53387 22562 58050 0 01 0 01 OKBO1 OKBO1 80009 91094 80009 80009 80009 80009 OKBO1 OKBO1 S3629 S3629 93907 86928 Mfr Part Number 821 01655 024 2514 5002UB 65576 131 082 3644 5510 211 0507 00 210 0561 00 211 0507 00 210 0561 00 253 0188 00 ORD BY DESCR 220 0547 01 211 0105 00 441 1685 00 211 0105 00 ORD BY DESCR ORD BY DESCR 031 1673 FEK 031 1666 ORD BY DESCR A 313 158 2 10 13 Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont kaa Tektronix Part Serial No Serial No Mfr Number Number Effective Discontd Qty Name amp Description Code Mfr Part Number FIG 10 3 620 0477 POWER SUPPLY ASSEMBLY Con t CHASSIS MOUNTED PARTS Con t 23 211 0658 00 1 SCR ASSEM WA 6 32 X 0 312 PNH POZ 78189 551 060545 0 24 134 0014 00 2 PLUG TIP BANANA 1 125 X 0 375 LSTUD 74970 108 0750 001 25 210 0202 00 2 TERMINAL LUG 0 146 ID LOCKING 06928 373 158 2 26 210 0975 00 2 WSHR SHLDR 0 14 X 0 375 OD X 0 1 DELRUN 80009 210 0975 00 27 210 0457 00 2 NUT PL ASSEM WA 6 32 X 0 312 0KBO1 BY DESCR 28 210 0803 00 1 WSHR FLAT 0 15 X 0 375 OD X 0 032 12327 ORDBYDESCR 29 210 0933 00 1 INSULATOR WSHR 0 165 0 625 OD X 0 002 01 210 0933 00 30 441 1684 00 R010100 B021134 1 CHASSIS PWR SUPPLY 80009 441 1684 00 441 1684 01 B021135 1 CHASSIS PWR SUPPLY 80009 441 1684 01 334 3379 01 1 MARKER IDENT MKD G
124. Display Drive Voltage Contrast Temperature Compensation The Front Panel Board contains most of the instrument control as well as some circuitry for the display module A block diagram of the Front Panel Board is shown in Figure 5 13 next page The push button switches are normally open momentary switches When depressed these switches tie the inputs of NOR gate latches 03021 03022 and 03023 to 5 VDC setting the latches The latches are reset by control signal ADCRD The processor updates the instrument configuration by periodically reading the state of the latches through multiplexers U2024 03025 and 03031 5 25 Circuit Descriptions Push Button Switches MENU VIEW INPUT VIEW STORE VIEW DIFF Cm rn O r STORE IMPEDANCE NOISE FILTER FEET DIV PULSEWIDTH Vp E BE B B B B x Rotary Binary Switches Cn2zorn rnmr o r cc 50 Pin Connector s Data Bus Address Control Bus ANALOG DIGITAL CONVERTER HORIZONTAL POSITION VERTICAL POSITION VERTICAL SCALE MEM Resistive Shaft Encoder Figure 5 13 Front Panel Block Diagram 5 26 From Temp Sensors LCD Heater Drive Circuitry To LCD Heater
125. Distance Div is ft div Exit by pressing MENU until the instrument returns to normal operation If the instrument power is turned off this procedure must be repeated when the instrument is again powered up The metric default can be changed to standard default See the Maintenance chapter of this manual for details Pull the POWER switch on the front panel If a message does not appear on the display within a few seconds turn the instrument off If start up assistance needed Push MENU button 1502B ROM version 5 02 Ethernet Copyright 1992 Tektronix Redmond OR Figure 6 1 Typical Start Up Display CAUTION There are some failure modes that could permanently damage the LCD if the power is left on more than a minute or so 2 Observe that the LCD characters and waveform are legible If the LCD is too dark or smeared or if the display has patches of low contrast refer to the Adjustment Procedures section of this chapter 29 Fc E F Figure 6 2 Waveform on the Display 1502B MTDR Service Manual Calibration NOTE If the LCD does not appear to be working properly refer to the Troubleshooting section in the Maintenance chapter as well as the Circuit Description chapter of this manual EL Backlight The EL backlight should come on with power up The LCD will have a light green glow 1 Press MENU 2 Use the POSITION control to scroll to Setup Menu 3 Press MENU again 4 Use t
126. Driver Interface 5 38 Column Drivers 5 31 Controller 5 37 CPU and Display Memory Timing Diagram 3 9 CPU Interface 5 38 EL Backlight 5 40 General 5 29 ITO Heater 5 41 LCD Cell 5 30 Memory 5 37 Memory Interface 5 38 Row Driver 5 32 Block Diagram 5 31 Timing Diagram 5 34 Row Driver Interface 5 37 Row Drivers 5 31 Supply Voltages 5 33 SBE Cell 5 31 Shift Register 5 37 Driver Sampler 5 23 Bridge Bias 5 24 General 5 23 Power Supply Conditioner 5 24 Second Sampler 5 23 Trigger Pulse Shapers 5 24 Elapsed Time Indicator 5 22 Front Panel Analog to Digital Converter 5 27 Index 1 Index Block Diagram 5 26 Display Heater 5 28 Display Temperature Compensation 5 28 EL Backlight 5 28 General 5 25 Push Button Switches and Latches 5 25 Resistive Shaft Encoders 2 27 Rotary Binary Switches 5 27 Switch Multiplexers 5 27 Front End 5 23 Introduction 5 1 Option Port Interface Block Diagram 5 11 5 13 Buffers 5 12 General 5 10 Output Latch 5 12 Supply Control 5 11 Wiring Configuration 5 12 Power Supply Battery Charger 5 6 Block Diagram 5 4 DC to DC Converter 5 7 Deep Discharge Protection 5 6 General 5 4 Post Regulator 5 7 Pre Regulator 5 6 Primary Circuit 5 5 Processor Block Diagram 5 8 Processor System Address Decoding 5 9 Decoding 5 10 Display RAM Space 5 9 En
127. ES FXD FILM 3 01K OHM 1 0 2W RES FXD METAL FILM 10K OHM 1 0 2W RES FXD 0 1 OHM 5 1 0W RES FXD FILM 24 3K OHM 1 0 2W RES FXD CMPSN 2 7 OHM 5 0 125W RES FXD 1 1 OHM 5 1W Mfr Code 80009 57668 80009 57668 57668 57668 57668 57668 01121 80009 91637 57668 80009 01686 57668 57668 57668 57668 57668 57668 19701 57668 57668 91637 57668 57668 57668 56637 91637 01121 75042 1502B MTDR Service Manual Mfr Part Number 321 0296 00 CRB20 FXE 11K0 321 019 7 00 CRB20 FXE 953E CRB20 FXE 2K74 CRB20 FXE 2K49 CRB20 FXE 13K7 CRB20 FXE 1K00 BB2765 321 0245 00 CCF50 2 G46400FT CRB20 DYE 13K0 321 0001 00 T2B 79 4 CRB20 FXE 100K CRB20 FXE 51 1 CRB20 FXE CRB20 FXE 100 CRB20 FXE 100K CRB20 FXE 100K 5033ED 4K 220F CRB20 FXE 2K00 CRB20 FXE 1K00 CCF50G5111FT CRB20 FXE 3K01 CRB20 FXE 3K01 CRB20 FXE BW1 0 1 OHM CCF50 2F24301F BB2765 5P 20 1 1 OHM 5 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A3M A3A152010 A3A1T1030 A3A1T1031 A3A1TP1010 A3A1TP1020 A3A1TP2010 A3A1TP 2030 A3A1U1010 A3A1U1011 A3A1U1020 A3A1U1021 A3A1U1022 A3A1U1023 A3A1U1024 A3A1U2010 A3A1U2030 A3A1VR1012 Tektronix Part Number 670 9286 XX 260 2370 00 120 1608 00 120 0487 00 214 0579 02 214 0579 02 214 0579 02 214 0579 02 156 0933 00 156 1173 00 156 1225 00 156 1225 00 156 1173 00 156 0933 00 156 0366 00 156 1161 00 156 049
128. GE BUSSMAN ONLY FUSE CARTRIDGE 3AG 0 15A 250V FILTER RFI 1A 250VAC PWR CONN FILTER RFI 1A 115 230VAC 50 60HW XFMR RF TOROID 1980 TD 415 RES V SENSITIVE 1900P F 100A 130V SWITCH ROTARY VOLTAGE SELECTOR XFMR PWR DUAL PRI 115 230VAC 50 60HZ XFMR PWR DUAL PRI 115 230VAC 50 60HZ CIRCUIT BD ASSY POWER SUPPLY CAP FXD ELCTLT 3000UF 10 75 75V DI 0 01UF 2096 50V DI 1000PF 5 200V DI MLC 0 22UF 20 50V DI 1000PF 5 200V DI 1000PF 5 200V DI 51PF 5 200V DI 1UF 20 50V DI 1UF 20 50V CAP FXD ELCTLT 10UF 2090 25V CAP FXD ELCTLT 10UF 2090 25V CAP FXD CER DI 1UF 80 20 25V CAP FXD CER DI 1UF 80 20 25V CAP FXD CER DI 1UF 80 20 25V CAP FXD ELCTLT 100UF 20 25VDC AL CAP FXD CER DI 1UF 80 20 25V CAP FXD ELCTLT 100UF 20 25VDC AL Mfr Code 80009 80009 80009 80009 80009 80009 80009 80009 80009 80009 80009 24165 04222 31433 31433 31433 31433 04222 04222 04222 24165 24165 04222 04222 04222 1W344 04222 1W344 Mfr Part Number 283 0024 00 283 0167 00 159 0029 01 159 0054 00 119 1957 00 119 3488 00 120 1458 00 307 0449 00 260 2372 00 120 1607 00 120 1922 00 530268 AR205C103MAATRSTDII 322 102 2G5CA C114C224M5Y5CA 322 102 2 5 322 102 2 5 SR202A510 AA SR305C105MAATRSTDII SR3
129. ID COVER ASSEMBLY 7X318 650 3676 00 1 105 0684 01 2 LATCH ASSEMBLY 0 4 1 105 0684 01 2 213 0839 00 2 SCR TPG TF 4 24 X 0 5 L FLH POZ 80009 213 0839 00 3 214 0787 00 1 STEM LATCH ACCESS 80009 214 0787 00 4 204 0282 00 1 BODY LATCH ACCESS BOX DELRIN 80009 204 0282 00 5 214 2389 00 2 SWITCH 80009 214 2389 00 334 6861 00 1 MARKER IDENT MARKED 15028 01472 334 6861 00 062 9291 00 CARD INFO QUICK REFERENCE 01472 062 9291 00 334 8896 00 1 MARKER IDENT VOLTAGE WARNING LABEL 80009 334 8896 00 431 0331 00 UNIT 80009 437 0337 00 8 200 1805 00 2 COVER HDL LATCH 0JROS 200 1805 00 9 213 0739 00 2 SCR MACH 10 32 X 0 375 HEX HD SSTW NYLON 03038 213 0739 00 10 210 1231 00 2 WSHR SHLDR 0 82 X 0 9 X 0 07 FBR 80009 210 1231 00 11 386 3303 01 2 PLATE SECURING HANDLE STEEL 80009 386 3303 01 12 107 0035 00 4 DISC FRICTION 0 38 X 1 865 X 0 031 ASB 26262 107 0035 00 13 210 1501 00 B037303 4 WSHR FRICTION 1 820 X 0 388 30455 20GA 80009 210 1501 00 14 334 9302 00 1 MARKER IDENT MARKED TEKTRONIX 01472 334 9302 00 15 367 0204 01 8010100 8037302 1 HANDLE CARRY 11 7 L BLK VINYL W HDW 0 9 4 367 0204 01 347 0449 00 8037303 HANDLE CARRY BLACK VINYL 302 SST 80009 347 0449 00 16 390 0964 00 R010100 B024999 1 CABINET ASSY 7X318 390 0964 00 390 1068 00 8025000 8037105 1 ASSY CONDUCTIVE PLATE 7x318 390 1068 00 390 0964 00 B037106 1 CABINET ASSY
130. IDE NY 11377 2523 DOVER NH 03820 SCOTTSDALE AZ 85252 LEXINGTON MA 02173 7305 DEER PARK NY 11729 4605 WEST PALM BEACH FL SANTA ANA CA 92704 5948 HICKSVILLE NY 11802 8 3 Replaceable Electrical Parts Manufacturers Cross Index Cont Mfr Code 16546 17856 18324 18796 19701 1ES66 1W344 21847 22526 24165 24355 21014 31433 32997 34333 34371 34649 50434 53387 64537 54937 55680 56637 56845 56866 8 4 Manufacturer PHILIPS COMPONENTS DISCRETE PRODUCT DIV RES FACILITY SILICONIX INC SIGNETICS CORP MILITARY PRODUCTS DIV MURATA ERIE NORTH AMERICAN INC STATE COLLEGE OPERATIONS PHILIPS COMPONENTS DISCRETE PRODUCT DIV RESISTIVE PRODUCTS FACILITY MAXIM INTEGRATED PRODUCTS INC UNITED CHEMI CON INC FEL MICROWAVE INC DU PONT E I DE NEMOURS AND CO INC DU PONT ELECTRONICS DEPT SPRAGUE ELECTRIC CO ANALOG DEVICES INC NATIONAL SEMICONDUCTOR CORP KEMET ELECTRONICS CORP NATIONAL SALES HEADQUARTERS BOURNS INC TRIMPOT DIV SILICON GENERAL INC HARRIS CORP HARRIS SEMICONDUCTOR PRODUCTS GROUP INTEL CORP SALES OFFICE ST4 2 HEWLETT PACKARD CO OPTOELECTRONICS DIV MINNESOTA MINING MFG CO KDI ELECTRONICS INC SUBSIDIARY OF KDI CORP DEYOUNG MANUFACTURING INC NICHICON AMERICA CORP RCD COMPONENTS INC DALE ELECTRONICS INC QUALITY THERMISTOR INC Address 4561 COLORADO BLVD 2201 LAURELWOOD RD 4130 5 MARKET COURT 1900 W COLLEGE AVE
131. L FILM 100K OHM 1 0 2W RES VAR PLASTIC DUAL 10K 10 NO STOPS RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD FILM 40 2 OHM 196 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 10 OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD FILM 2 74M OHM 1 0 125W RES VAR PLASTIC DUAL 10K 10 NO STOPS RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD FILM 40 2K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W RES FXD METAL FILM 100K OHM 1 0 2W Mfr Code 63312 04713 04713 17856 57668 01121 5768 91637 02111 5768 57668 12697 57668 57668 57668 57668 57668 57668 91637 57668 57668 57668 07716 12697 57668 57668 91637 57668 57668 57668 57668 Mfr Part Number LPS15 1 2 IRFD9120 IRFD9120 VNO606L TA CRB20 FXE 100K ADVISE CRB20 FXE 100E CCF50 2 640201F 43 253 672 CRB20 FXE 100 CRB20 FXE 100K CM45241 CRB20 FXE 100K CRB20 FXE 100K CRB20 FXE 100K CRB20 FXE 100K CRB20 FXE 100K CRB20 FXE 100K CCF50 2G40R020FT CRB20 FXE 100K CRB20 FXE 10 0 CRB20 FXE 100K CEA 2 74 M OHM CM45241 CRB20 FXE 100K CRB20 FXE 100K CCF50 2 640201F CRB20 FXE 100K CRB20 FXE 100K CRB20 FXE 100K CRB20 FXE 100K 1502B MTDR Service Manual
132. LINEAR BIFET OP AMP DUAL LOW PWR IC LINEAR VOLTAGE REFERENCE 2 PIN IC DIGITAL HCMOS MULTIVIBRATOR IC LINEAR BIPOLAR OP AMP DUAL Mfr Code Mfr Part Number 80009 214 0579 00 80009 214 0579 00 80009 214 0579 00 80009 214 0579 00 80009 214 0579 00 80009 214 0579 00 80009 214 0579 00 80009 214 0579 00 80009 214 0579 00 80009 214 0579 00 80009 214 0579 00 80009 119 2369 01 04713 LM358N 04713 LM358N 01295 TL062CP 1ES66 1CL8069CCSQ2 04713 MC74HC221N 04713 LM358N 1502B MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont Assy Tektronix Serial No Serial No Mfr Number Part Number Effective Discontd Qty amp Description Code Part Number A9 670 6592 CIRCUIT ASSY POWER FUSE JACK OPTION 03 ONLY A9F9100 159 0266 00 FUSE CANISTER 3A 125V RADIAL LEAD 15915 2713 003 8 35 15028 MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont Assy Tektronix Serial No Serial No Mfr Number Part Number Effective Discontd Qty amp Description Code Part Number WIRE ASSEMBLIES W1010 174 0955 00 CA ASSY RF 50 OHM 4 75 L 80009 174 0955 00 FROM A4U1010 TO FRONT PANEL J 100 W2010 174 0950 00 CA ASSY SP ELEC 26 28 AWG 11 0L 80009 174 0950 00 FROM OPTION PORT W201 TO 1 1 2010 W2020 174 0954 00 WIRE ASSY POWER SUPPLY 4 28 AWG 80009 174 0954 00 FROM A3A1J 2010 TO BANANA ACK W201 W5040 174 0953 00
133. M TEST POINT 0 052 ID 0 169 H 0 465 L IC DIGITAL CMOS MISC NONVOLATILE CONTROL IC DIGITAL HCMOS FLIP FLOP DUAL J K IC LINEAR BIPOLAR COMPARATOR DUAL 1502B MTDR Service Manual Mfr Code 57668 57668 57668 57668 57668 57668 57668 57668 57668 91637 91637 57668 57668 32997 10392 10392 10392 10392 10392 10392 10392 10392 10392 10392 10392 10392 10392 10392 OBOA9 04713 01295 Mfr Part Number CRB20 FXE 15K0 CRB20 FXE 16K5 CRB20 35K7 CRB14FXE 24 3 CRB20 FXE 100E CRB20 FXE 8K06 CRB20 FXE 100E CRB20 FXE 2K00 CRB20 FXE 15K0 CCF50 2F26700F CCF501G200R0F 20 71K5 CRB20FXE 27 4 3329 158 502 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 7 16150 8 DS1210 MC74HC113N LM393P Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1U1020 A1A1U1021 A1A1U1022 A1A1U1023 A1A1U1030 A1A1U1031 A1A1U1032 A1A1U1034 A1A1U1040 A1A1U1041 A1A1U1042 A1A1U1043 1 1 2011 A1A1U2012 A1A1U2021 A1A1U2022 A1A1U2023 A1A1U2024 A1A1U2025 A1A1U2026 A1A1U2027 A1A1U2030 A1A1U2031 A1A1U2032 A1A1U2033 A1A1U2034 A1A1U2036 A1A1U2037 A1A1U2040 A1A1U2041 A1A1U2042 1502B MTDR Service Manual Tektronix Part Number 670 9285 XX 156 2473 00 156 2473 00 156 2583 00 156 2587 00 156 1397 00 156 2392 00 156 1994 00 156 0991 02 156 3058 00 156
134. M5Y5CA C114C224M5Y5CA KME35VB471M10X20LL KME35VB471M10X20LL C114C224M5Y5CA C114C224M5Y5CA 114 224 5 66506 032 082 3644 5510 8 21 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A2 A2PS2030 A2Q1020 A2Q1030 A2Q2020 A2R1010 A2R1011 A2R1012 A2R1013 A2R 1018 A2R 1020 A2R1021 A2R 1022 A2R 1023 A2R 1024 A2R 1025 A2R 1026 A2R 1027 A2R1030 A2R1031 A2R2010 A2R2020 A2R2021 A2R2022 A2R2024 A2R2030 A2R2031 A2R2032 A2R2034 A2R2035 A2R2036 A2R2037 0 22 Tektronix Part Number 672 1251 119 2370 00 151 1176 00 151 1176 00 151 1121 01 322 3385 00 321 0816 00 322 3097 00 322 3341 00 311 1337 00 322 3097 00 322 3385 00 311 2400 00 322 3385 00 322 3385 00 322 3385 00 322 3385 00 322 3385 00 322 3385 00 322 3059 00 322 3385 00 322 3001 00 222 3385 00 321 0523 00 311 2400 00 322 3385 00 322 3385 00 322 3341 00 322 3385 00 322 3385 00 222 3385 00 322 3385 00 Discontd Qty Name amp Description CIRCUIT BD ASSY FRONT PANEL Con t CONVERTER DC AC 15V IN 80V AT 400 HZ XSTR PWR MOS P CH 100V 1 0A 0 6 OHM XSTR PWR MOS P CH 100V 1 0A 0 6 OHM XSTR PWR MOS N CH 60V 0 5A 3 0 OHM RES FXD METAL FILM 100K OHM 1 0 2W RES FXD FILM 5K OHM 1 0 125W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD FILM 40 2K OHM 1 0 2W RES NONWW TRMR 25 OHM 0 5W CERMET RES FXD METAL FILM 100 OHM 196 0 2W RES FXD META
135. NIX WITH RESPECT TO THIS PRODUCT IN LIEU OF ANY OTHER WARRANTIES EXPRESSED OR IMPLIED TEKTRONIX AND ITS VENDORS DISCLAIM ANY IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE TEKTRONIX RESPONSIBILITY TO REPAIR OR REPLACE DEFECTIVE PRODUCTS IS THE SOLE AND EXCLUSIVE REMEDY PROVIDED TO THE CUSTOMER FOR BREACH OF THIS WARRANTY TEKTRONIX AND ITS VENDORS WILL NOT BE LIABLE FOR ANY INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES IRRESPECTIVE OF WHETHER TEKTRONIX OR THE VENDOR HAS ADVANCE NOTICE OF THE POSSIBILITY OF SUCH DAMAGES Table of Contents In iii T DES OE E RUE US 320 viii General Safety SUIMDmWary aoe Ed IX Service Safety SUDO de dus General Information Xili Installation and Repacking Operating Instructions 1 1 1 1 Preparing to Use the 15028 a 1 4 gr od es es 1 5 Front Patiel Controls a See oh eA d 1 5 Menu SCICCUONS L 1 7 i curs MEM 1 10 Cable Tes E PEOCEQUEE uu cur bode tees rade ae kk age SUERTE 1 12
136. NTER COURSE DELAY COUNTER DRIVER STOBE FINE DELAY COUNTER RAMP TRIGGER EXPANDED RAMP GENERATOR EXPANDED SAMPLER STROBE 5 18 a PROGRAMMED DELAY c gt 400 ns gt 3 bit gt prgm delay e 14 BITDAC OUTPUT Y A g Figure 5 10 Combined Effects of Time Delay At the end of the coarse delay the rising edge of this signal enables the fine delay d which produces a single ramp trigger pulse after the programmed delay This pulse is shown expanded in waveform e The ramp generator waveform f also shown expanded has a linear voltage ramp beginning on the falling edge of the trigger This voltage is compared to the voltage from the timebase DAC such that when the ramp exceeds the DAC voltage the sampler strobe e falls This falling edge is used as the sampler strobe for video sampling At the beginning of each sweep the zero distance reference is calibrated to the front panel connector and the length of the analog ramp to 50 ns Zero distance reference is calibrated by setting the digital and analog timebase for zero delay Then the processor adjusts the driver delay so as to sample at the 10 point of the pulse The ramp is calibrated by removing 50 ns of delay one 50 ns clock cycle from the sample trigger and then reinserting it with the analog dela
137. OLAR PNP 40V 200MA 250MHZ AMP XSTR PWR MOS P CH 100V 1 0A 0 6 OHM XSTR PWR MOS P CH 100V 1 0A 0 6 OHM Mfr Code 31433 0 985 21847 21847 21847 21847 21847 01295 21847 21847 21847 21847 21847 21847 53387 53387 53387 0 R03 0 R03 80009 04713 01295 03508 01295 03508 04713 04713 Mfr Part Number C114C224M5Y5CA CEUST1E100 A2X600 A2X600 A2X600 A2X600 A2X600 1N4152R A2X600 A2X1582 A2X1582 A2X600 A2X600 A2X600 3593 5002 3598 6002 3592 5002 120 1606 00 108 0509 01 149 0057 00 IRFD9120 SKA3703 X39H3162 SKA3703 X39H3162 IRFD9120 IRFD9120 1502B MTDR Service Manual Replaceable Electrical Parts Replaceable Parts List Cont Assy Number 1 1 A1A1Q3030 A1A1Q4030 1 104031 1 104040 1 105020 1 105030 1 105031 1 105032 1 106020 1 107020 1 10 7021 A1A1Q7030 A1A1Q8020 A1A1Q9010 A1A1Q9020 A1A1Q9021 A1A1R1010 A1A1R1011 A1A1R1012 A1A1R1013 A1A1R1014 A1A1R1015 A1A1R1016 A1A1R1020 A1A1R1021 A1A1R1022 A1A1R 1023 Tektronix Part Number 670 9285 151 0276 01 151 1078 00 151 0441 00 151 0271 00 151 0353 00 151 0232 00 151 0308 00 151 0441 00 151 1012 00 151 0354 00 151 0261 00 151 0271 00 151 0441 00 151 0139 00 151 0441 00 151 0139 00 151 0271 00 151 0353 00 151 0232 00 151 0308 00 151 0211 00 322 3162 00 322 3289 00 322 3289 00 322 3289 00 322 3385 00 322 3318 00 322 3097 00 322 3289
138. PL INSULATOR FISHPAPER 3 6 X 3 0 INSULATOR FISHPAPER 3 6 X 3 0 DISPLAY MODULE SEE A5 REPL NUT SLFLKG HEX 6 32 X 0 312 HEX SHIELD ELEC EMI BOTTOM SHIELD ELEC EMI BOTTOM SCR ASSEM WSHR 4 40 X 0 25 PNH POZ SPACER POST 0 605 L 4 40 HEX WHSR LOCK 0 115 ID SPLIT WSHR FLAT 0 125 X 0 25 OD X 0 022 MKR IDENT MKD EMI SHIELD INSTRU NOT ILLUSTRATED AT THIS TIME ON OFF SHAFT ASSEMBLY SHAFT ASSEMBLY INCLUDES O RING 0 031 X 0 93 OD Mfr Code 80009 0 4 1 0 4 1 80009 2K262 2K262 53217 2K262 2K262 0 RZ5 28334 80009 10189 22526 80009 80009 22599 0 260 0 260 01536 80009 OKBO1 12327 0 472 TK2545 Mfr Part Number 213 1089 00 386 5307 00 386 5307 01 614 0389 01 R 10460 R 10460 87 90279 R 10460 348 0976 00 348 1144 00 348 0920 00 331 0502 00 551 060545 0X 65474 006 342 0731 00 342 0731 01 22NM 62 331 2193 02 331 2193 04 821 01655 024 129 1092 00 ORD BY DESCR ORD BY DESCR 334 8135 00 650 3714 00 10 9 Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont Fig amp Index Number FIG 10 2 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 550 10 10 Tektronix Part Number 220 0961 00 213 0004 00 213 0966 00 354 0687 00 211 0005 00 210 0803 00 210 0851 00 105 0954 00 105 0954 01 210 1421 00 384 1674 00 384 1674 01 211 0007 00 210 1092 00 650 3699 00 212 0001 00 210 0008
139. PUT on 1 17 Operating Instructions 1 18 How to Store the Waveform Using VIEW STORE UA nO 0 F F 0 F Figure 1 16 Display with VIEW INPUT Turned Off When pushed the STORE button puts the current waveform being displayed into memory If already stored pushing STORE again will erase the stored waveform The front panel control settings and the menu accessed settings are also stored They are accessed under View Stored Waveform Settings in the first level of the menu 3 0000 Figure 1 17 Display of a Stored Waveform The VIEW STORE button when pushed on displays the waveform stored in the memory as a dotted line If there is no waveform in memory a message appears on the LCD informing you of this E E CN ll Figure 1 18 Display of a Stored Waveform 1502B MTDR Service Manual Operating Instructions Using VIEW DIFF 1502B MTDR Service Manual When pushed on the VIEW DIFF button displays the difference between the current waveform and the stored waveform as a dotted line If no waveform has been stored a message will appear The difference waveform is made by subtracting each point in the stored waveform from each point in the current waveform NOTE If the two waveforms are identical e g if STORE is pushed and VIEW DIFF is immediately pushed the difference would be zero Therefore you would see the dif
140. R PWR MOS N CH 60V 0 8A 0 8 OHM RES FXD 0 1 OHM 596 1 0W RES FXD METAL FILM 1K OHM 196 0 2W RES FXD METAL FILM 2K OHM 196 0 2W RES FXD FILM 16 2K OHM 1 0 2W RES FXD METAL FILM 3 32K OHM 1 0 2W RES FXD FILM 2 49K OHM 1 0 2W RES FXD FILM 13 3K OHM 1 0 125W RES FXD FILM 14K OHM 1 0 2W RES FXD METAL FILM 3 32K OHM 1 0 2W RES FXD METAL FILM 20K OHM 1 0 2W RES FXD FILM 237 OHM 1 0 125W RES FXD FILM 909 OHM 1 0 2W Mfr Code 80009 80009 58050 54937 54937 04713 04713 04713 04713 04713 04713 03508 04713 04713 04713 04713 56637 57668 57668 91637 91637 57668 80009 57668 91637 57668 80009 57668 Mfr Part Number 131 4177 00 131 3445 00 082 3644 5510 500 3990 500 3990 IRFD9120 IRFD9120 2N4401 2N4401 IRFD9120 IRFD9120 X39H3162 MPS2369A MTP12N10E IRFD113 IRFD113 BW10 10HM CRB20FXE 1K00 CRB20 FXE 2K00 CCF50 2 G16201FT CCF50 1 G3200F CRB20 FXE 2K49 321 0301 00 CRB20 FXE 14K0 CCF50 1 G3200F CRB20 FXE 20K0 321 0133 00 CRB20 FXE 909E 8 27 Replaceable Electrical Parts Replaceable Parts List Cont Assy Number A3M A3A1R1021 A3A1R1022 A3A1R1023 A3A1R1024 A3A1R1025 A3A1R1026 A3A1R1030 A3A1R2010 A3A1R2011 A3A1R2012 A3A1R2013 A3A1R2014 A3A1R2015 A3A1R2016 A3A1R2017 A3A1R2018 A3A1R2020 A3A1R2021 A3A1R2022 A3A1R2023 A3A1R2024 A3A1R2025 A3A1R2026 A3A1R2027 A3A1R2030 A3A1R2031 A3A1R2032 8 28 Tektronix Part Number 670 9286 XX 321
141. ROUND SYMBOL 22670 BY DESCR 10 14 1502B MTDR Service Manual Replaceable Mechanical Parts Replaceable Mechanical Parts List Cont Fig amp Index Number FIG 10 4 1502B MTDR Service Manual Tektronix Part Number 016 0813 00 016 0813 01 214 1573 00 210 1160 00 333 1990 00 333 1990 02 334 6867 00 211 0198 00 213 0267 00 348 0432 00 348 1143 00 348 1143 01 337 2762 00 211 0008 00 343 0349 01 210 0406 00 211 0194 00 210 0054 00 361 0776 00 214 2344 00 136 0352 00 386 2435 00 146 0065 00 214 2343 00 Serial R010100 B021135 R010100 B021135 R010100 B021135 B035825 Serial No Discont d B021134 B021134 B021134 B035824 Qty Name amp Description A Aa Aa A MO A N 03 BTRY ASSY STORE 1 2V 2000M AH 0 2C BTRY ASSY STORE 1 2V 2000MAH 0 2C C CELL 9 THUMBSCREW 6 32 X 0 656 0 312 SST WSHR FLAT 0 1291D X 0 2500 X 0 031 TEFLON PANEL FRONT UNFINISHED PANEL FRONT BATTERY SET LABEL MARKED BATTERY STORAGE TEMP SCR MACH 4 40 X 0 438 PNH POZ SCR TPG 4 24 X 0 375 PAN HD POZ GASKET FRONT PANEL GASKET COND ELASTOMER W AL GASKET BATTERY 0 062 THK X 2 600 X 2 600 SHIELD FUSE AL SCR MACH 4 40 X 0 25 PNH POZ CLAMP BATTERY RTNG W HOLES DELRIN NUT PLAIN HEX 4 40 X 0 188 SCR MACH 4 40 X
142. Service Manual Tektronix 7 1502 Metallic Time Domain Reflectometer 070 6267 04 This document applies for firmware version 5 02 and above Warning The servicing instructions are for use by qualified personnel only To avoid personal injury do not perform any servicing unless you are qualified to do so Refertothe Safety Summary priorto performing service First Printing June 1996 Revised February 1998 Instrument Serial Numbers Each instrument manufactured by Tektronix has a serial number on a panel insert or tag or stamped on the chassis The first letter in the serial number designates the country of manufacture The last five digits of the serial number are assigned sequentially and are unique to each instrument Those manufactured in the United States of America have six unique digits The country of manufacture is identified as follows 010000 Inc Beaverton Oregon U S A 200000 United Kingdom Ltd London England J300000 Sony Tektronix Japan H700000 Tektronix Holland NV Heerenveen The Netherlands Instruments manufactured for Tektronix by external vendors outside the United States are assigned a two digit alpha code to identify the country of manufacture e g JP for Japan HL for Honk Kong IL for Israel etc Tektronix Inc PO Box 500 Beaverton Oregon 97077 USA Printed in U S A Copyright Tektronix Inc 1998 All rights reserved Tektronix product
143. TROLS INC SPECTROL DIV GENERAL ELECTRIC CO SEMI CONDUCTOR PRODUCTS DEPT AVX CERAMICS DIV OF AVX CORP ITW SWITCHES DIV OF ILLINOIS TOOL WORKS INC MOTOROLA INC SEMICONDUCTOR PRODUCTS SECTOR TRW INC TRW IRC FIXED RESISTORS BURLINGTON BURNDY CORP DALLAS SEMICONDUCTOR CORP MARCON AMERICA CORP ZMAN MAGNETICS INC TOSHIBA AMERICA INC ELECTRONICS COMPONENTS DIV GENERAL STAPLE CO INC CLAROSTAT MFG CO INC MICROSEMI CORP SCOTTSDALE UNITRODE CORP SENSITRON SEMICONDUCTOR DIV OF RSM ELECTRON POWER INC ITT SEMICONDUCTORS DIV MICROSEMI CORP GENERAL INSTRUMENT CORP DISCRETE SEMI CONDUCTOR DIV 1502B MTDR Service Manual Address JOHN ST 12015 2ND ST 13500 N CENTRAL EXPY PO BOX 655012 195 MCGREGOR ST 17070 E GALE AVE P BOX 1220 W GENESEE ST 19TH AVE SOUTH P O BOX 867 6615 W IRVING PARK RD 5005 E MCDOWELL RD 2850 MT PLEASANT AVE RICHARDS AVE 4350 BELTWOOD PKWY SOUTH 3PEARL COURT 1633 S 180th 2692 DOW AVE 59 12 37TH ST LOWER WASHINGTON ST 8700 E THOMAS RD P BOX 1390 5 FORBES RD 221 W INDUSTRY COURT 2830 S FAIRVIEW ST 600 W J OHN ST City State Zip Code HUDSON FALLS NY 12839 MILWAUKEE WI 53204 2410 DALLAS TX 75265 MANCHESTER NH 03102 3731 CITY OF INDUSTRY CA 91749 AUBURN NY 13021 MYRTLE BEACH SC 29577 CHICAGO IL 60634 2410 PHOENIX AZ 85008 4229 BURLINGTON IA 52601 NORWALK CT 06852 DALLAS TX 75244 ALLENDALE NJ 07401 KENT WA 98032 TUSTIN CA 92680 WOODS
144. TRONIX Bescheinigung des Herstellers Importeurs Hiermit wird bescheinigt da das Tektronix 1502B Metallic TDR bereinstimmung mit den Bertimmungen der Amtsblatt Verf gung 1046 1984 funkentst rt ist Der Deutschen Bundespost wurde das Inverkehrbringen dieses Ger tes angezeigt und die Bereschtigung zur Uberprufung der Serie auf Einhalten der Bestimmungen eingera mt TEKTRONIX NOTICE to the user operator The German Postal Service requires that this equipment when used in atest setup may only be operated ifthe requirements of Postal Regulation Vfg 1046 1984 Par 2 Sect 1 7 1 are complied with HINWEIS f r den Benutzer Betriber Dieses Ger t darf in Mefaufbauten nur betrieben werden wenn die Voraussetzungen des Par 2 Ziff 1 7 1 der Vfg 1046 1984 eingehalten werden NOTICE to the user operator The German Postal Service requires that systems assembled by the operator user of this instrument must also comply with Postal Regulation Vfg 243 1991 Par 2 Sect 1 HINWEIS f r den Benutzer Betreiber Die vom Betreiber zusammengestellte Anlage innerhalb derer dieses Ger t eingesetzt wird muB ebenfalls den Voraussetzungen nach Par 2 Ziff 1 der Vfg 243 1991 gen gen WARRANTY Tektronix warrants that this product will be free from defects in materials and workmanship for a period of one 1 year from the date of shipment If any such product proves defective during this warranty period Tektronix at its
145. The LCD drive voltage compensation circuitry adjusts the drive voltage contrast to assure a constant display contrast within the operating temperature range of the instrument The display thermistor is attached to the LCD and forms the sensor in the display thermistor divider circuit Its output 1s a voltage related to the display temperature This voltage is read by the processor through the analog to digital converter U2023 The processor uses this voltage value to determine a drive voltage This is sent to digital to analog converter U2021 via the data bus The output of the DAC is amplified to op amp U2010A and applied as the LCD drive voltage As the temperature of the display thermistor divider voltage changes the processor modifies the drive voltage via the DAC In this manner the drive voltage is compensated due to variations in display temperature Trimmer potentiometer R1011 is used to offset the drive voltage produced by U2010A to compensate for variations in display cells and thermistors 1502B MTDR Service Manual Circuit Descriptions Display Module Introduction 1502B MTDR Service Manual The display module consists of the following LCD Cell Row Driver Controller Board and Column Driver Board Electroluminescent Backlight Indium Tin Oxide ITO Heater Mechanical frame which supports the above subassemblies The display module function 15 to take bit pattern data generated by the instrument internal electronics a
146. XD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI 1000PF 20 DIP STYLE CAP FXD CER 1 1000 2090 DIP STYLE CAP FXD CER DI 1000PF 20 DIP STYLE CAP FXD CER DI 1000PF 20 DIP STYLE CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI 1000PF 20 DIP STYLE CAP FXD CER DI 1000PF 20 DIP STYLE CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD ELCTLT 470UF 50 20 35V AL CAP FXD ELCTLT 470UF 50 20 35V AL CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CAP FXD CER DI MLC 0 22UF 20 50V ZRU CONN HDR PCB MALE STR 2 X 25 0 1 CTR CONN HDR PCB MALE STR 1 X 36 0 1 CTR Mfr Code 18796 31433 31433 31433 31433 55680 55680 31433 31433 04222 04222 04222 04222 31433 04222 04222 31433 31433 31433 31433 31433 31433 31433 1W344 1W344 31433 31433 31433 22526 58050 Mfr Part Number RPE112NPO102K200V C322C102 2G5CA 114 224 5 114 224 5 C114C224M5Y5CA UVX1H100MAA UVX1H100MAA C114C 224M5Y5CA C114C 224M5Y5CA MD015C102MAA MD015C102MAA MD015C102MAA MD015C102MAA C114C 224M5Y5CA MD015C102MAA MD015C102MAA C114C 224M5Y5CA C114C 224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224M5Y5CA C114C224
147. able and Select Signal space 5 9 EPROM 5 9 General 5 7 Interrupt Logic 5 10 Memory 5 9 Microprocessor 5 8 Non volatile RAM Space 5 9 Program Memory 5 9 RAM 5 9 Pulse Generator Sampler Block Diagram 5 24 System Block Diagram 5 2 Timebase Analog 5 20 Block Diagram 5 16 Calibration of Delay Diagram 5 19 Control Diagram 5 17 Digital 5 20 General 5 15 Time Delay Diagram 5 18 Video Processor General 5 13 Output Scope Waveform 5 15 summing Amplifier 5 14 Vertical Position DAC 5 14 Video ADC 5 15 Video Amplifier 5 14 Waveform Accumulation Diagram 5 3 Connectors BNC 4 3 Index 2 BNC to Alligator 4 3 BNC to Banana 4 3 BNC to Binding Post 4 3 BNC to F Type 4 3 BNC to GR 4 3 BNC to Hook Tips 4 3 BNC to N Type 4 3 BNC to UHE 4 3 Controls Cable Connector 1 5 Distance Division 1 6 Front Panel 1 4 1 5 Horizontal Position 1 6 Menu Button 1 6 Noise Filter 1 5 Power 1 6 Store Button 1 7 Velocity of Propagation 1 6 Vertical Position 1 6 Vertical Scale 1 6 View Difference Button 1 6 View Input Button 1 6 View Store Button 1 6 D Depth Spec 3 4 Diagrams Component Locator Driver Sampler Board 9 30 Front Panel Board 9 25 Main Board 9 15 Power Supply Board 9 28 Exploded Views Assemblies 10 18 Battery Pack 10 20 Cabinet 10 17 Frame 10 18 Front Panel Controls 10 18 Power Supply 10 19
148. ady Metric Instruments 1502B MTDR Service Manual The purpose of this procedure is to assure that the instrument is in good working condition and should be performed on an instrument that has been serviced or repaired as well as at regular intervals This procedure is not intended to familiarize you with the instrument If you are not experienced with this instrument you should read the Operation chapter of this manual before going on with these checks If the instrument fails any of these tests it should be calibrated or otherwise serviced Many failure modes affect only some functions of the instrument Equipment Tek Part Number 500 precision terminator 011 0123 00 3 ft precision coaxial cable 012 1350 00 Disconnect any cables from the front panel CABLE connector Connect the instrument to a suitable power source a fully charged optional battery pack or AC line source If you are using AC power make sure the fuse and power selector switch on the rear panel are correct for the voltage you are using 115 VAC requires a different fuse than 230 VAC Option 05 metric instruments default to m div instead of ft div You can change this in the Setup menu or you may use the metric numbers provided To change the readings to ft div press the MENU button Scroll down to Distance Div is m div 6 1 Calibration Display Module Check 6 2 Liquid Crystal Display A and press MENU again That menu line will change to
149. ain Board 7 10 15028 MTDR Service Manual Contents 1502B MTDR Service Manual Figure 7 9 Figure 7 10 Figure 7 11 Figure 7 12 Figure 7 13 Figure 7 14 Figure 7 15 Figure 7 16 Figure 7 17 Figure 7 18 Figure 7 19 Figure 9 Figure 9 2 Figure 9 3 Figure 9 4 Figure 9 5 Figure 10 1 Figure 10 2 Figure 10 3 Figure 10 4 Display Module Front Panel Board Screw Locations 7 12 Display Module Front Panel Board Showing Hex Nuts 7 13 Location of Default Jumper on Front Panel Board 7 13 Default Jumper POSICODS 22s vas 9x zur 7 14 Main Board TP1041 and 3040 7 15 Main Board TP3041 and TP4040 7 15 Main Board 6010 and TP7010 7 16 Main Board TP9011 TP9041 7 16 Front Panel CABLE Connector 7 16 Installing Top and Bottom EMI Shields 7 21 Installing the Case Cover Over the Chassis 7 22 Special Schematic Symbols 9 3 Component Locator Main Board 9 15 Schematics Main Board 9 16 24 Component Locator Front Panel Board 9 25 Schematics Front Panel 9 26 27 Component Locator Power Supply Board 9 28 Schematics Power Supply 9 29 Component Locator Driver Sampler Board
150. ained in the display module An indium tin oxide ITO heater warms the display during cold temperatures A temperature sensor attached to the display provides display temperature data to the heater and drive voltage circuitry see Front Panel text in this chapter An electroluminescent backlight provides illumination in low light conditions The LCD cell provided in the 1502B uses an advanced technology known as Superbirefringent Effect SBE to obtain greatly improved contrast and viewing angle over conventional LCD cells The function of the LCD module is to receive bit pattern data from the CPU and display it First the processor generates a 4k X 8 bit pattern image in its own memory It then writes this bit pattern via the data bus to the display memory U1040 in the form of a block transfer The bit pattern is mapped in the display memory and later on the LCD cell Second the LCD controller 02040 reads the bit pattern from the display RAM formats it and sends it to the column drivers Last the column drivers and the row drivers generate select and non select voltages based on the timing control and data signals received from the controller These voltages are applied to the LCD cell matrix turning off and on pixels that match the bit pattern in the display memory The pattern of pixels form the image on the display The cell is physically composed of two planes of glass two polarizers a matrix of transparent electrodes and
151. anel and to find fault DUE contrast ROIA RAM ROM Diagnosis r per Adjustment Procedure 99 function modules Tare RANM ROM Front Panel diagnostic diagnostic wont run or passed diagnostic failed Check power supply Fix indicated board Check display Check processor Check front module or cabling system system panel board 21 1 Maintenance Waveform off top or bottom display or wrong height at line Ios Check pulse strobe TP9011 on main board with scope Bad Check trigger TP3040 on main board with scope Good p Bad Yes Y Good Check video TP9041 Good Check signal on main board CABLE with scope with scope atall pulse widths Bad Y Check sample strobe 7010 n main por board with scope Good Y Check ramp trigger 3041 on main board with scope Good Check video amp Check sampler on Check analog delay front end board on main board 7 18 Check digital delay Check pulser on on main board front end board 1502B MTDR Service Manual Maintenance Leading edge not at N N 3 1502B MTDR Service Manual zero wrong length No or with discontinuities Yes Y Check chart recorder or other extra function mo
152. ble through the rear panel of the case 1 Unscrew the fuse cover and remove C REMOVE O REMOVE CAP TO CAP 19 Q Figure 7 1 Location of Voltage Selector and Fuse Holder on Rear Panel 1502B MTDR Service Manual Maintenance Removal of Case and EMI Shields Checking Desiccant Cartridge SN lt B037562 only 1502B MTDR Service Manual D m Use a straight blade screwdriver to remove the fuse holder Check the voltage selector for proper voltage setting If the instrument voltage selector is set for 115 VAC replace the fuse with a 0 3 A fuse Tek P N 159 0029 00 If the voltage selector is set for 230 replace the fuse with 0 15 A fuse Tek P N 159 0054 00 Replace the fuse holder Replace the access cover Remove the instrument front cover If installed remove the battery pack from the back of the instrument If installed remove the chart recorder or other device from the option port Loosen the four screws on the back of the case and set the instrument face up on a flat surface Swing the handle out of the way of the front panel Break the chassis seal by pushing downward with both hands on the handle pivots on each side of the case Grasp the case with one hand and tilt the chassis out with the other Lift by grasping the outside perimeter of the front panel CAUTION Do
153. ce is shown in Figure 5 5 The processor system provides all the data and control for the interface Data Address and Control lines are all buffered for increased drive The power to the option port is switchable to reduce power consumption if necessary The other outputs are available for control and protocol purposes SWITCHED SUPPLY POWER CONTROLLER lt DATA ADDRESS y BUFFERS POWER CONTROL OUTPUT LATCH Figure 5 5 Option Port Interface Block Diagram The 16 VDC and 5 VDC power outputs to the option port are switched supplies controlled by the microprocessor system CS14 and CS15 are used to set and clear flip flop U1011B This feeds comparators U1012A and U1012B The positive input to the comparators is set at 2 5 volts so the CMOS flip flop will drive the negative terminals above and below that voltage level The comparators are powered with a 16 VDC and a 12 VDC source to give a good output swing in controlling the FET switches The output of U1012A controls the 16 VDC switch and is pulled up via a 20 resistor R2011 The output is also passed through two 100 resistors R2012 and R2013 to prevent the FETS from being over driven Two parallel FETs Q2011 and Q2012 control the supply To reduce the instantaneous draw from the instrument supply when first turning
154. cks on the module side panels If the board or the capacitor binds on either the nut blocks or the chassis side panel screw remove the nut blocks Remove the power supply module and circuit board as per previous procedures Remove the three screws holding the side panel on the power supply module Remove the side panel This will provide access to the transformer Unsolder the six wires attached to the power transformer Unsolder the varistor R101 from lugs 4 and 5 Remove the two screws and lock washers holding the power transformer to the chassis Lift out the transformer NOTE When reassembling add a small amount of LocTite to the two transformer mounting screws in step 6 1 Remove the power supply module circuit board and transformer per previous procedures 1502B MTDR Service Manual Maintenance 2 Unsolder the three wires on the filter unit 3 Remove the two screws and the spacer holding the receptacle 4 Remove the filter unit from the rear of the module Removing the Fuse Holder and Voltage Selector procedures Power Conductor Unsolder all four wires from the voltage selector switch Unsolder the two wires from the fuse holder Unscrew the hold down nuts from both units Remove both units from the rear of the module Remove the power supply module circuit board and transformer per previous Color Code Conductor Color Alternate Color Ungrounded line Brown
155. cquired at the CABLE connector This function is useful to stop INPUT displaying a current waveform to avoid confusion when looking at a stored waveform This function defaults to ON when the instrument is powered up view 11 VIEW STORE When pushed momentarily this button toggles the display of STORE the stored waveform VIEW 12 VIEW DIFF When pushed momentarily this button toggles the display of the DIFF current waveform minus the stored waveform and shows the difference between them 1 6 1502B MTDR Service Manual Operating Instructions STORE gt Menu Selections Main Menu 1502B MTDR Service Manual 13 STORE When pushed momentarily the waveform currently displayed will be stored in the instrument memory If a waveform is already stored pushing this button will erase it The settings of the stored waveform are available from the first level menu under View Stored Waveform Settings There are several layers of menu as explained below The Main Menu is entered by pushing the MENU button on the front panel Return to Normal Operations puts the instrument into normal operation mode Help with Instrument Controls explains the operation of each control When a control or switch is adjusted or pushed a brief explanation appears on the LCD Cable Information has these choices a Help with Cables gives a brief explanation of cable parameters b V
156. current to junction FET Q5031 The ramp voltage is AC coupled to voltage comparator Q7021 by C7030 to remove the DC offset voltage developed in the preceding circuits A small negative DC voltage of approximately 200 mV is added by voltage divider R7032 and R7025 to hold the voltage comparator off between pulses 5 21 Circuit Descriptions Voltage comparator 07021 is biased at 2 mA by dual transistor Q5020 During the linearly rising ramp voltage it compares the ramp to a programmed DC sample reference voltage produced by the timebase DAC circuit When the ramp reaches the sample reference value Q7021A rapidly turns on to produce a negative going signal across R7024 This pulse is coupled through C7022 and R7021 to turn on 06020 providing a positive pulse to the base of 07020 The negative going sampler strobe coming from Q7020 is supplied to the sampler and to TP7010 Timebase DAC 04020 and amplifier 05010 inverts and multiplies by the 14 bit digital word loaded by the processor It is filtered for noise by R7026 and C5023 and connected to comparator Q7021 through R7027 to set the analog delay 0 to 50 ns To calibrate the analog delay to 50 ns the processor sets IR2 IR2 high and loads a new 12 bit word in latches 03021 and 03022 max 1 bit change per sweep with chip selects and CS12 DAC U3023 multiplies the reference current 1 mA set by R3020 by the digital word from the latches The DAC output current and t
157. d All Vp settings should be set for the cable under test not the supplied jumper cable Dielectric Probable Vp Jelly Filled 64 Polyethylene PIC PE or SPE 66 PTFE Teflon 9 or TFE 70 Pulp Insulation AA Foam or Cellular PE FPE 18 Semi solid PE SSPE 84 Air helical spacers 98 15028 MTDR Service Manual Operating Instructions Finding an Unknown Vp 1502B MTDR Service Manual 1 Obtain a known length of cable of the exact type you wish to test Attach the cable to the CABLE connector on the front panel 2 Pull POWER on 3 Turn the DIST DIV to an appropriate setting e g if trying to find the Vp of a three foot cable turn the DIST DIV to 1 ft div 4 Turn the 4 POSITION control until the distance reading is the same as known length of this cable 5 Turn the Vp controls until the cursor 1s resting on the rising portion of the reflected pulse The Vp controls of the instrument are now set to the Vp of the cable The following three illustrations show settings too low too high and correct for a sample three foot cable 3 0008 3 000 ft a Figure 1 6 Vp Set at 99 Cursor Less Than Reflected Pulse Set Too High Operating Instructions LoT uq O aa F Figure 1 7 Vp Set at 66 Cursor at Reflected Pulse Set Correctly Cable Test Procedure Distance to the Fault Be sure to read the pre
158. d in the Options and Accessories chapter of this manual Terminology used in this manual is in accordance with industry practice Abbreviations are in accordance with ANSI Y 1 1 19722 with exceptions and additions explained in parentheses in the text Graphic symbology is based on ANSI Y32 2 1975 Logic symbology is based on ANSI 32 14 1973 and manufacturer s data books or sheets A copy of ANSI standards may be obtained from the Institute of Electrical and Electronic Engineers 345 47th Street New York NY 10017 Changes that involve manual corrections and or additional data will be incorporated into the text and that page will show a revision date on the inside bottom edge History information is included in any diagrams in gray xiii General Information Installation and Repacking Power Source and Power XIV Unpacking and Inltial Inspection Requirements Repacking for Shipment Before unpacking 1502B from its shipping container or carton inspect for signs of external damage If the carton 15 damaged notify the carrier The shipping carton contains the basic instrument and its standard accessories Refer to the replaceable parts list in the Service Manual for a complete listing If the contents of the shipping container are incomplete if there is mechanical damage or defect or if the instrument does not meet operational check requirements contact your local Tektronix Field Office or representative If the shi
159. des affect only some of the instrument functions Item Tektronix Part Number 500 precision terminator 011 0123 00 3 foot precision coaxial cable 012 1350 00 Disconnect any cables from front panel CABLE Connect the Instrument to a suitable power source a fully charged optional battery pack or AC line source If you are using AC power make sure the fuse and power switch are correct for the voltage you are using 115 VAC requires a different fuse than 230 VAC Pull the POWER switch on the front panel If a message does not appear on the display within a second ortwo turn the instrument off There are some failure modes that could permanently damage or ruin the LCD if the power is left on for more than a minute or so Option 05 instruments default to metric however you can change the metric scale to ft div in the Setup Menu or use the metric numbers provided To change the readings press the MENU button Using the POSITION control scroll down to Setup Menu and press MENU again Scroll down to Distance Div is m div and press MENU again This will change to ft div Press the MENU button repeatedly to return to normal operation mode If the instrument power is turned off these checks must be repeated again when the instrument is powered on again Operator Performance Checks Up Set the 1502B front panel controls NOISE FILTER 1 avg VERT SCALE no adjustment DIST DIV ft div 0 25 m Vp 66
160. detect and display the impedance characteristics of a metallic cable from one end of the cable This is accomplished by applying a rapidly rising step to the cable and monitoring the resulting voltage over a period of time If the cable has a known propagation velocity the time delay to a particular reflection can be interpreted in cable distance Amplitude of the reflected voltage is a function of the cable impedance and the impedance of the termination relative to the cable leading to it The amplitude can be interpreted in rho or dB Rho p is a convenient impedance function defined as the voltage reflection coefficient It is the ratio between the incident step and the reflected step For the simple case of a cable with a resistive load RL Zo RL Zo Where 15 the load impedance Zo is the characteristic impedance The 1502B instrument is comprised of several subsections as shown in the block diagram Figure 5 1 These are organized as a processor system which controls several peripheral circuits to achieve overall instrument performance The processor system reads the front panel control settings to determine the cable information that you selected for viewing Distance settings are converted to equivalent time values and loaded into the timebase circuits The timebase generates repetitive strobe signals to trigger the driver sampler circuits Pulse strobes cause a step to be applied to the cable under test Sample strob
161. ds to Column 1 and seg 0 corresponds to Column 64 m FOUT Output from the enable flip flop Supply Voltages include the following 5 VDC supply voltage for logic and select drive voltage non select voltage V4 non select voltage Vr cp Select voltage GND return for 5 VDC To perform its function the column driver shift registers are filled with data by receiving data XSCL and from the controller LP then latches the contents of the shift registers into the latches The level shifter translates the logical Is and Os in the latch into select and non select voltages according to FR see table FR Bit X Latch Column X Output 0 0 V4 0 1 1 0 V3 1 1 5 VDC The pixels selected by both the column drivers and the row driver are turned on all others are off The process of filling the column drivers is repeated every LP 1 for every addressed row until all lines in both screen halves have been refreshed One frame is thus complete and the entire process 15 repeated 1502B MTDR Service Manual Circuit Descriptions Display Memory Controller Row Driver Interface 1502B MTDR Service Manual Shift Direction p Xscl D3 D1 D0 Col X Seg
162. dules Check for lt t 4 volts TP4020 and TP4021 on main board Yes Check digital delay on main board No Check analog delay on main board Run Calibration Performance Check 7 19 Maintenance When Else Fails becomes necessary to ship the instrument to an authorized Tektronix Service Center follow the packing instructions as described in Repacking for Shipment on page xiv Control Panel Installation Watertight Seals A Sealing Materials 7 20 prevent moisture and dirt from getting into the 1502B special seals are used around the LCD faceplate options port battery pack port front panel and front panel button boot Removing the front panel button boot or other rubber seals will require special resealing procedures to retain the instrument weathertightness A list of sealants is provided on the next page to aid in reinstallation However we recommend that resealing be done only by an authorized Tektronix Service Center The front panel cover seal should be inspected regularly and replaced every six to eight months depending on the operating environment and use All other seals should be inspected during normal adjustment calibration periods paying special attention to the battery pack port seals front panel case seal and option port seal CAUTION If the case battery pack option port or a front panel control is removed the weathertigh
163. e Instrument returns to normal operation CAUTION This function is used mostly for troubleshooting by qualified technicians It is not recommended that you use the 1502B as a stand alone monitoring device The input circuitry is very sensitive and can be easily damaged by even moderate level signals In this mode the 1502B is acting as a detector only Any pulses detected will not originate from the instrument so any distance readings will be invalid If you are listening to a local area network for example it is possible to detect traffic but not possible to measure the distance to its origin Pulse is Off can be used in conjunction with Max Hold is On 7 Toexit Pulse is Off access the Acquisition Control Menu again turn the pulse back on then repeatedly push MENU until the instrument returns to normal operation The single sweep function will acquire one waveform only and display it 1 Attach a cable to the 1502B front panel CABLE connector Push MENU to access the Main Menu Scroll to Setup Menu and push MENU again Scroll to Acquisition Control Menu and push MENU again Scroll to Single Sweep is Off and push MENU again This will change to Single Sweep is On 6 Repeatedly press MENU until the instrument returns to normal operation 1 27 Operating Instructions 1 28 7 When you are ready to begin sweep push VIEW INPUT A sweep will also be initiated when you change any of the fr
164. e Sweep 1 27 Velocity of Propagation 1 7 View Stored Waveform 1 9 N Noise see also Controls 1 5 O Ohms at Cursor 1 17 Open 1 13 Option Port Cover 4 2 Options xiii 4 1 Battery Pack 03 4 1 Chart Recorder 04 4 1 Chart Recorder 07 4 2 Metric Default 05 4 1 Power Cords 4 2 P Performance Checks 2 1 Aberrations 2 6 Conclusions 2 10 Equipment Required 2 1 Horizontal Scale 2 2 Jitter 2 9 Noise 2 5 Offset Gain 2 6 Risetime 2 8 Sampling Efficiency 2 6 Set Up 2 2 Vertical Position 2 4 Pouch 4 2 Power AC xiv AC Receptacle 1 1 Battery xiii xiv Low Indicator 1 3 Remove Replace 4 1 Battery Pack Care of 1 2 Charging 1 2 Cords 4 2 Safety ix Fuse x 1 1 Fuse Rating 1 2 Requirements xiv safety xi Source xiii Voltage Rating 1 2 Voltage Selector 1 1 Voltages 1 1 Product Description xv Pulse 1 26 R References XIII Reflection Coefficient 1 14 Index 4 Repacking xiv Replaceable Parts Electrical Assemblies 8 6 Driver Sampler Board 8 30 Front Panel Board 8 21 Main Board 8 8 Parts Ordering Information 8 1 Abbreviations 8 1 Comp Numbers 8 1 Descriptions 8 2 List of Assemblies 8 1 Mfg Number 8 2 Mfr Codes 8 1 8 2 8 3 Serial Number 8 2 Tek Number 8 2 Power Supply 8 25 Wire Assemblies 8 36 Mechanical Abbreviations 10 2 Chassis Parts 10 2 Column De
165. e at TP9011 The ramp trigger pulse from the digital timebase is AC coupled by C3040 and R3041 to 04040 Diode CR3031 allows the negative going pulse to pass directly while R3040 limits the input current sue to the re charging of C3040 between pulses The output of Q4040 is held at ground by L5030 between pulses and rises to 6 VDC during the pulse Choke L5030 is center tapped to provide an equal negative going pulse at its undriven end This pulse is fed through C5033 and R4032 to the emitter of Q4031 to obtain positive feedback to Q4040 This forms a one shot circuit with the pulse width determined by C5033 and R4032 The 25 ns ramp trigger pulse is thus stretched to about 80 ns at L5030 Dual transistor 05032 operates as a current source providing a constant 5 mA current which is used to charge C5032 to create a linear voltage ramp Between ramp trigger pulses this current is conducted through CR4032 and L5030 to ground creating a voltage of 0 5 VDC on C5032 The positive one shot pulse from Q4040 turns off CR4032 and directs the charging current to C5032 The negative going pulse from L5030 is connected to C5032 through CR5030 to provide a cancelling effect for the positive pulse being coupled through the capacitance of CR4032 The linear rising voltage pulse from C5032 is buffered by source follower Q5031 and emitter follower Q5030 to provide a low output impedance and prevent loading the ramp Transistor Q7030 provides a constant 2 mA bias
166. e eyes with large amounts of water and seek medical attention immediately If the material comes in contact with the skin wash with soap and water Silica View Window Cartridge Hold down Bracket Figure 7 2 Desiccant Cartridge on Rear of Chassis 1 Loosen the cartridge hold down bracket located on the rear edge of the instrument chassis 2 Remove the cartridge 3 Heat the cartridge in an oven at approximately 350 F until the blue color is restored to the crystals 4 Place the cartridge in an air tight moisture proof container until it is cool 5 When cool replace the cartridge in its brackets 1502B MTDR Service Manual Maintenance 6 Tighten the retaining bracket Removing the Power Supply Module 1 From the Power Supply Board remove the 14 conductor ribbon cable This 15 a keyed connector so polarity is guaranteed upon reinstallation Figure 7 3 5 1 i 4 Y p lt 1 7 gt View of Power Supply Module 1 gt P 6 om 6 End View e AD O
167. e it in the next check NOTE If the instrument does not pass this check refer to the Circuit Descriptions chapter and the Troubleshooting section of the Maintenance chapter of this manual If the instrument fails this check it should not be used for loss or impedance measurements 1 While in the Service Diagnostic Menu select the Offset Gain Diagnostic and follow the directions shown on the display Exit Service Diagnostic Menu Sampling Efficiency Diagnostic Noise Diagnostic Impedance Diagnostic Offset Gain Diagnostic RAM ROM Diagnostics Timebase is Normal Auto Correction Move SPosition to select then push MENU button Figure 6 26 Service Diagnostic Menu NOTE The 48 dB step might fail intermittently If a more accurate reading is desired TP9041 on the Main Board or TP3051 on the Driver Sampler Board must be grounded during the check See the Maintenance chapter for the case and EMI shield removal instructions 2 There are five screens of data presented in this diagnostic The Pass Fail level is 396 for worst case 3 Press MENU once to return to the Service Diagnostic Menu Do not exit from the Service Diagnostic Menu because you will use it in the next check If the instrument fails this check various functions might be affected Without the RAM ROM functions operating correctly it is doubtful you would have gotten this far This check will give you assurance that the RAM ROM circuits are operating
168. e that the new battery is one that 15 supplied or authorized by Tektronix An improper replacement cell could cause irreversible damage to the Main Board circuitry NOTE If the instrument is equipped with Option 06 Ethernet Adapter Board follow the instructions under Option 06 in this chapter There is an illustration in the Replaceable Mechanical Parts chapter showing the Option 06 and Driver Sampler Boards 1 2 Pm gt Remove the two screws and washers holding the cover to the chassis Remove the cover by sliding it toward the center of the instrument When re assembling make sure the cable is placed under the slot provided Disconnect the multi conductor cable from the circuit board Remove the coaxial cable from the circuit board Remove the circuit board from the instrument by sliding it out of the card guides Using a hex wrench disassemble the power switch linkage This disconnects the front panel switch shaft from the linkage block Remove the three multi conductor cables from the Main Board Remove the Driver Sampler Board EMI shield Remove the coaxial cable from the Driver Sampler Board Remove the four corner screws on the instrument front panel Carefully guide the coaxial cable through the Driver Sampler card cage Remove the Front Panel Assembly from the instrument chassis Using the previous procedure remove the Front Panel Assembly from the instrument Remove all knobs 7 11 Main
169. elocity of Propagation Values displays a table of common dielectrics and their Vp values These are nominal values The manufacturer s listed specifications should be used whenever possible c Impedance Values displays impedances of common cables In some cases these values have been rounded off Manufacturer s specifications should be checked for precise values d Finding Unknown Vp Values describes a procedure for finding an unknown Vp Setup Menu controls the manner in which the instrument obtains and displays its test results a Acquisition Control Menu has these choices i Max Hold Is On Off Turn Max Hold on by pushing MENU then STORE In this mode waveforms are accumulated on the display Max Hold can be deactivated by pushing STORE or the mode exited by using the Setup Menu ii Pulse Is On Off Turns the pulse generator off so the 1502B does not send out pulses iii Single Sweep Is On Off This function is much like a still camera it will acquire one waveform and hold it Operating Instructions Ohms at Cursor is On Off When activated the impedance at thee point of the cursor is displayed beneath the distance window on the display Vertical Scale Is dB mp This offers you a choice as to how the vertical gain of the instrument is displayed You may choose decibels or millirho When powered down the instrument will default to millirho when powered back up Distance Div Is ft m Offers you a choice of ho
170. energy will be reflected back when a pulse is sent down the cable The reflected voltage will equal the incident pulse voltage and rho will be 1 If there is a short circuit in the cable nearly all the energy will be delivered back to the instrument through the ground or return conductor instead of being sent to the load The polarity of the reflected pulse will be the opposite of the incident pulse and rho will be 1 If there is no mismatch between the cable and the load almost no energy will be reflected back and rho will be 0 In general a load or fault with higher impedance than the cable will return a rho measurement of 0 to 1 and a load or fault with a lower impedance will return rho measurement of 0 to 1 The scale for rho measurements is determined by the height of the incident pulse A pulse two divisions high means that each division 15 0 5 rho 500 millirho A pulse set to be four divisions high would make each division 0 25 rho 250 millirho Any unwanted electrical energy that interferes with a signal or measurement Most noise is random with respect to the signals sent by the TDR to make a measurement and will appear on the waveform constantly constantly moving up and down on the display The NOISE FILTER control sets how many waveforms will be averaged together to make the waveform displayed Noisy waveforms appear to fluctuate around the real signal Because it is random noise will sometimes add to the real signal and so
171. enever an abnormality 15 found set the cursor at the beginning of the fault and read the distance to the fault on the distance window of the LCD The reflection coefficient is a measure of the impedance change at a point in the cable It 1s the ratio of the signal reflected back from a point divided by the signal going into that point It is designated by the Greek letter p and is written in this manual as rho The 1502B measures the reflection coefficient in millirho thousandths of a rho To measure a reflection adjust VERT SCALE to make the reflection one division high Read the reflection coefficient directly off the display above the VERT 1502B MTDR Service Manual Operating Instructions Return Loss Measurements 1502B MTDR Service Manual SCALE control For reflections that are greater than 500 mp div adjust VERT SCALE for a reflection that is two divisions high and multiply the VERT SCALE reading by two ae 00008 Figure 1 13 Reflection Adjusted to One Division in Height In an ideal transmission system with no changes in impedance there will be no reflections so rho is equal to zero A good cable that is terminated in its characteristic impedance is close to ideal and will appear as a flat line on the 1502B display Small impedance changes like those from a connector might have reflections from 10 to 100 mo If rho is positive it indicates an impedance higher than that of the cable before the reflecti
172. ents 1502B MTDR Service Manual 9 5 Diagrams A1 MAIN CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION CIRCUIT SCHEM LOCATION NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD NUMBER PAGE SCHEM BRD R9023 U1034 R9024 U1040A R9025 U1040B R9026 U1041A R9027 U1041B R9030 U1042A R9031 U1042B R9032 U1042C U1043A TP1040 U1043B TP1041 U1043C TP2040 U1043D TP3040 TP3041 U2011 TP4020 U2012A U2012B TP4021 U2020 TP4040 U2021 TP6010 U2022 TP7010 TP9010 U2023A TP9011 U2023B U2024 TP9040 U2025A TP9041 U2025B U2026 U1010 U1011A U2027A U1011B U2027B U1012A U2030 U1012B U2031 U1020 U2032 U2033A U1021 U1022 U2033B U1023 U2034A U1030 U2034B U1031A U2034C U1031B U2034D U2036 U1031C U1031D U2037 U1031E U2040A U1031F U2040B U1032A U2040C U1032B U2040D U2041 T Back Side Components 9 6 1502B MTDR Service Manual Diagrams A1 MAIN CIRCUIT SCHEM LOCATION NUMBER PAGE SCHEM BRD U2042A U2042B U2043 U2044 U2045A U2045B U2045C U2046 U3010 U3020A U3020B U3020C U3020D U3021 U3022 U3023 U3040 03041 03042 04020 U4021A U4021B 04040 05010 05020 05040 06040 U7010A U7010B U7040 U8010A U8010B U8010C U8040 U8041 U9030 VR3030 VR6030 T Back Side Components 1502B MTDR Service Manual 9 7 Diagrams A2 FRONT PANEL CIRCUIT SCHEM LOCATION NUMBER PAGE SCHEM BRD C1011 C1015 C2010 C201 1 C2020 C2021 C2022 C2023 C2024 C2025 C2026 C2027 C2028 C2030
173. eplaceable Mechanical Parts List Cont Fig amp Index Number FIG 10 3 10 11 12 13 14 15 16 17 18 19 20 21 22 1502B MTDR Service Manual Tektronix Part Number 620 0477 XX 211 0661 00 131 3445 00 131 4177 00 131 1857 00 211 0507 00 210 0561 00 211 0507 00 210 0561 00 253 0188 00 162 0503 00 220 0547 01 211 0105 00 441 1685 00 211 0105 00 212 0112 00 210 0007 00 204 0832 00 200 2264 00 211 0101 00 210 0202 00 Serial Effective R010141 Serial No Discont d Qty Name amp Description N rL YP n POWER SUPPLY ASSEMBLY CKT BD ASSY SEE A3A1REPL SCR ASSEM WSHR 4 40 X 0 25 PNH POZ CONN HDR MALE RTANG 2 X 7 CONN HDR MALE STR 1 X 31 W INSUL CONN HDR MALE STR 1 X 36 XSTR SEE A3A1Q2022 REPL SCR MACH 6 32 X 0 312 PNH POZ NUT PL HEEX 6 32 X 0 188 IC SEE A3A1U2010 REPL SCR MACH 6 32 X 0 312 PNH POZ NUT PL HEEX 6 32 X 0 188 TAPE PRESS SENS URETHANE FOAM INSUL SLVG ELEC 0 042 ID ACRYLIC FBRGLASS NUT BLOCK 4 40 X 0 282 SCR MACH 4 40 X 0 188 FLH POZ CHASSIS PWR SUPPLY SIDE SCR MACH 4 40 X 0 188 FLH POZ CHASSIS MOUNTED PARTS XFMR SEE A3T201 REPL SCR MACH 8 32 X 0 188 TRH SST POZ WSHR LOCK 8 EXT 0 02 SWITCH ROTARY SEEA3S201 REPL BODY FUSEHLDR 3AG amp 5 X 20MM FUSES CAP FUSEHLDR 3AG FUSES SFTY CONTROL FILTER RF SEE A3FL1 REPL 5 4 40 X 0 25 FLH 100
174. errupt or status data and then performs the required service routine The microprocessor 01023 is a single chip processor using 780 architecture constructed in high speed CMOS logic Each data word or byte is eight bits wide and the microprocessor has a 16 bit address capability allowing it to address up to 65 536 memory locations The processor s 5 MHz clock is derived from a crystal oscillator in the timebase circuits 1502B MTDR Service Manual Circuit Descriptions Address Decoding and Memory Program Memory EPROM RAM Non Volatile RAM Space Display RAM Space Enable and Select Signal Space 1502B MTDR Service Manual When 5 VDC power is applied to C1030 and R1032 the rising voltage momentarily applies a positive signal to the input of gate U1031B The resulting negative pulse at the gate output is supplied to U1023 s reset input causing the microprocessor to start at the beginning of its programmed routine each time power is applied The 16 bit address space of Z80 processor U1023 1s divided into five primary areas They are Program Memory space RAM space Non volatile RAM space Display RAM space Enable and Select Signal space The program memory is stored in 64 kilobyte kb EPROM U2020 which is divided into two 32 kb bank switched halves Both halves occupy locations OOOOH to 7FFFH in the processor s address space The most significant address bit on the EPROM which determines which
175. ervice Manual Serial No Discontd Qty Name amp Description B020616 8020797 8020816 8020616 8020797 8020816 CIRCUIT ASSY MAIN W O EPROM Con t RES FXD METAL FILM 10 OHM 1 0 2W RES FXD FILM 24 3 OHM 1 0 125W RES FXD FILM 17 4K OHM 1 0 125W RES FXD FILM 12 5K OHM 1 0 125W RES FXD FILM 200 OHM 1 0 2W RES FXD METAL FILM 49 9 OHM 0 1 0 2W RES FXD METAL FILM 1K OHM 196 0 2W RES FXD FILM 23 7K OHM 1 0 2W RES FXD FILM 8 66K OHM 1 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W RES FXD METAL FILM 100 OHM 196 0 2W RES FXD FILM 634 OHM 1 0 125W RES FXD METAL FILM 15 0K OHM 1 0 2W RES FXD METAL FILM 15 0K OHM 1 0 2W RES FXD METAL FILM 15 0K OHM 1 0 2W RES FXD FILM 2 74M OHM 1 0 125W RES FXD FILM 40 OHM 0 25 0 125W RES FXD FILM 2 74M OHM 1 0 125W RES FXD FILM 40 OHM 0 25 0 125W RES FXD FILM 210 OHM 1 0 2W RES FXD FILM 1 33K OHM 1 0 2W RES FXD FILM 8 45K OHM 1 0 125W RES FXD FILM 8 45K OHM 0 25 0 125W RES FXD FILM 8 45K OHM 1 0 125W RES FXD FILM 8 45K OHM 0 25 0 125W RES FXD METAL FILM 20 0K OHM 1 0 2W RES FXD METAL FILM 20 0K OHM 1 0 2W RES FXD METAL FILM 20 0K OHM 1 0 2W RES FXD METAL FILM 10 0K OHM 1 0 2W RES FXD METAL FILM 150 OHM 1 0 2W RES FXD METAL FILM 4 75K OHM 1 0 2W RES FXD FILM 301 OHM 1 0 2W Mfr Code 57668 57668 07716 07716 91637 57668 57668 57668 57668 57668 57668 19701 57668 57668 57668 80009 03888 80009 03888 57668 57668 80009 91637 80009 91637 57668 57668 5
176. es and holds the samples cannot instantly change from one voltage level to another It might take the circuit several samples to settle in at the new voltage after a rapid change in the waveform How efficiently the circuit moves from one sampled voltage level to the next is called sampling efficiency If the efficiency is too low the waveforms will be smoothed or rounded If the efficiency is too high above 100 the circuit will actually move beyond the new voltage level in a phenomenon known as overshoot which becomes an unwanted source of noise in the waveform Conductors all have some DC resistance to the flow of electrical energy through them The amount of resistance per unit length is usually nearly constant for a cable The energy lost overcoming this series resistance 15 called series loss The series loss must be compensated for when measuring the return loss or impedance mismatch at the far end of long cables In a cable a short circuit is a place where the signal conductor comes into electrical contact with the return path or ground conductor The electrical circuit is actually shorter than was intended Short circuits are caused by worn leaky or missing insulation The change in accuracy of a standard or item of test equipment over an extended period of time Unless otherwise specified the period of time is assumed to be the calibration interval might also apply to range resolution or precision as a function of time The ter
177. es causes a single sample of the cable voltage to be taken during a very short interval The timebase precisely controls the time delay of the sample strobe relative to the pulse strobe When many sequential samples are recombined a replica of the cable voltage is formed This sampling technique allows extremely rapid repetitive waveforms to be viewed in detail Circuit Descriptions Cable Front Panel Front End Drivers LCD Driver Sampler Hybrid Controls LCD Bias and temp compensation lt Digital Bus gt Main Board Timebase Digital Z80 Y RAM Analog ROM Signal Processing Decoding Offset gt Gain Y A D converter Option Port Power Bus gt Power Supply Control AC to DC DC DC Converter Converter Battery Figure 5 1 System Block Diagram 5 2 1502 MTDR Service Manual Circuit Descriptions 1502B MTDR Service Manual Referring to the waveforms in Figure 5 2 cable voltage waveforms are shown at the top Each step is from the pulse generator and all steps are identical At time delays ty tn l 42 etc after the steps begin a sample of the step amplitude is taken Each of these samples is
178. esirable while calibrating the instrument While in Diagnostic No Correction the circuits will not correct for these variations Front Panel Diagnostics aids in testing the front panel 1502B MTDR Service Manual Operating Instructions 1502B MTDR Service Manual LCD Diagnostics Menu has these choices i LCD Alignment Diagnostic generates a dot pattern of every other pixel on the LCD These pixels can be alternated to test the LCD ii Response Time Diagnostic generates alternate squares of dark and light reversing their order This tests the response time of the LCD and can give an indication of the effectiveness of the LCD heater in a cold environment iii LCD Drive Test Diagnostic generates a moving vertical bar pattern across the LCD iv Contrast Adjust allows you to adjust the contrast of the LCD It generates an alternating four pixel pattern The nominal contrast is set internally When in Contrast Adjust mode VERT SCALE is used as the contrast adjustment control This value ranges from 0 to 255 units and is used by the processor to evaluate and correct circuit variations caused by temperature changes in the environment When the diagnostic menu is exited the LCD contrast returns to that set by internal adjust Chart Diagnostics Menu offers various tests for the optional chart recorder i LCD Chart allows adjusting the number of dots per segment and the number of prints strikes per segment ii Head Alignme
179. ess 7973 SW CIRRUS DRIVE BLDG 22 1620 NE ARGYLE 478 NE 219TH AVENUE 3000 LEWIS AND CLARK HWY 19 030 PO BOX 4200 PO BOX 36 7330 SW LANDMARK LANE 19500 SW TETON 810 SE SHERMAN 72 VERONICA AVE UNIT 4 2015 SECOND STREET 2800 FULLING MILL PO BOX 3608 1818 CHRISTINA ST 137095 NORMANDIE AVE 446 BLAKE ST 5825 N TRIPP AVE 7100 LAMPSON AVE RICHARDS AVE 9301 ALLEN DR 6136 NE 87TH AVE PO BOX 20038 947 SE MARKET ST 515 FISHING CREEK RD 15201 BURBANK BLVD SUITE C 13026 NORMANDIE AVE 618 MAIN STREET 2400 E BURNSIDE 1800 216TH AVE NW 320 N NOPAL ST City State Zip Code BEAVERTON OR 97005 PORTLAND OR 97211 TROUTDALE OR 97060 VANCOUVER WA 98661 2999 BEAVERTON OR BEAVERTON OR 97076 4200 CEDAR RIDGE CA 95924 PORTLAND OR 97223 TUALATIN OR 97062 PORTLAND OR 97214 SUMMERSER NJ 08873 BERKELEY 94170 HARRISBURG PA 17105 ROCKFORD IL 61108 GARDENA CAS CA 90249 2609 NEW HAVEN CT 06515 1238 CHICAGO IL 60646 6013 GARDEN GROVE 92642 NORWALK CT 06852 CLEVELAND OH 44125 46 32 PORTLAND OR 97220 PORTLAND OR 97214 3556 NEW CUMBERLAND PA 17070 3007 VAN NUYS CA 91411 3532 GARDENA CA 90249 2126 WEST WARWICK RI 02893 PORTLAND OR 97214 1752 HILLSBORO OR 97124 6629 SANTA BARBARA CA 93103 3225 10 3 Replaceable Mechanical Parts Manufacturers Cross Index Cont Mfr Code 53387 53 18 7X318 70903 72228 72794 73743 74970 78189 79136 80009 83259
180. ey all have impedance An instrument that uses reflections to make measurements Our reflectometers use electrical energy that is reflected back from points along a cable A conductor s opposition to the flow of DC electrical energy through it All conductors have a certain amount of resistance Resistance 15 the low or zero frequency part of impedance For a given parameter the smallest increment or change in value that can be measured generated or displayed The amount of energy reflected or returned from a cable indicates how much the impedance in the system is mismatched The ratio of the energy sent out by the TDR divided by the energy reflected back expressed in the logarithmic dB scale is called return loss see Millirho The time it takes a pulse signal to go from 1046 to 90 of the change in voltage An acronym for Root Mean Squared RMS is a way of measuring how much deviation there is from a known or desired waveform It is also the method used to calculate how much power is contained in an AC waveform Our instruments make measurements by taking a succession of samples in time and displaying them as a waveform with voltage on the vertical scale up and down and 1502B MTDR Service Manual Glossary Series Loss Short Circuit Stability TDR Velocity of Propagation Vp Waveform Averaging 1502B MTDR Service Manual time along the horizontal scale across the display The circuitry that captur
181. f the individual at your firm who may be contacted the complete serial number of the instrument and a description of the service required If the original packaging is unfit for use or is not available repackage the instrument as follows 1 Obtain a carton of corrugated cardboard having inside dimensions that are at least six inches greater than the equipment dimensions to allow for cushioning The test strength of the shipping carton should be 275 pounds 102 5 kg Refer to the following table for test strength requirements 1502B MTDR Service Manual General Information SHIPPING CARTON TEST STRENGTH Gross Weight Ib Carton Test Strength Ib 0 10 200 11 30 275 31 120 375 121 140 500 141 160 600 shipping If it is necessary to ship the battery it should be wrapped and secured CAUTION The Option 03 battery pack should be removed from the instrument before separately before being packed with the instrument 2 Install the front cover on the 1502B and surround the instrument with polyethylene sheeting to protect the finish 3 Cushion the instrument on all sides with packing material or urethane foam between the carton and the sides of the instrument 4 Seal with shipping tape or an industrial stapler If you have any questions contact your local Tektronix Field Office or representative 1502B MTDR Service Manual XV General Information Xvi 1502B MTDR Service Manual Operati
182. f the timebase circuits is shown in Figure 5 8 next page 9 15 Circuit Descriptions Clock Generator SYSTEM CLOCKS 2 5 MHz DATA gt gt CONTROL 2 PRT Counter DATA gt gt CONTROL 5 16 2 5 MHz Course Delay Counter 0 DIGITAL TIMEBASE The digital portion of the timebase contains a clock generator that develops all frequencies used in the instrument electronics 20 MHz 5 MHz 2 5 MHz 1 25 MHz 625 KHz 7 20 MHz y gt Time Delay Circuit DRIVER TRIGGER Stobe Driver Pulse PULSE Former GENERATOR gt 20 MHz gt RAMP TRIGGER Ramp Generator Fine Delay Counter N Delay Ramp Cal 3 9 50 ns analog delay cal TIMEBASE INTERRUPT PROCESSOR CONTROL 1994109 Strobe Driver Voltage Comparator Analog limebase DAC gt SAMPLER Vref ANALOQ TIMEBASE DATA CONTROL Figure 5 8 Timebase Block Diagram A programmable digital counter clocked at 2 5 MHz is used to determine the PRT pulse repetition time of the driver sampler test pulse The 1502B is programmed with a PRT of 350 Us The output of the PRT counter is used to trigger a delay counter also clocked at 2 5 MHz
183. f zero distance delay adjustment Components C3048 R3042 R2032 C3047 R2034 and C8024 are used to reduce Jitter and cross coupling between circuits Elapsed Time Indicator SN B020511 only An elapsed time indicator M1030 is provided to measure the cumulative time the instrument has been turned on A small bead travels in the indicator as current flows through it indicating the time during which the instrument has been operating from 5 22 1502B MTDR Service Manual Circuit Descriptions Driver Sampler Introduction Second Sampler 1502B MTDR Service Manual zero to 5 000 hours After the bead has reached 5 000 hours the indicator may be replaced or simply removed and installed backwards in which case the bead will travel from 5 000 to zero hours and would have to be read backwards see Maintenance chapter The front end consists of m Hybrid Sampler Step Generator m Second Sampler m First Sampler Bridge Bias Generator m Trigger Pulse Shapers m Power Supply Conditioning The function of this board is to generate the step test signal and to sample and hold the reflections from the cable under test A block diagram of these circuits is shown in Figure 5 12 next page Most of the primary active circuitry is located within the hybrid The balance of the Driver Sampler Board is dedicated to interfacing with the rest of the instrument The step generator is triggered by a negative pulse from the Main Board O
184. ference waveform as a straight line The VIEW DIFF waveform will move up and down with the current input as you move the SPOSITION control Any of the waveforms may be turned on or off independently You might want to turn off some waveforms if the display becomes too busy or confusing NOTE Because the stored waveform is not affected by changes in the instrument controls care should be taken with current waveform settings or the results could be misleading One method to minimize the overlapping of the waveforms in VIEW DIFF is 1 Move the waveform to be stored into the top half of the display M UU eee e o o o o o e e oso oso 4 o o o e e 7 o o Figure 1 19 Waveform Moved to Top Half of Display 2 Push STORE to capture the waveform Remember once it is stored this waveform cannot be moved on the display 3 Move the current waveform the one you want to compare against the stored waveform to the center of the display 4 Push VIEW STORE and the stored waveform will appear above the current waveform 1 19 Operating Instructions 1 20 A a 3 0008 Figure 1 20 Current Waveform Centered Stored Waveform Above 5 Push VIEW DIFF and the difference waveform will appear below the current wa
185. g Max Hold ac lt gt TTO TTO 71 8169 Figure 6 37 Rising Edge with Hold 1502B MTDR Service Manual Calibration Option 03 Battery Pack Check Look in this chapter under Power Supply Checks and Adjustments for battery and charging circuit information Option 04 07 YT 1 YT 1S Chart Recorder Check If the instrument does not pass this check chart recordings might not be possible 1 Access the Chart Diagnostics Menu found under the Diagnostics Menu 2 Scroll to Head Alignment Chart and follow the directions 3 Press MENU to exit this diagnostic Figure 6 38 Head Alignment Chart Print 4 There should be approximately six Inches of narrow spaced lines and six Inches of wide spaced lines The total leneth of both should be between 10 87 and 12 76 inches Fold the paper at the last narrow spaced line and the two ends should be of equal length half narrow half wide NOTE If the chart recorder does not pass this check refer to the YT 1 Y T 1S Chart Recorder Instruction Manual 070 6270 xx for service information Option 05 Metric Default Check Option 05 requires no check other than to turn on the instrument and see if it displays in meters Instructions for changing the default can be found in the Maintenance chapter of this manual 1502B MTDR Service Manual 6 23 Calibration Ad
186. ges according to FR see table at top of next page FR Bit X in Latch Row X Output V5 non select 5 VDC select V non select Vicp select ST LP and FR are sent by the controller in such a way that a scanning select voltage is applied sequentially to the rows with the polarity of the select voltage alternating with FR every frame The alteration is required to place an AC voltage on the pixels A column driver is composed of several blocks 16 position 4 bit wide shift register 64 bit latch 64 bit level shifter and an enable flip flop A column driver has the following relevant inputs m 0300 data MSB to data LSB gt Bit pattern data for data formatted and sent by the controller XSCL column X shift clock Shifts D3 DO in parallel groups of four bits LP latch pulse Latches data in shift register into 64 bit latch FR frame signal Defines select and non select voltages Ery enable in Input to the enable flip flop enable clock Clocks Ery into the enable flip flop 9 33 Circuit Descriptions 1 Frame 8 ms gt gt 63 64 1 2
187. gure 2 13 Cursor on Lowest Major Graticule that Rising Edge crosses 5 Using the POSITION control and noting the distances displayed verify that the distance between the points where the leading edge crosses the highest and lowest major graticule lines is less than or equal to 0 096 feet 0 029 m Crosses Highest Point 0 Figure 2 14 Cursor on Highest Major Graticule that Rising Edge crosses In the above example the distances are 0 848 feet and 0 768 feet The difference between these two measurements is 0 080 feet which is well within specification Jitter is the uncertainty in the timebase Its main effect is that the waveform appears to move back and forth a very small amount If the jitter 1s too great it will affect the repeatability of very precise distance measurements 1 Setthe VERT SCALE less than or equal to 1 0 mr div 2 Watch the leading edge of the pulse move and verify that this movement 15 less than five pixels or 0 02 ft 0 006 m 2 9 Operator Performance Checks Conclusions 2 10 1 624 ft Jitter 0 F ol F Figure 2 15 Jitter Leading Edge Incident Pulse Using the Max Hold function accessed In the Setup Menu Acquisition Control can simplify your observation of jitter Hold allows you to observe the accumulated Jitter without having to stare continu
188. h and without branches Two important things to be observed when using the VIEW DIFF function m If you change either the VERT SCALE or DIST DIV you will no longer be comparing features that are the same distance apart or of the same magnitude on the display It is possible to save a feature e g a connector or tap at one distance down the cable and compare it to a similar feature at a different distance by moving the SP POSITION and POSITION controls When this is done great care should be taken to make sure the vertical and horizontal scales are identical for the two waveforms being compared If either the stored or current waveform is clipped at the top or bottom of the display the difference waveform will be affected HORZ SET REF A mode allows you to offset the distance reading For example a lead in cable to a switching network is three feet long and you desire to start the measurement after the end of the lead in cable HORZ SET REF makes it simple a 0 000 ft End of 3 ft cable Figure 1 22 Waveform of Three Foot Lead in Cable 1 Turnthe NOISE FILTER control to HORZ SET REF The noise readout on the LCD will show set A 2 Turn the P POSITION control to set the cursor where you want to start the distance reading This will be the new zero reference point For a three foot lead in cable the cursor should be set at 3 00 ft 1 21 Operating Instructions 1 22 a 1 1 00 8
189. h in the is facing toward the front of the instrument and all pins are inserted correctly in the socket Typically the lithium battery for the non volatile memory will last over seven years If it requires replacement use the following procedure CAUTION To avoid personal injury observe proper procedures for handling and disposal of lithium batteries Improper handling might cause fire explosion or severe burns Do not recharge crush disassemble heat the battery above 212 F 100 C incinerate or expose the contents of the battery to water Dispose of the battery in accordance with local state and federal regulations Typically small quantities less than 20 batteries can be safely disposed of with ordinary garbage or in a sanitary landfill but check local regulations before doing this 1 Remove the Main Board as described in a previous procedure Unsolder here Lithium CME Cell Unsolder Figure 7 8 Lithium Battery on Main Board 1502B MTDR Service Manual Maintenance Removing the Driver Sampler Board Removing the Front Panel Assembly Removing the Display Module Front Panel Board 1502B MTDR Service Manual Unsolder the four leads of the lithium battery being careful not to overheat the cell Remove the cell from the Main Board Install a new battery and solder the leads to the Main Board Be sur
190. he POSITION control to scroll to Light is ON Exit Setup Menu Acquisition Control Menu Vertical Scale is Decibels Distance Div is ft div Lightis ON Move Position to select then push MENU button Figure 6 3 Setup Menu 5 Press MENU The EL backlight should go off and the menu line will change to Light 1s OFF 6 Scroll to Light is OFF and press MENU to turn the light back on 7 Press MENU again to exit the Setup Menu 8 Press MENU again to exit the Main Menu You should be able to read the LCD in all conditions of illumination from full sunlight to a darkened room The EL backlight might very gradually begin to decrease in brightness after approximately 3 000 hours of use NOTE If the EL Backlight is dim or does not work properly refer to the Troubleshooting section or the EL Backlight Replacement section the Maintenance chapter of this manual 1502B MTDR Service Manual 6 3 Calibration Front Panel Check Ifthe instrument fails any of these checks measurements corresponding to the failed control might be inaccurate or unobtainable Presets and Menu Access 1 Setthe front panel controls CABLE No connection NOISE FILTER Full CW VERT SCALE Default see note below DIST DIV Full CW Vp 30 POWER Off NOTE A default setting is where the instrument will be set when power is switched on For example VERT SCALE will always be 0 00 dB when the instrument is powered on 2 Turn POWER
191. he current from the last two LSBs which comes from the latches through R3031 R3033 R3039 and R4020 are summed by U4021A and forced through R4021 This develops a correction voltage at TP4020 of 5 VDC and a sensitivity of 2 5 mV per bit the currents from the LSBs have been complimented by the processor to correct their phase The DAC circuit 15 designed to nominally run at half of full dynamic range 2048 4096 of 2 mA that generate 1 mA of current at summing node That current is balanced out by 1 mA of current from 4020 giving a nominal output of zero volts at TP4020 and TP4021 05020 R5020 R5021 and C5021 scale the correction signal up to 5 VDC at 4020 0 4 VDC at of 04020 Resistors R5023 R5022 furnish current to offset to a 4 VDC 0 4 VDC equivalent to 5 ns correction signal to the 50 ns analog delay To calibrate the zero distance delay IR2 is set low and through R3037 and CR3030 turns on Q3030 whose collector through R3036 and R3035 raises the cathode of CR4030 to 6 VDC This allows R4023 to turn on Q4030 Capacitor C4022 through R4030 and 04030 is charged to the new corrected level at TP4020 that was asked for by the processor The correction voltage on C4022 from buffer amplifier U4021B is scaled by voltage divider R8023 R8022 and R8021 from a range of 5 VDC toarange of zero to 3 5 VDC This voltage is applied to the base of comparator Q8020B which provides 10 ns o
192. he default 1502B MTDR Service Manual 4 1 Options and Accessories Option 07 YT 1S Chart Recorder Power Cord Options Accessories 4 2 Standard Accessories Option 07 instruments come equipped with a splashproof chart printer Refer to the YT 1 YT IS Chart Recorder Instruction Manual that comes with this option for instructions on operation paper replacement and maintenance The following power cord options are available for the 1502B TDR Note that these options require inserting a 0 15 A fuse in the rear panel fuse holder NOTE The only power cord rated for outdoor use is the standard cord included with the instrument unless otherwise specified All other optional power cords are rated for indoor use only Option 1 220 VAC 16 A Universal Europe 161 0066 09 Option A2 240 VAC 13 A United Kingdom 161 0066 10 Option 240 VAC 10 A Australia 161 0066 11 Option 4 240 15A North America 161 0066 12 Option 5 240 VAC 6 A Switzerland 161 0154 00 Replacement Fuse AC line fuse 115 159 0029 01 m Replacement Fuse AC line fuse 230 159 0054 00 B Power Cord outdoor rated 161 0228 00 m Option Port Cover Assembly 200 3737 00 m Precision 500 Test Cable S N gt 021135 012 1350 00 m 50O0BNC Terminator
193. he height of the reflected pulse to be two divisions high and read the dB return loss directly off the LCD The incident pulse is set to be two divisions high at zero dB automatically when the instrument is turned on l 1 0 000 ft Figure 1 14 Return Loss A large return loss means that most of the pulse energy was lost instead of being returned as a reflection The lost energy might have been sent down the cable or absorbed by a terminator or load on the cable A terminator matched to the cable would absorb most of the pulse so its return loss would be large An open or short would reflect all the energy so its return loss would be zero The 1502B can compute and display what impedance mismatch would cause a reflection as high or low as the point at the cursor This measurement is useful for evaluating the first impedance mismatch first reflection or small impedance changes along the cable e g connectors splices This function can be selected in the Setup Menu Once it is enabled the impedance value will be displayed under the distance in the distance window 1502B MTDR Service Manual Operating Instructions Using VIEW INPUT 1502B MTDR Service Manual ac 2 800 ft Readout Figure 1 15 Ohms at Cursor The accuracy of the difference measurement in impedance between two points near each other is much better than the absolute accuracy of any single point measurement For exa
194. hen no connector was attached to the front panel R1042 U1050 C1040 KH cR1040 R1040 RIA Figure 6 64 R1042 Driver Sampler Board 10 Remove the 3 foot precision cable 11 Verify that the waveform moves less than 0 5 division 6 39 Calibration NOTE Some changes in shape of the baseline before the leading edge is normal If this measurement is difficult to make access the Service Diagnostic Menu and change the timebase mode from Timebase 1s Normal Auto Correction to Timebase is Diagnostic No Correction This will give more stability to the pulse when the cable is connected 12 Turn the instrument off 13 Replace the Driver Sampler EMI shield Be sure the ribbon cable is placed in the center slot of the shield so it won t be crushed by the shield After Adjustments are Completed 6 40 l If the instrument is Option 05 metric refer to the Maintenance chapter to return the metric default jumper to its proper position 2 Reinstall the 1502B in its case referto the Maintenance chapter of this manual Care should be taken to follow the directions to maintain watertight integrity of the case 3 Turn back to the Calibration section of this chapter and perform all those Performance Checks that did not require case off adjustme
195. hout handle 11 8 inches 300 mm with cover on 16 5 inches 436 mm with handle extended to front 18 7 inches 490 mm 3 4 1502B MTDR Service Manual Options and Accessories The following options are available for the 15028 MTDR Option 03 Battery Pack Option 03 instruments come equipped with a rechargeable nickel cadmium battery pack Battery Pack Removal and Replacement CAUTION Read the instructions in the front of this manual concerning safety precautions necessary when charging removing or servicing the battery pack 1 Loosenthetwo knurled screws on the battery pack and pull back to remove from the rear panel of the instrument 2 Checkthatthe battery pack banana sockets are aligned correctly with the battery pack port banana plugs Push the battery pack directly into the compartment and tighten the two screws finger tight 3 Ifremoving the battery for any length of time seal the battery pack port with the battery port cover This will help seal the instrument from dirt and moisture Option 04 YT 1 Chart Recorder Option 04 instruments come equipped with a chart printer Refer to 15 Chart Recorder Instruction Manual that comes with this option for instructions on operation paper replacement and maintenance Option 05 Metric Default Option 05 instruments will power up in the metric measurements mode Standard measurements may be selected from the menu but metric will be t
196. is is the large diode next to J2010 The positive probe should be on the non banded end 7 Connect the negative probe to ground 8 Turn the 1502B POWER on The instrument should initialize and go into normal operation The display will be normal except ac in the upper left corner will have changed to bat F Figure 6 51 Display Showing Power is Battery 9 Reduce the output voltage of the DC power supply until bat low appears in the upper left corner of the display batlow 000 F Figure 6 52 Display Showing Battery Voltage is Low 10 Verify that the DC supply voltage is between 10 6 and 11 0 VDC 11 Remove the voltmeter probes from the 1502B 12 Remove the external 12 VDC power supply cable from the battery pack port 13 Connect the AC supply cord to the rear panel 1502B MTDR Service Manual Calibration Charging Current Check with optional battery pack The following test points are located on the Power Supply Board 1 Turn the POWER 2 Plug the optional battery pack into the battery pack port 3 Connecta voltmeter across the 4C resistor R2012 located on the Power Supply Board L1010 C2010 emi C2012 U2010 orae f cum CR201 CR2012 H2 gt f ce N R2012 R2011 CR2013 gt CR2014 52
197. ising Edge of Incident Pulse in Left most Major Division 7 Using the lt gt POSITION control move the cursor back to 0 000 ft 0 00 m All the aberrations except the one under the cursor see Figure 2 11 next page must be within one division of the center graticule line from out to 10 feet past the rising edge of the pulse To verify distances past the right edge of the display scroll along the waveform by turning the POSITION control clockwise 1502B MTDR Service Manual 2 7 Operator Performance Checks 2 8 7 Risetime Check ac 2 Figure 2 11 Waveform Centered Cursor at 0 000 ft If the risetime is out of specification it might be difficult to make accurate short distance measurements near the front panel 1 Set the 1502B front panel controls NOISE FILTER 1 avg VERT SCALE 500 mp div DIST DIV 0 2 ft div 0 05 m Vp 99 Using the 4 POSITION control move the incident pulse to the center of the display as shown below 1 432 ft Figure 2 12 Pulse Centered on Display 3 Turnthe VERT SCALE control clockwise until the leading edge of the incident pulse is five major divisions high about 205 mp 4 Position the waveform so that it is centered about the middle graticule line 1502B MTDR Service Manual Operator Performance Checks 8 Jitter Check 1502B MTDR Service Manual Crosses Lowest Point Fi
198. isplay Showing Low Battery Indication 1502B Front Panel Controls Display and Indicators Vp Set at 30 Cursor Beyond Reflected Pulse Set Too Low Vp Set at 99 Cursor Less Than Reflected Pulse Set TOO HICH S ders Vp Set at 66 Cursor at Reflected Pulse Set Correctly 20 ft Cable at 5 ft div Short in the Cable Open in the Cable 455 ft Cable el Reflection Adjusted to One Division in Height Return Loss Ohms at Cursor Display with VIEW INPUT Turned Off Display of a Stored Waveform Display of a Stored Waveform Waveform Moved to Top Half of Display Current Waveform Centered Stored Waveform Above Current Waveform Center Stored Waveform Above Difference Below Waveform of Three Foot Lead in Cable Cursor Moved to End of Three Foot Lead in Cable Cursor Moved to End of Three Foot Lead in Cable Cursor Moved to 0 00 ft Incident Pulse at Three Divisions Waveform of Short 750 Cable Waveform Centered and Adjusted Vertically Cursor Moved to Desired Position Waveform Viewed in Normal Operation Waveform Showing Intermittent Changes Waveform Display with No Outgoing Pulses A Captured Single Sweep 1 1 1 3 1 4 1 5 1 11 1 12 1 12 1 13 1 13 1 14 1 14 1 15 1 16 1 17 1 18 1 18 1 18
199. ite and control other circuits of the instrument The eighth 5 9 Circuit Descriptions Option Port Interface 9 10 Additional Decoding Interrupt Logic Introduction th decode signal of U1022 is used to enable four other 1 of 8 decoders U2021 U2022 02024 and 02026 These four decoders are further selected by the four combinations of 12 and and operate on Ao and Ag to generate the enable select and trigger signals CSOO through CS31 These occupy the remaining address space locations EOOOH to FFFFH An automatic wait state 1s inserted for all circuits selected by U2022 The wait state is used by the processor to compensate for the slow access times of U2041 02046 and U4020 on the Main Board U2023 on the Front Panel Board and U2040 on the display module The wait request is generated by U1041 The select signals from U2024 are also modified through U1043B by a 200 ns pulse This pulse is created from gates U1042B U1031C U2040C and J K flip flop U2033A This circuit creates a write pulse that ends prior to the completion of the processor bus cycle thus meeting data hold time requirements for some selected ICs The most significant address bit on the EPROM is set or reset by bank switching flip flop U2023A Another control signal heat disable is generated by a similar flip flop U2023B This is also toggled by two select lines The interrupt logic consists of an eight bit tri state buffer U10
200. ite Data to Read Data from Display Memory Display Memory to CPU to Controller Display Memory trom CPU Figure 5 21 CPU and Display Memory Interface 1502B MTDR Service Manual 5 39 Circuit Descriptions 5 40 Electroluminescent Backlight A This second address bus is tied to the CPU address bus through the 40 pin connector and is used to address the display memory during the time the CPU is updating the display memory The control signal DIEN controls the multiplexing of the internal address and A11 AO to MA12 MAO A15 A12 are tied low There are several other relevant control signals to the controller CS chip select WR write and RD read CS and WR are used in conjunction with AO to write to the internal registers CS and RD in conjunction with AO to read them XT 15 the system clock from which all timing in the controller is derived It 15 supplied via the 40 pin connector at 0 625 MHz DRAM display memory select is used with WR by the CPU to select and write to the display memory DRAM and RD are used to read The combinational logic associated with the selection of the display memory is such that the memory 15 set to the selected read mode at all times except when the CPU accesses it In that case it could be either selected read or selected write at the discretion of the CPU This combinational logic also controls the flow of data through the transceiver In operation the co
201. ition rate Set the 1502B front panel controls CABLE Attach 3 ft cable NOISE FILTER 1 avg 3rd position CW VERT SCALE default DIST DIV ft div 4th position CW Vp 66 Vertical Position default Horizontal Position default 2V Figure 7 14 Main Board 3041 Main Board TP4040 waveforms continued next page 1502B MTDR Service Manual 7 15 Maintenance Main Board TP7010 Figure 7 15 Main Board TP6010 x x G T Main Board TP9041 Figure 7 Figure 7 17 Front Panel CABLE Connector 1502B MTDR Service Manual 7 16 Set Front Panel controls t gt o CABLE Attach 3 ft cable lt NOISE FILTER 1 avg 3rd position CVV DIST DIV 1 4th position CVV Z Vp 66 START a Troubleshooting Chart Case Off c Y Check Power Supply TY Display dea Bad WV 4 15V 462 Good play y Yes Iretrurren responds Yes Is waveform and Shows text controls rreasurerrents nomal per Adjustrrent or graticule Procedure No No Yes Y Unplug ribbon cable from power supply Good Cycle power off on Recheck power supply per step Bad Y Y Y Y Check chart recorder Unplug each board Run front p
202. its and should be packed in shock absorbant material Send batteries post paid to Tektronix Inc Attn Bend Service 100 S E Wilson Ave Bend OR 97702 For additional information phone 1 800 835 9433 Xi Service Safety Summary Xii 1502B MTDR Service Manual _ i General Information Product Description Battery Pack Options Standards Documents and References Used Changes and History Information 1502B MTDR Service Manual The Tektronix 1502B Metallic cable Time Domain Reflectometer MTDR 15 cable test Instrument that uses radar principles to determine the electrical characteristics of metallic cables The 1502B generates a half sine wave signal applies it to the cable under test and detects and processes the reflected voltage waveform These reflections are displayed in the 1502B liquid crystal display LCD where distance measurements may be made using a cursor technique Impedance information may be obtained through interpreting waveform amplitude The waveform may be temporarily stored within the 1502B and recalled or may be printed using the optional dot matrix strip chart recorder which installs into the front panel Option Port The 1502B may be operated from an AC power source or a battery pack consisting of nine NiCad C cells which supply a minimum of five hours operating time see the Specifications chapter for specifics Options available for the 1502B are explaine
203. ive pulse The resulting positive pulse is 400 ns wide one cycle of the 2 5 MHz clock This pulse is shifted through flip flop U2036C to synchronize it with the 20 MHz clock and applied to the count enable input of U2037 a four bit programmable counter Counter U2037 will have been preset to a count of 8 through 15 by the processor through latch U2043 with CS11 While the count enable pulse is present it will count exactly eight times at the 20 MHz rate thus passing through count 15 after 0 through 7 clock pulses The terminal count TC output of U2037 is a decode of count 15 Thus this signal creates the fine delay pulse after the programmed delay This positive going pulse is gated with the 20 MHz clock by NAND gate U2045C to provide a 25 ns negative going pulse for the ramp trigger Ramp timing is derived from the trigger falling edge The end of the coarse delay detected by gate U2034C is used to clock U2027A which generates an interrupt request to inform the processor that a sample is being taken An acknowledge pulse 516 from the address decoder resets this flip flop The logic level driver trigger from the digital timebase 15 first amplified by transistor stage 09021 The trigger is capacitively coupled through C8022 and R9027 to shift it to analog levels The collector of 09021 is clamped to 0 5 VDC between pulses by CR8020 and rises to 6 VDC peak during the 25 ns pulse This signal is applied 1502B MTDR Service Manual
204. justment Procedures Equipment Required Metric Instruments Before Starting 6 24 Performance Required Example or Tek P N Digital Multimeter Range 0 to 200 VDC 501 or equivalent Ohmmeter Resolution to 0 010 DM501A or equivalent Variable AC Source with power meter GenRad W10MT3W or equiv Variable DC Power Supply 0to 14 VDC 3A 3 foot Coaxial Cable 500 012 1350 00 must be plugged into power mainframe Metric default timing is made by moving a jumper on the back of the Front Panel Board see Maintenance chapter of this manual To make the calibration easier this jumper will be moved to the standard timing position during calibration then moved back to the metric position when calibration is completed On early instruments there is an adjustment on the Main Board used for timebase compensation identified as R2034 Because of a slight crosstalk effect between circuits measurements of a certain length cable would show a small glitch This adjustment eliminated the problem and subsequent improvements in circuit board design eliminated the need for the adjustment If your instrument has this adjustment it has been set at the factory and requires no further attention Power Supply Module Main Board J Figure 6 39 Circuit Board Locations the Instrument 1502B MTDR Service Manual Calibration Remove the Case and EMI Shields Vis
205. ktronix field office or representative will contact you concerning any change in part number Change information if any is located at the rear of this manual Using the Replaceable Mechanical Parts List The tabular information in the Replaceable Mechanical Parts List is arranged for quick retrieval Understanding the structure and features of the list will help you find all of the information you need for ordering replacement parts The following table describes the content of each column in the parts list 10 1 1502B MTDR Service Manual Replaceable Mechanical Parts Parts List Column Descriptions Column Description 1 Figure amp Index Number Items this section are referenced figure and index numbers to the exploded view illustrations that follow 2 Tektronix Part Number Use this part number when ordering replacement parts from Tektronix 3and4 Serial Number Column three indicates the serial number at which the part was first effective Column four indicates the serial number at which the part was discontinued No entries indicates the part is good for all serial numbers 5 This indicates the quantity of parts used 6 Name amp Description An item name is separated from the description by a colon Because of space limitations an item name may sometimes appear as incomplete Use the U S Federal Catalog handbook H6 1 for further item name identification Mfr Code This indicates the code of the actual
206. lable at the interface This is the trigger pulse generated in the analog timebase J2010 Option Port Label on Main Board D Connector Do 3 2 D 1 1 D gt 24 25 D3 22 24 D4 20 23 Ds 18 22 Dg 16 21 D7 14 20 12 19 10 18 9 17 6 16 RD 7 4 WR 5 3 522 9 5 15028 MTDR Service Manual Circuit Descriptions J2010 Option Port Label on Main Board D Connector IA 11 6 IRA 13 7 R T TRIG 2 14 SW 16 29 13 23 12 6RTN 21 11 19 10 SW 5 17 9 SRTN 4 15 15 8 Video Processor Introduction The video processor system consists of the following m Vertical Position DAC m Summing Amplifier m Video Amplifier m Video DAC The video processor receives sampled video from the driver sampler and outputs a digitized video signal to the processor system data bus A block diagram of the video processor is shown in Figure 5 6 INTERRUPT REQUEST DATA lt VIDEO BUS ADC Sampled Video from A Driver Sampler CONTROL DATA VERTICAL POSITION gt SUMMER VIDEO E CONTROL 9 DAC AMPLIFIER AMPLIFIER DATA CONTROL Figure 5 6 Video Processor Block Diagram Vertical position information is loaded by the processor system into a DAC to generate a DC signal Sampled video is combined with this vertical position DC voltage in a summing amplifier in order to allow vertical
207. laced on the pixel matrix The voltages are placed on the matrix by the flex cable for the rows and by the elastomers for the columns LP GND N C 64 BIT SHIFT REGISTER LATCH 64 BIT LATCH FR 64 BIT LEVEL SHIFTER ROW 64 ROW 128 ROW 1 ROW 65 Figure 5 16 Row Driver Block Diagram 1502B MTDR Service Manual ST Vccd V5 V2 5 5 31 Circuit Descriptions 5 32 Row Driver The function of the row driver 15 to sequentially address each of the rows of the display The on or off state of the pixels on the addressed row 15 then determined by the voltages on the columns The row driver addresses each line one after another completing the scanning at the refresh rate of 125 Hz The column driver is similar to the row driver except bit pattern data is level shifted rather than the start pulse The column drivers provide select and non select voltages to the column electrodes according to the bit pattern data The presence of select or non select voltages on the columns in conjunction with the currently selected row pair determine which pixels are on or off on that row pair The column drivers regulate the select and non select voltages as the row drivers select rows The result is a bit pattern displayed on the screen that represents a waveform Ein Eout Eclk Xscl 16 position D3 4 bit wide E shift register DO 64 Bit Latch
208. le Elastomeric splices are used between the circuit boards and they reguire special alignment fixtures Parts replacement requires special surface mount technology Changing the Default to instrument will power up displaying DIST DIV measurements as meters Metric m div or feet ft div Although either measurement mode may be chosen from the Setup Menu the default can easily be changed to cause the preferred mode to come up automatically at power up Ribbon Cable Connectors 3 gt Front Panel Board Figure 7 11 Location of Default Jumper on Front Panel Board 1 Remove the instrument from the case 2 Remove the bottom EMI shield 3 From the bottom side of the instrument peer into the space between the Main Board and the Front Panel Board The default jumper is located behind the screw that holds the Front Panel Assembly to the front panel mounting stud 1502B MTDR Service Manual 7 13 Maintenance Removing the Option Port Assembly Troubleshooting Troubleshooting Flow Chart 7 14 Top of Instrument Front Panel Board Standard Bottom of Instrument Figure 7 12 Default Jumper Positions 4 Using a needle nose plier slip the jumper off the pins and move it to the desired default position top for meters bottom for feet Remove the Power Supply Module as shown in a previous procedure Remove the Front Panel
209. le is two divisions high ac 19 200 ft Set vertical scale and press STORE v F Figure 1 28 Waveform Centered and Adjusted Vertically 5 Press STORE 6 Return NOISE FILTER to the desired setting 7 Adjust the 3 POSITION control to the desired position on the waveform to measure loss 1502B MTDR Service Manual Operating Instructions ac 1 840 ft Figure 1 29 Cursor Moved to Desired Position The instrument is now set to measure reflections in millirho relative to the sample cable impedance To measure reflections on 500 cable the VERT SET REF must be reset 8 Toexit VERT SET REF use the following procedure a Turn NOISE FILTER to VERT SET REF b Adjust VERT SCALE to obtain an incident pulse height of two divisions c Push STORE d Turn NOISE FILTER to desire filter setting The instrument can be turned off and back on to default to the two division pulse height Additional Features Menu Selected Max Hold 1502B MTDR Service Manual The 1502B will capture and store waveforms on an ongoing basis This is useful when the cable or wire is subjected to intermittent or periodic conditions The 1502B will monitor the line and display any fluctuations on the LCD 1 Attach the cable to the 1502B front panel CABLE connector Push MENU to access the main menu Scroll to Setup Menu and push MENU again Scroll to Acquisition Control Menu and push
210. ls e suse oma ewe ewe 7 20 viii 1502B MTDR Service Manual 55 Z 5 h l h D 3 l l l l l l ll l l Qeneral Safety Summary Safety Terms and Symbols A A Power Source 1502B MTDR Service Manual The safety information in this summary is for operating personnel Specific warnings and cautions will be found throughout the manual where they apply but might not appear in this summary For specific service safety information see page xiii Terms in this manual WARNING Warning statements identify conditions or practices that could result in injury or loss of life CAUTION Caution statements identify conditions or practices that could result in damage to this product or other property Terms on the Product DANGER indicates an injury hazard immediately accessible as you read the marking WARNING indicates an injury hazard not immediately accessible as you read the marking CAUTION indicates a hazard to property including the product Symbols in the Manual WARNING or CAUTION Information Symbols on the Product 7 m DANGER Protective Ground ATTENTION Double High Voltage Earth Terminal Refer to Insulated Manual This product is intended to operate from a power source that will not apply more than 250 volts RMS between the supply conductors or between the supply conductor and General Safety Summary Grounding the Product Danger Arising from Loss
211. lse to U2033B U2033B is clocked by the 20 MHz clock and divides the 5 MHz signals to 2 5 MHz synchronously with the 20 MHz The 2 5 MHz clock is further divided to 1 25 MHz by U2025A and 625 kHz by U2025B The PRT coarse delay and real time counters are contained in a triple 16 bit programmable counter device U2030 The PRT and coarse delay counters are clocked at the 2 5 MHz rate The output of the PRT counter pin 10 of U2030 is applied to the trigger input of the coarse delay counter as a start count signal The negative going pulse from the coarse delay counter pin 13 02030 15 input to a two stage shift register U2032C and U2032D This shift register is also clocked at 2 5 MHz and serves to delay the signal and reduce its skew relative to the 20 MHz clock The Q inverted output of U2032C is a positive going pulse that is supplied to a three stage shift register U2036B U2036D U2036A which is clocked at 20 MHz from inverter U2034A The leading edge of the pulse is decoded by NAND gate U2045B which also ANDs the signal with the 20 MHz clock from inverter U2045A The resulting driver trigger pulse is a negative going pulse of nominally 25 ns width The falling edge of this pulse is determined by the edge of the 20 MHz input to gate U2045B and is used as the driver trigger The coarse delay pulse from shift register U2032D and U2032C us decoded by NOR gate U2034C to detect the pulse rising edge end of the negat
212. ltage Selector 2 j or Battery J Port Cover Line Fuse Power Cord Receptacle Figure 1 1 Rear Panel Voltage Selector Fuse AC Receptacle 1 1 Operating Instructions A Care of the Optional Battery Pack Battery Charging The 1502B is intended to be operated from a power source that will not apply more than 250 V RMS between the supply conductors or between either supply conductor and ground A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation The AC power connector is a three way polarized plug with the ground earth lead connected to the instrument frame to provide electrical shock protection If the unit is connected to any other power source the unit frame must be connected to an earth ground See Safety and Installation section CAUTION If you change the voltage selector you must change the line fuse to the appropriate value as listed near the fuse holder and in the table below FUSE RATING VOLTAGE RATING 250 V NOMINAL RANGE 115 VAC 90 132 VAC 0 15 230 VAC 180 250 VAC CAUTION Read these instructions concerning the care of the optional battery pack They contain instructions that reflect on your safety and the performance of the instrument The 1502B can be powered by an optional rechargeable Nickel cadmium battery pack that is accessible from the back of the ins
213. m stability might also be used to denote changes resulting from environmental influences such as temperature humidity vibration and shock An acronym for Time Domain Reflectometer These instruments are also called cable radar They send out pulses of energy and time the interval to reflections If the velocity of the energy through the cable is known distances to faults in the cable can be displayed or computed Conversely the speed that the energy travels through a cable of known length can also be computed The way in which the energy is reflected and the amount of the energy reflected indicate the condition of the cable Electrical energy travels at the same speed as light in a vacuum It travels slower than that everywhere else The speed that it travels in a cable is often expressed as the relative velocity of propagation This value is just a ration of the speed in the cable to the speed of light so it is always a number between 0 and 1 A velocity of propagation value of 0 50 indicates that the electrical energy moves through the cable at half the speed of light see Noise Glossary 5 Glossary Glossary 6 1502B MTDR Service Manual Index A AC see Power Ix Accessories 4 2 Optional 4 3 Standard 4 2 accessories standard 4 2 Altitude 3 3 Battery see Power Battery Pack Spec 3 2 BNC Connector 4 2 C Cable Open 1 13 Short 1 13 Test Procedure 1 12 Distance to Fault 1 12 H
214. manufacturer of the part 9 Mfr Part Number This indicates the actual manufacturer s or vendor s part number Abbreviations Abbreviations conform to American National Standard ANSI Y 1 1 1972 Chassis Parts Chassis mounted parts and cable assemblies are located at the end of the Replaceable Electrical Parts List Mfr Code to Manufacturer The table titled Manufacturers Cross Index shows codes names and addresses of Cross Index manufacturers or vendors of components listed in the parts list 10 2 1502B MTDR Service Manual Replaceable Mechanical Parts Manufacturers Cross Index Mfr Code 0DWW6 00779 01536 03038 06540 06915 08261 09922 12327 2K262 2X013 22526 22599 28334 29870 5 194 5Y 400 53217 Manufacturer MICRO PWER ELECTRONICS BADGLEY MFG CO GASKETTECHNOLOGY TRIQUEST CORP OBATA WORKS TJ BO LIAISON COMTEK MANUF OF OREGON PRECISION PRINTERS TVT DIECASTING AND MFG INC DELTA ENGINEERING STAUFFER SUPPLY FELLER SCHURTER AG H C O PANEL COMPONENTS CORP AMP INC TEXTRON INC CAMCAR DIV LONG LOK FASTENER CORP MITE CORP AMATOM ELECTRONIC HARDWARE DIV RICHCO PLASTIC CO SPECTRA STRIP AN ELTRA CO BURNDY CORP FREEWAY CORP BOYD CORP MCGUIRE BEARING CO DU POIT EI DE NEMOURS AND CO INC DU PONT ELECTRONICS DEPT AMERACE CORP ESNA DIV 3 D POLYMERS VICTOR CORP AIR OIL PRODUCTS CORP TRIAX METAL PRODUCTS INC TECHNICAL WIRE PRODUCTS INC 1502B MTDR Service Manual Addr
215. metimes subtract energy from the real signal By adding several noisy waveforms together the noise can be averaged out of the signal because the average amount of noise adding to the signal will be nearly the same as the average amount of noise subtracting from the signal More waveforms in an average are more likely to approach the real signal although it takes longer to acquire and add together more waveforms Glossary 3 Glossary Open Circuit Precision Reactance Reflectometer Resistance Resolution Return Loss Rho p Risetime RMS Sampling Efficiency Glossary 4 In a cable a broken conductor will not allow electrical energy to flow through it These circuits are also called broken circuits The circuit is open to the air which looks like a very high impedance The statistical spread or variation in a value repeatedly measured generated or displayed under constant conditions Also called repeatability A conductor s opposition to the flow of AC electrical energy through it All conductors have some reactance Reactance is made up of capacitance and inductance Capacitance is the ability of conductors separated by thin layers if insulation dielectric to store energy between them Inductance is the ability of a conductor to produce induced voltage when the electrical current through it varies All conductors have some capacitance and inductance so all conductors have some reactance which means th
216. move the Main Board taking care to avoid binding on the power switch mechanical linkage NOTE One of the corner screws see Figure 7 5 next page holds a ground strap connector 1502B MTDR Service Manual Maintenance NM e s Figure 7 5 Main Board Elapsed Time Indicator If the elapsed time indicator on the Main Board has reached 5 000 hours it may be SN B020511 only left in place replaced or reversed If the device is reversed simply read the hours backwards from 5 000 to zero hours Y M1030 Y Figure 7 6 Elapsed Time Indicator Board Replacement 1 Toreplace unsolder both ends and remove 2 Inserta new timer and re solder Reversal 1 Unsolder both ends of the timer and remove 1t from the board 2 Reverse the direction it was mounted previously re solder 1502B MTDR Service Manual 7 9 Maintenance EPROM Replacement Lithium Battery Replacement A 7 10 1 Use IC puller that is designed to extract multi pin microcircuits to remove the EPROM from its socket Front of Instrument Figure 7 7 EPROM on Main Board 2 Wheninstalling a new EPROM make sure the notc
217. mple a cable might vary from 51 3Q to 58 4 2 across a connector the 7 1 2 difference is accurate to about 2 The 51 35 measurement by itself is only specified to be accurate to 10 The series resistance of the cable to the point at the cursor affects the accuracy of the impedance measurement directly In a cable with no large impedance changes the series resistance 15 added to the reading For example the near end of a long 50 2 coaxial cable might read 51 5 2 but increase to 57 5 2 several hundred feet along the cable The 602 difference 15 due to the series resistance of the cable not to a change in the actual impedance of the cable Another limitation to the ohms at cursor function 15 that energy is lost going both directions through a fault This will cause readings of points farther down the cable to be less accurate than points nearer to the instrument In general it is not wise to try to make absolute measurements past faults because the larger the fault the less accurate those measurements will be Although they do not appear as faults resistive pads often used to match cable impedances also affect measurements this way When pushed the VIEW INPUT button displays the input at the front panel CABLE connector When VIEW INPUT 15 turned off and no other buttons are pushed the display will not have a waveform on it see Figure 1 16 next page The default condition when the instrument is powered up is to have VIEW IN
218. n from the battery pack to only a few microamperes 1502B MTDR Service Manual Circuit Descriptions Post Regulator DC to DC Converter Processor System Introduction 1502B MTDR Service Manual The post regulator receives from 49 7 to 15 5 VDC and boosts it to 16 2 VDC by switching Q2022 on and off with a pulse width modulated signal When Q2022 is turned on input voltage is applied across choke L2020 causing the current in L2020 to increase When Q2022 1s turned off the stored energy in L2020 will cause the current to continue flowing through CR2021 to filter capacitor C2025 Due to its stored energy the voltage developed across L2020 adds to the input voltage allowing C2025 to be charged to a voltage greater than the input The switching of Q2022 is controlled by pulse width modulator U1023 The post regulator output voltage is fed back to U1023 through R1025 and R1024 and compared to the 2 5 VDC reference from U1022 Low output voltage causes wider pulses to be supplied to Q2022 storing more energy in L2020 during each pulse This results in a higher output voltage High output voltage however reduces pulse width and reverses the preceding process U1023 oscillates at approximately 80 kHz and supplies a synchronizing signal to the pre regulator at that frequency when the instrument is operating on AC power This raises the pre regulator frequency to the same 80 KHz This synchronization eliminates beat frequency interfe
219. nd display it on the LCD A block diagram of the display module is shown in Figure 5 14 column driver 4 x bpard to board elastomer column 64 64 64 64 elastome X 9 DATA CONTROL DATA CONTROL gt lt y re 64 upper DISPLAY DATA gt MEMORY ADDR HO DRIVER 128 X 256 N L Z ZEN W gt SBE CELL N l ZX CONTROLLER 64 lower teed Feel eed column elastomer 54 64 64 64 64 40 flex cable column driver 4 ROW DRIVER CONTROLLER BOARD COLUMN DRIVER BOARD Figure 5 14 Display Module Block Diagram The LCD cell is the video screen that displays information generated by the processor The processor updates the display memory periodically with a new picture and the display memory holds this bit pattern data This data 15 received by the display controller and sent to the drivers along with some control and timing signals that provide operating information to the drivers The row and column drivers are attached electrically to the LCD cell through elastomeric connectors and 5 29 Circuit Descriptions 5 30 LCD Cell a flex cable These drivers place signal voltages on the electrode matrix in the LCD cell and thus generate the video display There are other circuits cont
220. ne of the trigger pulse shapers stretches this to 25 ps to set the length of the output step The 0 6 V adjustable power source sets the on voltage for the output step The sampler is also triggered by a negative pulse from the Main Board Inside the hybrid this trigger causes the strobe generator to apply 50 ps pulses to turn on the bridge capturing a portion of the input waveform This sample is stored outside the hybrid in the second sampler to reduce droop rate The stored signal goes two places back to the Main Board as the video output and to the bridge bias circuit which holds the sampling bridge off between samples The video signal from the hybrid is sent to the second sampler The second sampler reduces the droop rate to about 1 LSB ms This is accomplished by buffering the signal through U2050B and storing it in C2053 via the FET switch Q1060 The FET is strobed by the one shot U3030B for 5 Us after the sample is taken The voltage stored on C2053 is buffered by op amp U2050A then inverted and amplified by U1050A The strobe signal for the FET can be observed at 2060 and the inverted video output at TP1060 The signal from the second sampler buffer U2050A is also fed to the bridge bias amp U1070 via R1060 5 23 Circuit Descriptions
221. nel Board Removal 7 11 Removal from Display Module 7 12 Fuse Holder Removal 7 7 1502B MTDR Service Manual Main Board Elapsed Time Indicator 7 9 EPROM Replacement 7 10 Lithium Battery 7 10 Removing 7 8 Option Port Assembly Removal 7 14 Power Cord Conductor Color Code 7 7 Power Cord Receptacle Removal 7 6 Power Supply Board Removal 7 6 Power Supply Module Removal 7 5 Power Transformer Removal 7 6 Remove Case 7 3 Remove EMI Shields 7 3 Sealing Materials 7 20 Voltage Selector Removal 7 7 Preventive 7 1 Cleaning 7 1 Lubrication 7 2 Recalibration 7 2 Visual Inspection 7 2 Troubleshooting 7 14 Flow Chart 7 14 Waveforms 7 15 When All Else Fails 7 20 Manual Changes xiii Maximum Hold 1 25 Menu 1 7 1 25 Cables 1 7 Diagnostics 1 8 Chart Recorder 1 9 Head Alignment 1 9 LCD Chart 1 9 Front Panel 1 8 LCD 1 9 Alignment 1 9 Contrast 1 9 Drive Test 1 9 Response Time 1 9 Service 1 8 Noise 1 8 Offset 1 8 RAM ROM 1 8 sampling Efficiency 1 8 Timebase 1 8 Display Contrast 1 10 Impedance 1 7 Main 1 7 Maximum Hold 1 25 Option Port 1 9 Debugging 1 9 Diagnostic 1 9 Timing 1 9 Pulse 1 26 setup 1 7 Acquisition Control 1 7 Backlight 1 8 Distance Division 1 8 Maximum Hold 1 7 Pulse 1 7 Index 3 Index single Sweep 1 7 Vertical Scale 1 8 singl
222. nerating circuitry 1s turned on and off the pulse is often distorted slightly and no longer is a perfect step or sine shaped waveform Alternating current is a method of delivering electrical energy by periodically changing the direction of the flow of electrons in the circuit or cable Even electrical signals designed to deliver direct current DC usually fluctuate enough to have an AC component The difference between a measured generated or displayed value and the true value Electrical conductors that are usually insulated and often shielded Most cables are made of metal and are designed to deliver electrical energy from a source such as a radio transmitter across a distance to a load such as an antenna with minimal energy loss Most cables consist of two conductors one to deliver the electrical signal and another to act as a return path which keeps both ends of the circuit at nearly the same electrical potential In early electrical systems and modern systems that over long distances use the earth and or air as the return path and the term eround or ground wire 15 often used to describe one of the wires in a cable pair The amount of signal that is absorbed in the cable as the signal propagates down it Cable attenuation 15 typically low at low frequencies and higher at high frequencies and should be corrected for in some TDR measurements Cable attenuation is usually expressed in decibels at one or several frequencies See also
223. ng Instructions Overview Handling Powering the 1502B 1502B MTDR Service Manual The 1502B front panel is protected by a watertight cover in which the standard accessories are stored Secure the front cover by snapping the side latches outward If the instrument is inadvertently left on installing the front cover will turn off the POWER switch automatically The carrying handle rotates 325 and serves as a stand when positioned beneath the instrument Inside the case at the back of the instrument is a moisture absorbing canister containing silica gel In extremely wet environments it might be be necessary to periodically remove and dry the canister This procedure 15 explained in the 75025 Service Manual The 1502B can be stored in temperatures ranging from 62 C to 85 C However if the temperature is below 40 C or above 455 the battery pack should be removed and stored separately Battery storage temperature should be 40 C to 4 55 In the field the 1502B can be powered using the optional internal battery For AC operation check the rear panel for proper voltage setting The voltage selector can be seen through the window of the protective cap If the setting differs from the voltage available it can be easily changed Simply remove the protective cap and select the proper voltage using a screwdriver Ol TRORA SELECT REPLACE volt o
224. not lift the instrument by the front panel controls The controls will be damaged if you do so 8 9 Remove the screws holding the shields to the back frame Remove the screw in the middle of the bottom EMI shield 10 Remove the EMI shields from the top and bottom of the chassis by carefully running a straight blade screwdriver between the shield and the groove in the chassis rail Check the desiccant cartridge mounted on the rear of the chassis inside the case If the crystals of silica seen through the window of the cartridge are blue the dehydrating agent is active and no further maintenance is required 7 3 Maintenance A Rejuvenating the Desiccant Cartridge SN lt B037562 only CAUTION In a humid environment it is imperative that the desiccant be checked to see if itis active High humidity within the instrument can cause component damage including the LCD Use caution when disassembling the instrument in a high humidity environment Make sure the instrument is reassembled with rejuvenated agent per the following instructions If the silica has turned pink the cartridge must be rejuvenated per the following procedure CAUTION Do not disassemble the cartridge The drying action of this material causes irritation of the mucous membranes of the nose and throat and irritation of the skin Although it is considered non toxic avoid ingestion If the material comes in contact with the eyes wash it from th
225. nside the case and use your fingers to push the four captive mounting screws out so that their heads stick up and out of the rear feet 3 Align the case with the chassis 7 22 1502 MTDR Service Manual Maintenance 1502B MTDR Service Manual Gently lower the case over the chassis until the front of the case makes contact with the groove that surrounds the front panel casting Using a flat blade screwdriver secure the four mounting screws seven inch pounds of torque Each screw should be started by turning it counterclock wise once then clockwise Alternately tighten each screw gradually a few turns at a time Check the gap between the case and the front panel casting to make sure that the case and front panel are mated evenly all around If not mated properly loosen the screws reposition the case then tighten the screws again 7 23 Maintenance 7 24 1502B MTDR Service Manual Replaceable Electrical Parts Parts Ordering Information List of Assemblies Mfr Code Number to Manufacturer Cross Index Abbreviations Component Number 1502B MTDR Service Manual Replacement parts are available from your Tektronix field office or representative When ordering parts include the part number plus instrument type serial number and modification number if applicable If a part is replaced with a new or improved part your Tektronix representative will contact you regarding any change in part number
226. nstrument fails this check the waveforms might not look normal If the Check efficiency is more than 100 the waveforms will appear noisy If the efficiency is below the lower limit the waveform will take longer more pixels to move from the bottom to the top of the reflected pulse This smoothing effect might completely hide some faults that would normally only be one or two pixels wide on the display 1 In the Service Diagnostic Menu select Sampling Efficiency and follow the directions on the screen 2 Whendone with the test press the MENU button repeatedly until the instrument returns to normal operation 6 Aberrations Check Ifthe aberrations are out of specification the ohms at cursor function might be less accurate than specified 1 Connect the 50Q precision terminator to the front panel CABLE connector 2 Setthe DIST DIV control to 5 ft div 1 m div 3 Increase the VERT SCALE control to 50 mp div 4 Using the POSITION control move the top of the pulse to the center graticule line 2 6 1502B MTDR Service Manual Operator Performance Checks nn aD Figure 2 9 Top of Pulse on Center Graticule 5 Set the DIST DIV control to 0 2 ft div 0 05 m div 6 Turn the POSITION control clockwise until the rising edge of the incident pulse is in the left most major division on the display ac 1160 FE Figure 2 10 R
227. nt Chart generates a pattern to allow mechanical alignment of the optional chart recorder View Stored Waveform Settings displays the instrument settings for the stored waveform Option Port Menu contains three items Two items allow configuration of the option port for communicating with devices other than the optional chart recorder and one item test the option port a Option Port Diagnostic creates a repeating pattern of signals at the option port to allow service technicians to verify that all signals are present and working correctly Set Option Port Timing allows adjustment of the data rate used to communicate with external devices The timing rate between bytes can be set from about 0 05 to 12 8 milliseconds Option Port Debugging Is Off On Off is quiet On is verbose This chooses how detailed the error message reporting will be when communi cating with an external device Itis possible to connect the instrument to a computer through a parallel interface with a unique software driver Because different computers vary widely in Operating Instructions Test Preparations The Importance of Vp Velocity of Propagation Vp of Various Dielectric 1 10 Types processing speed the instrument must be able to adapt to differing data rates while communicating with those computers With user developed software drivers the ability to obtain detailed error messages during the development can be very useful For more inf
228. nt is a resistive plating of indium tin oxide ITO on the back side of the row pane This plating has a resistance of about 64Q The power for the heater is supplied through the 40 pin connector to pads on the Row Driver Controller Board similar to those for the EL backlight A thermistor RT 1030 is attached to the of the row pane opposite the cable This thermistor is used to track the temperature of the LCD cell and turn on the heater power 16 VDC when the temperature falls below 5 C With a supply voltage of 16 VDC the heater dissipates about 4W The circuitry to control the temperature is located on the Front Panel Board The thermistor leads are attached to pads on the Row Driver Controller Board similar to the heater and routed through the 40 connector 5 41 Circuit Descriptions 5 42 1502B MTDR Service Manual Calibration Introduction This chapter 15 divided Into the Calibration Performance Check and the Adjustment Procedure The Calibration Performance Check 15 a series of checks to compare the instrument parameters to the published specifications This procedure is similar to the Operator Performance Check Chapter 2 but additionally lists actions to take if the Calibration Performance Check is not met The Adjustment Procedure is a series of steps designed to bring the instrument up to standards after repair or performance check Calibration Performance Check Equipment Required Getting Re
229. ntroller is usually accessing the display memory and refreshing the screen with the bit pattern data At the rate of about 10 Hz the CPU intervenes in the refresh operation to update the bit pattern display memory This operation occurs as a block transfer of 4k X 8 from the CPU memory to the display memory This block transfer takes place in about 17 ms During thew block transfer the controller cannot access display memory and therefore sends null data to the display Because the LCD display is non emitting a light source is needed for low light applications This source is provided by an electroluminescent EL backlight behind the transflector The EL backlight 15 a long life device requiring a 130 400 Hz supply This supply is routed from the Front Panel Board through the 40 pin connector to pads on the Row Driver Controller Board The leads on the backlight are then attached to these pads CAUTION The pads for the EL backlight are exposed when the display module is removed from the front panel They operate from a high voltage source Do not turn on the backlight when the pads are exposed 1502B MTDR Service Manual Circuit Descriptions Indium Tin Oxide Heater 1502B MTDR Service Manual Because the LCD display response time slows down rapidly at temperatures below 10 a heater is required to maintain the temperature of the LCD cell at 4 10 C when the ambient temperature falls below 4 10 The heating eleme
230. nts 1502B MTDR Service Manual Maintenance Introduction Equipment Required This chapter contains information on preventive and corrective maintenance troubleshooting panel control assembly procedures and shipping instructions Please refer to schematics for physical location of circuits and components NOTE We recommend that service be performed at an authorized Tektronix Service Center or by a technician skilled in sampling and pulse techniques This is a list of common tools needed to accomplish all the maintenance procedures that follow 5 16 hex nut driver P hillips head screwdriver 11 32 hex nut driver Straight blade screwdriver 1 16 hex wrench Torque driver 5 16 open end wrench Soldering and desoldering tools 1 16 open end wrench Cotton swabs non woven wipes 1 2 open end wrench Isopropyl alcohol LocTite etc Preventive Maintenance Cleaning A 1502B MTDR Service Manual Preventive maintenance includes cleaning visual inspection and lubrication A convenient time to perform preventive maintenance is during the periodic performance check calibration procedure If the instrument has been subjected to extreme environments or harsh handling more frequent maintenance might be necessary CAUTION Do not use chemical agents that contain benzene toluene xylene acetone etc because of possible damage to plastics in the instrument The exterior case and front panel should be washed gently wi
231. od desired Timebase control by the processor system 1s shown in Figure 5 9 Each period of the pulse rate the processor calculates a new 33 bit digital time delay value for the next sample to be taken The sixteen most significant bits of this value are loaded into the coarse delay counter causing it to count that number of 2 5 MHz clock periods before starting the fine delay counter 33 BIT LSB DIGITAL TIME 16 BITS 14 BITS DELAY VALUE COURSE FINE BUS E DELAY DELAY 2 COUNTER COUNTER 2 5 MHz 20 MHZ STROBE TO CLOCK CLOCK SAMPLER Figure 5 9 Timebase Control The next three bits from the processor time delay value are loaded into the fine delay counter This counter starts at the end of the coarse delay and counts the selected number of 20 MHz clock periods o through 7 before triggering the analog delay The analog delay circuit receives the 14 least significant bits of the time delay word A digital to analog conversion provides a proportional voltage which is compared to a linear voltage ramp to produce the programmed time delay o to 50 ns The timing diagram in Figure 5 10 next page shows the combined effects of the three time delays The output of the PRT counter waveform a begins the coarse delay b The falling edge of this signal triggers the driver strobe c which causes a pulse to be applied to the cable test output 9 17 Circuit Descriptions PRT COU
232. of Ground Use the Proper Power Cord Use the Proper Fuse Do Not Operate in Explosive Atmosphere Do Not Remove Covers or Panels ground A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation This product is grounded through the grounding conductor of the power cord To avoid electrical shock plug the power cord into a properly wired receptacle before connecting to the product input or output terminals A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation Upon loss of the protective ground connection all accessible conductive parts including knobs and controls that appear to be insulating can render an electric shock Use only the power cord and connector specified for this product Do not use this instrument without a rated AC line cord The standard power cord 161 0288 00 is rated for outdoor use All other optional power cords are rated for indoor use only Use only a power cord that is in good condition Refer cord and connector changes to qualified service personnel To avoid fire hazard use only a fuse of the correct type Refer fuse replacement to qualified service personnel To avoid explosion do not operate this product in an explosive atmosphere unless it has been specifically certified for such operation To avoid personal injury do not remove the product covers or panels Do not
233. of Propagation controls are set according to the 32 26 2 0 gg propagation velocity factor of the cable tested For example solid a7 polyethylene commonly has a Vp of 0 66 Solid polytetraflourethylene Teflon es i is approximately 0 70 Air is 0 99 The controls are decaded the left control is the first digit and the right control is the second digit For example with a Vp of 0 30 the first knob would be set to 3 and the second knob to 00 6 POWER Pull for power ON and push in for power OFF When the front cover POWER PULL ON C is installed this switch is automatically pushed OFF POSITION 7 POSITION This is continuously rotating control that positions the displayed waveform vertically up or down the LCD 8 POSITION This is a continuously rotating control that moves a vertical lt I gt POSITION cursor completely across the LCD graticule In addition the waveform is also lt moved when the cursor reaches the extreme right or left side of the display A readout seven digits maximum is displayed in the upper right corner of the LCD showing the distance from the front panel BNC to the current cursor location 9 MENU This pushbutton provides access to the menus and selects items chosen from menus 10 VIEW INPUT When pushed momentarily this button toggles the display of VIEW the waveform a
234. of the front panel CABLE connector 4 Subtract the resistance of the Ohmmeter test probes The result should be between 49 5 Q and 50 5 Q LCD Check and Adjustment 1502B MTDR Service Manual 1 Turn POWER on 2 Push MENU 3 Using the SPOSITION control scroll to Diagnostics Menu 4 Push MENU 5 Scroll to LCD Diagnostics Menu 6 Push MENU 7 Scroll to LCD Alignment Diagnostic 8 Push MENU R1018 Figure 6 56 R1018 on Front Panel Board 9 Observe the LCD as you adjust R1018 Contrast Adjust counterclockwise until the entire pattern starts to dim 45 8725 n 5 f 4 5477 545 53 5 47 544 5 54 22555692 ps e gt 5 shes Figure 6 57 LCD Pattern with Contrast Too Light 6 35 Calibration 6 36 Figure 6 58 LCD Pattern with Contrast Too Dark 10 Turn R1018 clockwise until the entire pattern 15 clear and sharp Push MENU 1 sec to alternate 2 secs to quit Figure 6 59 LCD Pattern Adjusted for Sharpness 11 Press MENU once quickly The ON pixels will be toggled off and the OFF pixels will be toggled on Watch to see if all the pixels are being activated 12 Once contrast has been set using the LCD pattern verify it with a normal waveform display a Ensure that the instrument has been at 75 F 5 25 3 C for at least one hour operating or non
235. on It will show as an upward shift or bump on the waveform If rho 15 negative it indicates an impedance lower than that of the cable prior to the reflection It will show as a downward shift or dip on the waveform If the cable has an open or short all the energy sent out by the 1502B will be reflected This is a reflection coefficient of rho 1 or 1000 mp for the open and 1000 mp for the short Long cables have enough loss to affect the size of reflections In the 1502B this loss will usually be apparent as an upward ramping of the waveform along the length of the cable In some cases the reflection coefficient measurement can be corrected for this loss This correction can be made using a procedure very similar to the Vertical Compensation for Higher Impedance Cable procedure see the VERT SET REF section Return loss is another was of measuring impedance changes in a cable Mathematically return loss is related to rho by the formula Return Loss in dB 20 log base ten of Absolute Value of Rho Veet Vinc The 1502B can be made to display in dB instead of mp div through the menu 1 Press MENU 1 15 Operating Instructions Ohms at Cursor 1 16 Select Setup Menu Press MENU again Select Vertical Scale is Millirho Press MENU again This should change 15 to Vertical Scale is Decibels m E de A di Press MENU twice to return to normal operation To measure return loss with the 1502B adjust t
236. on Wait for initialization and normal operation display 3 Press MENU 4 Use the SPOSITION control to scroll to Diagnostics Menu Return to Normal Operation Help with Instrument Controls Cable Information Menu Setup Menu Diagnostics Menu View Stored Waveform Settings Option Port Menu Move 2 to select then push MENU button Figure 6 4 Main Menu 5 Press MENU This will display the Diagnostics Menu 6 4 1502B MTDR Service Manual Calibration Pushbutton Switches Rotating Controls 1502B MTDR Service Manual Exit Diagnostics Menu Service Diagnostic Menu FrontPanel Diagnostic LCD Diagnostics Menu Chart Diagnostics Menu Move Position to select then push MENU button Figure 6 5 Diagnostics Menu 6 Use the POSITION control to scroll to Front Panel Diagnostic 7 Press MENU This will display the Front Panel Diagnostics Press VIEW INPUT The LCD switch reading should change to 1 see Figure 6 6 third line of text Front Panel Diagnostic test all switches Hold down MENU button to Exit Switch 1 0 30 lt Control 76 292 Switch Reading A Vertical Scale 230 61 Figure 6 6 Front Panel Diagnostic Display Press VIEW STORE The LCD switch reading should change to 2 3 Press VIEW DIFF The LCD switch reading should change to 3 4 Press STORE The LCD switch reading should change to 4 5 Rotate NOISE FILTER c
237. on top of Main Board Figure 6 43 Connector Plug P5040 and Pins J5040 on Bottom of Main Board Test points in this check are located on the Power Supply Board 1 Connect the positive probe to the 16 6 VDC supply TP1020 on the Power Supply Board 0 4 R1015 1 R1016 f 4 R1011 f R1010 7 R1012 01010 01011 f VR1012 CR1010 C1012 c rur R1017 4 R1022 Q1010 Figure 6 44 Power Supply Test Point TP1020 Change the AC output voltage on the Variac to 132 VAC Verify that the 16 6 VDC supply remains regulated 16 4 to 16 8 VDC Reduce the Variac output voltage to 90 Verify that the 16 6 VDC supply is still regulated 16 4 to 16 8 VDC Move the positive probe to the 16 2 VDC supply TP2030 SU dex eS D Reduce Variac output voltage until the 16 2 VDC and the instrument shut down This voltage must be lower than 90 VAC 1502B MTDR Service Manual Calibration Q2030 Q2022 Q2031 S CR2030 S CR2031 2027 F pm 7 R2030 TP2030 CR2021 Figure 6 45 Power Supply Test Point 2030 8 Raisethe Variac output voltage to 120
238. onix Part Number 670 9285 XX 281 0925 01 290 0748 00 152 0322 00 152 0322 00 152 0322 00 152 0322 00 152 0322 00 152 0141 02 152 0322 00 152 0725 00 152 0725 00 152 0322 00 152 0322 00 152 0322 00 131 3361 00 131 4183 00 131 3359 00 120 1606 00 108 0509 01 149 0057 00 151 1176 00 151 0190 00 151 0188 00 151 0190 00 151 0188 00 151 1176 00 151 1176 00 Effective B021135 R010100 Serial No Discontd Qty Name amp Description R020511 CIRCUIT BD ASSY MAIN W O EPROM Con t CAP FXD CER DI MLC 0 22UF 2096 50V Z5U CAP FXD ELCTLT 10UF 50 20 25W VDC DIODE DVC DI SCHOTTKY 51 15 1 2 DIODE DVC DI SCHOTTKY 51 15 1 2 DIODE DVC DI SCHOTTKY 51 15 1 2 DIODE DVC DI SCHOTTKY 51 15 1 2 DIODE DVC DI SCHOTTKY 51 15 1 2 DIODE SIG ULTRA FAST 40V 150MA 4NS 2PF DIODE DVC DI SCHOTTKY SI 15V 1 2PF DIODE DVC DI SI SCHOTTKY 20V 1 2PF DIODE DVC DI SI S CHOTTKY 20V 1 2PF DIODE DVC DI S CHOTTKY SI 15V 1 2PF DIODE DVC DI SCHOTTKY SI 15V 1 2PF DIODE DVC DI SCHOTTKY SI 15V 1 2PF CONN HDR PCB MALE RTANG 2 X 13 0 1 CTR CONN HDR PCB MALE STR 2 X 7 0 1 CONN HDR PCB MALE RTANG 2 X 10 0 1 CTR XFMR RF INDUCTOR 86 10 COIL RF FIXED 2 45UH 1090 AXIAL LEAD METER ET MINITURE 620 PC XSTR PWR MOS P CH 100V 1 0A 0 6 OHM XSTR SIG BIPOLAR NPN 40V 200MA 300MHZ AMP XSTR SIG BIPOLAR PNP 40V 200MA 250MHZ AMP XSTR SIG BIPOLAR NPN 40V 200MA 300MHZ AMP XSTR SIG BIP
239. ont panel controls This allows you to observe front panel changes without exiting the Single Sweep mode As in normal operation averaged waveforms will take longer to acquire Figure 1 33 Captured Single Sweep 8 To exit Single Sweep is On access the Acquisition Control Menu again turn the Single Sweep back off then repeatedly push MENU until the instrument returns to normal operation 1502B MTDR Service Manual Operator Performance Checks Equipment Required Getting Ready Power On Metric Instruments 1502B MTDR Service Manual This chapter contains performance checks for many of the functions of the 1502B They are recommended for incoming inspections to verify that the instrument is functioning properly Procedures to verify the actual performance requirements are provided in the 15026 Service Manual Performing these checks will assure you that your instrument is in good working condition These checks should be performed upon receipt of a new instrument or one that has been serviced or repaired It does not test all portions of the instrument to Calibration specifications The purpose of these checks is not to familiarize a new operator with the instrument If you are not experienced with the instrument you should read the Operating Instructions chapter of this manual before going on with these checks If the instrument fails any of these checks it should be serviced Many failure mo
240. option either will repair the defective product without charge for parts and labor or will provide a replacement in exchange for the defective product Inorderto obtain service under this warranty Customer must notify Tektronix ofthe defect before the expiration of the warranty period and make suitable arrangements for the performance of service Customer shall be responsible for packaging and shipping the defective product to the service center designated by Tektronix with shipping charges prepaid Tektronix shall pay for the return of the product to Customer if the shipment is to a location within the country in which the Tektronix service center is located Customer shall be responsible for paying all shipping charges duties taxes and any other charges for products returned to any other locations This warranty shall not apply to any defect failure or damage caused by improper use or improper or inadequate maintenance and care Tektronix shall not be obligated to furnish service under this warranty a to repair damage resulting from attempts by personnel other than Tektronix representatives to install repair or service the product b to repair damage resulting from improper use or connection to incompatible equipment or c to service a product that has been modified or integrated with other products when the effect of such modification or integration increases the time or difficulty of servicing the product THIS WARRANTY IS GIVEN BY TEKTRO
241. or on the rising edge of waveform at the first graticule up from the centerline 8 Press STORE 1502B MTDR Service Manual Calibration 1502B MTDR Service Manual a i Lo 0108 ft move cursor to reference and Press STORE I Figure 6 12 Cursor on Rising Edge of Pulse 9 Rotate NOISE FILTER back to 1 avg 10 Press STORE The front panel reference has now been set a usus uuu uuu Figure 6 13 Cursor at 0 000 ft A 11 Rotate the 4 POSITION control to the rising edge of the waveform one graticule above the centerline This measures the distance from the set point to the end of the 3 ft cable The measured distance should be between 2 87 and 3 13 feet a AIBB A TTO Figure 6 14 Cursor on Rising Edge of Pulse 12 Remove the 3 ft cable and connect the 500 terminator 6 9 Calibration Zero Offset Check 6 10 13 Set the DIST DIV control to 200 ft div 14 Rotate the POSITION control clockwise until the display distance window shows a distance greater than 2 000 000 ft The waveform should remain flat from zero to this distance ase F F Figure 6 15 Flatline Display to gt 2 000 ft NOTE If the Timebase does not appear to be working properly refer to the Circuit Descriptions chapter and the Troubleshooting section of the Main
242. orizontal Set Reference 1 21 Reflection Coefficient 1 14 Return Loss 1 15 Store Waveform 1 18 Vertical Set Reference 1 23 View Difference 1 19 View Input 1 17 View Store 1 18 Calibration Adjustment Procedure 6 24 Case Shield Removal 6 25 Equipment Required 6 24 LCD 6 35 Metric Instruments 6 24 Power Supply 6 25 Charging Current 6 33 DC Power 6 30 Main Board 12 V 6 29 Power Up 6 25 Range Check 6 28 Voltage Checks 6 26 Timebase Compensation 6 24 Visual Inspection 6 25 Zero Offset 6 38 General 6 1 Performance Check 6 1 Battery Pack 6 23 Chart Recorder 6 23 Display Module 6 2 EL Backlight 6 3 LCD 6 2 Equipment Required 6 1 Front Panel 6 4 Menu Access 6 4 Presets 6 4 Pushbutton Switches 6 5 Rotating Controls 6 5 1502B MTDR Service Manual Thermistor 6 7 Getting Ready 6 1 Horizontal Scale 6 7 Impedance 6 34 Jitter 6 21 Metric Default 6 23 Metric Instruments 6 1 Noise 6 13 Offset 6 12 Offset Gain 6 16 Pulse Balance 6 17 RAM ROM 6 16 Risetime 6 19 sampling Efficiency 6 15 Timebase 6 7 Vertical Position 6 12 Zero Offset 6 10 Characteristics Electrical 3 1 Environmental 3 3 Physical 3 4 Checks see Performance Checks Circuit Description Display Module Block Diagram 5 29 Column Driver 5 33 Block Diagram 5 32 Timing Diagram 5 35 Column
243. ormation contact your Tektronix Customer Service representatives They have information describing the option port hardware and software protocol and custom development methods available 8 Display Contrast Software Version 5 02 and above a Pressthe MENU button firmly once If the display 15 very light or very dark you might not be able to see a change in the contrast b Turnthe VERTICAL SCALE knob slowly clockwise to darken the display or counterclockwise to lighten the display If you turn the knob far enough the contrast will wrap from the darkest to lightest value c Whenthe screen is clearly readable press the MENU button again to return to normal measurement operation The new contrast value will remain in effect until the instrument is turned off Vpis the speed of asignal down the cable given as a percentage of the speed of light in free space It is sometimes expressed as a whole number e g 66 or a percentage e g 66 On the 1502B it is the percentage expressed as a decimal number e g 66 66 If you do not know the velocity of propagation you can get a general idea from the following table or use the Help with Cables section of the Cable Information menu You can also find the Vp with the procedure that follows using a cable sample NOTE If you do not know the Vp of your cable it will not prevent you from finding a fault in your cable However if the Vp is set wrong the distance readings will be affecte
244. ounterclockwise to VERT SET REF The switch reading on the display should be 5 6 Slowly rotate this control clockwise to its far stop Each position should increase the switch reading one count starting at 5 and ending with 14 6 5 Calibration 6 6 10 Rotate DIST DIV counterclockwise to its far stop The switch reading on the display should be 15 Slowly rotate this control clockwise to its far stop Each position should increase the switch reading one count starting at 15 and ending with 25 The display should currently show a Vp of 0 30 Slowly rotate the left Vp control to full clockwise Each click should correspond to the front panel control setting Rotate the right Vp control to full clockwise Again the LCD reading should match the front panel control setting The final reading with both controls fully clockwise should be 0 99 Front Panel Diagnostic test all switches Hold down MENU button to Exit Switch 1 temp 84 Vp 0 30 48 Reading lt gt Control 142 O A 11 181 Vertical Scale ee 000000 190 24 EEE 0000000000000000000000000000 Figure 6 7 Front Panel Diagnostic Display 11 Rotate the d gt POSITION control slowly in either direction The bar graph shown on the display represents the two elements of each control The readings to the right of the bar graph represent numbers used by the instrument to calculate the
245. ously at the display 1 624 ft lt gt Accumulated 1 eee Jitter Figure 2 16 Jitter Captured Using Max Hold If the Instrument failed Jitter or Risetime checks 1t 15 probably still adequate for all but extremely precise distance measurements If it failed Horizontal Scale check you should not use the instrument until the cause of the failure has been identified and corrected All of the previous checks only test the major functional blocks of the instrument that could prevent you from being able to make measurements It is possible for the front panel controls or the LCD to have problems that would interfere with controlling or displaying measurements Most problems of this type would become evident as you perform the checks If you suspect a problem of this nature you should have the instrument checked by a qualified service technician using the diagnostics in the 502B Service Manual If the instrument passed all of the previous checks it is ready for use 1502B MTDR Service Manual Specifications The tables in this chapter list the characteristics and features that apply to this instrument after it has had a warm up period of at least five minutes The Performance Requirement column describes the limits of the Characteristic Supplemental Information describes features and typical values or other helpful information Electrical Characteristics
246. owing table for tolerances 2030 T1030 R2025 4 R2026 2021 MNT Q2030 Q2022 02031 5 CR2030 R2027 203 ES C2024 2030 O Figure 6 42 Power Supply Test Point TP2030 Supply Range Test Point Location 16 2 VDC 115 9 to 16 4 VDC TP2030 Power Supply Board 15 0 VDC 4 85 to 45 25 VDC Pin 1 5040 Main Board 5 0 VDC 4 85 to 5 25 VDC Pin 3 5040 Main Board 15 0 VDC 114 7 to 415 3 VDC Pin 4 5040 Main Board 15 0 VDC 14 7 to 15 3 VDC Pin 6 5040 Main Board 7 Make a mental note of the location where the ribbon cable from the power supply is plugged into the Main Board then turn the instrument over NOTE When the instrument is turned over you will be looking at the top component side of the Main Board The J5040 pins go through the circuit board and appear on the top component side of the Main Board J5040 P5040 is the input from the power supply The other end of the cable is J1030 P1030 on the Power Supply Board Measure the voltages on the pins listed in the table and verify the supply voltages 6 27 Calibration 6 28 Range Check 14 2 1 13 DC C x w OC IN 1 2 14 eae plug P5040 Connector pin J5040 on bottom of Main Board
247. positioning of the displayed waveform 1502B MTDR Service Manual 5 13 Circuit Descriptions 5 14 Vertical Position DAC Summing Amplifier Video Amplifier The combined video and position signal is amplified by the user selected gain in the video amplifier Gain of the amplifier is set by the processor system via the data bus and video amplifier select signal The amplified video is digitized by the video ADC upon receipt of a control signal from the processor system The processor is notified by the ADC interrupt request when the conversion has been completed The processor then reads the value via the data bus The vertical position DC voltage is generated by a digital to analog converter consisting if U2046 and 03041 DAC integrated circuit 02046 receives a 2 5 VDC reference voltage from U3040 and multiplies it by a 14 bit digital value loaded from the data bus under control of the processor The resulting current output of U2046 is amplified by operational amplifier U3041 to a proportional voltage of zero to 2 5 VDC The summing amplifier consists of operational amplifier U8041 input resistors R8044 8046 and R8047 and a feedback resistor R8045 Summation of the DAC output through R8047 with the 2 5 VDC reference through R8046 causes the vertical position signal range to be enlarged and shifted to achieve an effective output of 2 5 VDC to 42 5 VDC Sampled video through R8044 is summed with the vertical position
248. pping container is damaged notify the carrier as well as Tektronix The instrument was inspected both mechanically and electrically before shipment It should be free if mechanical damage and meet or exceed all electrical specifications Procedures to check operational performance are in the Performance Checks appendix These checks should satisfy the requirements for most receiving or incoming inspections The 1502B is intended to be operated from a power source that will not apply more than 250 volts RMS between the supply conductors or between either supply conductor and ground A protective ground connection by way of the grounding conductor in the power cord is essential for safe operation The AC power connector is a three way polarized plug with the ground earth lead connected directly to the instrument frame to provide electrical shock protection If the unit is connected to any other power source the unit frame must be connected to earth ground Power and voltage requirements are printed on the back panel The 1502B can be operated from either 115 VAC or 230 VAC nominal line voltage at 45 Hz to 440 Hz or a 12 VDC supply or a battery pack Further information on the 1502B power requirements can be found in the Safety Summary in this section and in the Operating Instructions chapter When the 1502B is to be shipped to a Tektronix Service Center for service or repair attach a tag showing the name and address of the owner name o
249. properly 1502B MTDR Service Manual Calibration 1 Inthe Service Diagnostic Menu select the RAM ROM Diagnostics Exit Service Diagnostic Menu Sampling Efficiency Diagnostic Noise Diagnostic Impedance Diagnostic Offset G ain Diagnostic RAM ROM Diagnostics Timebase is Normal Auto Correction Move Position to select then push MENU button Figure 6 27 Service Diagnostic Menu 2 Press MENU The diagnostic is automatic and will display the result on the LCD 3 Turn the instrument off then on again This will reset it for the next check NOTE If the instrument fails any of the last three checks refer to the Circuit Descriptions chapter and the Troubleshooting section of the Maintenance chapter of this manual Aberrations Check If the aberrations are out of spec the ohms at cursor function might be less accurate than specified 1 Set the front panel controls CABLE 50Q terminator NOISE FILTER avg VERT SCALE 500 mp DIST DIV 5 ft div Vp 99 2 Using the POSITION control adjust the distance window to read 2 000 ft 1502B MTDR Service Manual 6 17 Calibration 6 18 WWE F F Figure 6 28 Waveform with Cursor at 2 000 ft 3 Increase DIST DIV to 50 mp div 4 Center the pulse on the display keeping the trailing baseline on the center graticule ac 1 160 ft nno Figure 6 29 Waveform at 50 mp div 5 Setthe
250. ption CKT BD ASSY S R DRIVER SAMPLER Con t RES FXD FILM 30 OHM 5 0 25W RES FXD FILM 10K OHM 5 0 25W RES FXD FILM 100 OHM 5 0 25W RES FXD FILM 510 OHM 596 0 25W RES FXD FILM 100 OHM 5 0 25W RES FXD FILM 100 OHM 5 0 25W RES FXD FILM 120 OHM 5 0 25W RES FXD FILM 47K OHM 5 0 25W RES FXD FILM 24K OHM 5 0 25W RES FXD FILM 100 OHM 5 0 25W RES FXD FILM 5 6K OHM 5 0 25W RES FXD FILM 100 OHM 5 0 25W RES FXD FILM 20K OHM 5 0 25W RES FXD FILM 100 OHM 5 0 25W RES FXD FILM 5 6K OHM 5 0 25W RES FXD FILM 7 5K OHM 5 0 25W RES FXD FILM 10 OHM 5 0 25W RES FXD FILM 37 4K OHM 1 0 2W RES FXD CMPSN 2 7 OHM 5 0 125W RES FXD CMPSN 2 7 OHM 5 0 125W RES FXD FILM 6 04K OHM 1 0 2W RES FXD FILM 10 OHM 5 0 25W RES FXD FILM 10 OHM 5 0 25W RES FXD FILM 130K OHM 1 0 2W RES FXD FILM 12 5K OHM 0 25 0 125W RES FXD FILM 110K OHM 0 25 0 2W RES FXD FILM 100K OHM 0 5 0 125W RES FXD FILM 100K OHM 0 5 0 125W XFMR TOROID 2 WINDINGS 067 0572 00 Mfr Code 01121 01121 01121 01121 01121 01121 01121 01121 01121 01121 01121 01121 01121 01121 01121 01121 01121 57668 01121 01121 57668 01121 01121 57668 01121 56845 19701 19701 0 R03 Mfr Part Number CB3005 CB1035 CB1015 CB5115 CB1015 CB1015 CB1215 CB4735 CB2435 CB1015 CB5625 CB1015 CB2035 CB1015 CB5625 7525 1005 2 FXE 37 4 BB2765 BB2765 CRB20 FXE 6K04 CB1005 CB1005 CRB20 FXE 130K ADVISE CCF 50 2 1103F 5033R C1
251. rce drawing current from the 15 8 VDC and supplying it to the battery through T2012 The voltage drop across T2012 is fed back to U2010 through diode CR2014 to control charging current at anominal 150 mA Diode CR2013 and voltage divider R2010 and R2011 provide a voltage clamp to U2010 s feedback terminal to limit the maximum voltage that can be applied to the battery through CR2015 As the voltage R2012 and CR2015 approaches the clamp voltage battery charging current is gradually reduced to trickle charge Rectifier CR2015 prevents battery discharge through the charger when AC line voltage is not present Rectifier CR2012 allows the battery pack to power the instrument when AC power is not present Pre regulator or battery voltage is applied to Q2011 and Q2012 when the instrument power switch is pulled on The rising voltage causes Q2011 and Q2012 to turn on due to the momentary low gate voltage while C2011 is charging During this time voltage comparator U1020A compares the switched voltage to a 42 5 VDC reference from U1022 If the voltage is greater than 9 7 VDC U1020A turns on drawing current through Q2010 and R2015 to keep the gates of Q2011 and Q2012 near ground and the transistors turned on If the voltage is less than 49 7 VDC drops to that value later U1020A 02010 turn off allowing C2011 to charge to the input voltage and turn off Q2011 and Q2012 When turned off the deep discharge protection circuit limits current draw
252. rence between the two regulators The synchronizing signal from U1023 is also supplied to Q2021 where it is amplified to CMOS levels and buffered by gate U2030A The signal is then used to clock flip flop U1024B to produce 40 kHz square wave output at Q and Q These square waves are buffered by other U2030 inverters and used to drive DC to DC transistors 02030 and 02031 Transistors 02030 and Q2031 apply push pull power to the primary of T1030 at 40 kHz by switching the 16 2 VDC alternately between the primary windings The resulting transformer secondary voltages are rectified and filtered by CR1034 C1032 C1033 and C1034 to produce 15 VDC and 15 VDC Other secondary voltages are rectified and filtered by CR1030 CR1031 CR1032 CR1033 C1030 C1031 and C1037 to produce 5 VDC and 5 VDC Diodes CR2031 and CR2030 rectify the primary voltage and clamp it to the voltage level that is across C2031 This prevents voltage transients caused by the rapid switching of Q2030 and Q2031 and prevents the leakage inductance of T1030 s primary from creating excessive voltage stress R2030 provides a discharge path from C2031 T1031 and C1036 provide additional filtering of the 16 VDC supply The processor system consists of the following m Microprocessor m Address Decoding and Memory m Interrupt Logic 5 7 Circuit Descriptions 5 8 Microprocessor The processor system provides control and calculation functions for the Instrumen
253. rols NOISE FILTER 1 avg 3rd stop CW DIST DIV ft div 4th stop CW Vp 99 Make sure the POWER switch is in the OFF position Connect the 115 VAC output of the Variac into the AC socket on the rear of the 1502B 6 25 Calibration Voltage Checks 1 Pullthe POWER switch to the ON position 2 Observe that the power draw does not exceed 4 Watts on the Variac Power Supply Board Figure 6 40 Power Supply Board 3 Connect the positive voltmeter probe to TP1020 16 6 VDC it might be marked as 15 8 V on some older power supplies 4 Connect the negative probe to TP1010 ground C mo R1016 O 02 U1010 U1011 OLOT f 1010 CR1010 C1012 C1013 01010 01011 1 R1014 r CR101 11010 2010 1012 Figure 6 41 Power Supply Test Points 1020 and 1010 6 26 1502B MTDR Service Manual Calibration 1502B MTDR Service Manual S Verify that the supply voltage is 16 6 VDC and there is a minimal current drawn 2W from the Variac 6 Connect the positive voltmeter probe to TP2030 The negative voltmeter probe should remain connected to ground The reading should be 16 2 VDC see foll
254. s are covered by U S and foreign patents issued and pending TEKTRONIX and TEK are registered trademarks of Tektronix Inc FCC Class A Device This equipment has been tested and found to comply with the limits for a Class A digital device pursuant to Part 15 of the FCC Rules These limits are designed to provide reasonable protection against harmful interference in a commercial environment This equipment generated uses and can radiate radio frequency energy and if not installed and used in accordance with the instructions may cause harmful interference to radio communications Op eration of this equipment in a residential area is likely to cause harmful interfer ence in which case the user will be required to correct the interference at his own expense Changes or modification not expressly approved by Tektronix can affect emission compliance and could void the user s authority to operate this equipment The 1502B Metallic Time Domain Reflectometer was designed and manufactured by Tektronix Inc 100 S E Wilson Ave Bend Oregon 97702 U S A Phone 1 800 835 9433 Certificate of the Manufacturer Importer We hereby certify that the Tektronix 1502B Metallic complies with the RF Interference Suppression requirements of Amtsbl Vfg 1046 1984 The German Postal Service was notified that the equipment is being marketed The German Postal Service has the right to re test the series and to verify that it complies TEK
255. scriptions 10 2 Lists Battery Pack 10 15 Case 10 5 Frame 10 8 Front Panel 10 8 Power Supply 10 13 Mfr Code 10 2 10 3 Parts Ordering Information 10 1 Using the Lists 10 1 Return Loss 1 15 1 16 safety Covers x Explosive Atmosphere x Grounding x Symbols ix erminology ix safety Summary xi salt Atmosphere Spec 3 3 Sand and Dust Spec 3 3 Scale see Controls Service Manual 4 3 Ship Carton Strength xv Shock Spec 3 3 Short 1 13 single Sweep 1 27 Slide Rule 4 2 Specifications 3 1 Electrical 3 1 Environmental 3 3 Physical 3 4 Store the Waveform 1 13 I Temperature Low 1 4 Terminator 4 2 1502B MTDR Service Manual Index U Unpacking xiv V Velocity of Propagation 1 10 Table of Types 1 10 Unknown Vp 1 11 Velocity of Propagation See also Controls 1 6 Vertical Set Reference 1 23 Vibration Spec 3 3 1502B MTDR Service Manual View Difference 1 19 View Input 1 17 View Store 1 18 Voltage see Power Voltage Spec 3 2 Vp see Velocity of Propagation W Water Resistance Spec 3 3 Wavetorm Storage 1 18 Weight Spec 3 4 Index 5 Index Index 6 1502B MTDR Service Manual
256. sor and combined with the formatted sample waveform before it is sent to the display 9 3 Circuit Descriptions Power Supply 115 230 volt AC line Introduction The power supply consists of the following Primary Circuit Pre regulator Battery Charger Deep Discharge Protection Port regulator DC to DC Converters The power supply converts either 115 230 VAC line power or takes power from a nickel cadmium battery pack and provides the instrument with regulated DC voltages A block diagram of the power supply is shown in Figure 5 3 Instr P wr Fuse and Rectif Switch ind js De det Step down SU 430VDC PUE 415 8 VDC A Filter Switch XFMR Filter Cap Prereq Battery Charger Batte 12 VDC Pack gt 10 to 15 5 VDC Transistor Power Switch Switcherand 16 2 VDC 16 voc N Post regulator 2 DC Power DC to DC gt tp Instrument Converter gt L15VDC DD Deep Discharge Protection Power Status Figure 5 3 Power Supply Block Diagram Single phase AC line voltage is applied to the power supply module through a power plug with internal EMI filter The filtered line voltage is immediately fused routed through a line selector switch and applied to a stepdown transformer The transformer secondar
257. st Adjust is set properly you will be able to see the cursor clearly when itis moved rapidly across the display If any residual images are made by the cursor movement they should fade out quickly NOTE If you are unable to adjust the contrast or if pixels are not functioning see the Troubleshooting section in the Maintenance chapter of this manual The following adjustment is located on the Driver Sampler Board 1 2 I Figure 6 62 Driver Sampler Board Location Turn off the POWER to the instrument Remove the EMI shield covering the Driver Sampler Board see Maintenance chapter Turn the POWER on Adjust the POSITION control until the distance window reads 2 000 ft Adjust the control to center the baseline on the center horizontal graticule line see Figure 6 63 next page Set the front panel controls CABLE no connection NOISE FILTER 1 avg VERT SCALE 10 mp DIST DIV 0 2 ft div Vp 99 1502B MTDR Service Manual Calibration 1502B MTDR Service Manual x Figure 6 63 Incident Pulse at 2 000 ft 7 If necessary readjust the POSITION control to center the baseline on the center horizontal graticule line 8 Attach the 3 foot precision cable to the front panel CABLE connector This will probably cause the waveform to move slightly on the display 9 Adjust R1042 Zero Offset to move the waveform to the same position as w
258. t F Figure 6 21 Waveform at Centered If the instrument fails this check refer to the Troubleshooting section of the Maintenance chapter of this manual If the instrument fails this check it might still be usable for measurements of large faults that do not require a lot of gain A great deal of noise reduction is available with the NOISE FILTER control 1 Setthe front panel controls CABLE 50Q terminator NOISE FILTER avg VERT SCALE 500 mp DIST DIV 10 ft div Vp 99 6 13 Calibration 6 14 2 Turn the POSITION control until the distance window reads 100 000 ft 0 F F Figure 6 22 Cursor Moved to 100 000 ft 3 Chanee DIST DIV to 0 1 ft div 4 Using the VERT SCALE control set the gain to 5 00 mp div 5 Use the POSITION control to keep the waveform centered on the display S s D F Figure 6 23 Noise with Gain at 5 00 mp Press MENU Using POSITION control scroll to Diagnostics Menu Press MENU again Using the same procedure select Service Diagnostic Menu then Noise Diagnostic 10 Read the results on the display 1502B MTDR Service Manual Calibration Noise Diagnostic Continuous Result Update Acceptable Range Result 0 11 Pixels 4 vertical scale at 5 00 and cursor at location to sample Push MENU button to Exit
259. t A block diagram of the processor system is shown in Figure 5 4 An eight bit microprocessor clocked at 5 MHz provides the processing capability in a bus organized system Instructions are read from the program memory EPROM and executed by the microprocessor to accomplish essentially all instrument functions Random access memory 15 connected to the microprocessor through its data and address busses allowing it to store and retrieve control video and display data as required 5 MHz CLOCK DATA INTERRUPT MICROPROCESSOR m PROGRAM MEMORY INTERRUPT AND EPROM STATUS INPUTS N gt ACCESS lt 2 MEMORY lt MN DATA SELECT AND ADDRESS SELECT ADDRESS SIGNALS m DECODING gt TO CIRCUITS AND OPTIONS PORT gt Figure 5 4 Processor Block Diagram The processor communicates with all other instrument circuits via the address data and select signals and receives requests for service from those circuits via the interrupt and status signals Select signals are generated in address decoding circuits under control of the processor and used to read or write data from a circuit or to trigger a circuit function Interrupts from those circuits are combined in the interrupt logic to generate an interrupt request to the microprocessor The processor responds by reading a data word from this logic to determine the source of the int
260. t integrity of the instrument will be compromised Tek Part No Sealant Comments 006 2302 00 Dow Corning 3145 Adhesive Sealant Use to secure rubber boot around buttons implosion shield to front panel 252 0199 00 Dow Corning 3140 Coating Use to secure case gaskets to chassis more fluid sealant than 3145 with 24 hour cure time 006 2207 00 GE G 661 Silicon Grease Light coating on case gaskets to pre vent sticking and provide a good seal 006 0034 00 Isopropyl alcohol Cleaning agent If a rubber boot or gasket is replaced 1 Remove the old gasket 2 Remove all dried adhesive 3 Clean area with alcohol and let dry 1502B MTDR Service Manual Maintenance 4 Runasmall bead of 3140 Coating Adhesive in the cutout where the new gasket will go 5 Smooth the adhesive into an even thin layer 6 Clean the new gasket with alcohol and let dry 7 Placethe gasket on the adhesive and smooth into place Make sure the edges are secure and there are no air bubbles under the gasket 8 Let dry for 24 hours before using or reassembling the front panel 9 Use silicon grease on the outer side of the front panel gasket and the battery gasket where they contact the instrument case The instrument rotary controls the fuse and line voltage select access covers are sealed with rubber O rings These are not glued in place but should be inspected and replaced if necessary Top and Bottom EMI Shield Installation 1 Place
261. tenance Removing the Front Panel Board from the Display 7 12 Module 3 Remove the hex nuts and washers from the front panel controls 4 Remove the buttons by pressing gently on the rubber boot behind each button CAUTION Take care not to use a sharp object to remove the buttons because it might puncture the rubber boot thereby subjecting the instrument to moisture water intrusion NOTE When re assembling push the rubber boot down on the switch shaft so that the switch button can easily be replaced 5 Remove the four screws holding the Display Module Front Panel Board to the front panel see Figure 7 9 dc gt Figure 7 9 Display Module Front Panel Board Screw Locations 6 Carefully lift the Display Module Front Panel Board from the front panel T Remove the four hex nuts two are shown in Figure 7 10 next page that hold the Display Module to the Front Panel Board 2 Disconnect the ribbon cable from the boards 3 Carefully separate the Display Module from the Front Panel Board 1502B MTDR Service Manual Maintenance a 4 Figure 7 10 Display Module Front Panel Board Showing Hex Nuts CAUTION Do not further disassemble the Display Modu
262. tenance chapter of this manual If the instrument fails this check you might still make some tests but the offset might change when cable conditions change 1 Set the front panel controls CABLE see below NOISE FILTER 1 avg VERT SCALE 500 mp DIST DIV 2 ft div Vp 99 POWER ON Nothing should be connected to the front panel CABLE connector 2 Adjust the gt POSITION control so the distance window reads 2 000 ft 3 Use the POSITION control to center the baseline before the incident pulse 4 Increase VERT SCALE to 10 mp using the SPOSITION control to keep the baseline centered on the display 1502B MTDR Service Manual Calibration mas x Figure 6 16 Incident Pulse at 2 000 ft 5 Thefront panel CABLE connector has a shorting bar that shorts the input when a cable is removed Attach the 3 ft precision cable to the CABLE connector to defeat this shorting bar 6 Notice any minor changes in the waveform The waveform prior to the leading edge might change shape slightly but should not shift more than one division Figure 6 17 Incident Pulse at 2 000 ft with 3 ft Cable Connected Max Hold can be used to easily monitor any changes as shown below F F Figure 6 18 Incident Pulse at 2 000 ft with Max Hold 7 Turn the instrument OFF then ON again This will reset it for the next check 1502B MTDR Service Manual
263. th mild soap and water The faceplate in front of the LCD should be cleaned gently with Kendall Webril non woven wipes Tek P N 006 0164 00 or equivalent moistened with isopropyl alcohol Maintenance Lubrication Visual Inspection Recalibration The interior of the 1502B is protected from dirt and dust as long as the option port and case are intact However if interior cleaning is necessary blow off accumulated dust with low pressure air and remove the remaining dirt with a soft brush cotton swab or pipe cleaner moistened with isopropyl alcohol All the switches and potentiometers on the 1502B are sealed from external contaminants and therefore require little maintenance and no lubrication Occasionally blowing out accumulated dust is all that is needed Obvious defects such as broken connections damaged boards frayed cables improperly seated components and heat damaged components should be corrected first before attempting further troubleshooting Heat damage usually indicates a deeper problem somewhere in the circuitry and should be traced and corrected immediately We do notrecommend electrical checks of individual components because defective components will become evident during instrument operation After maintenance has been performed the instrument should be checked as per the procedures in the Calibration chapter of this manual Part Removal and Replacement 7 2 Fuse The fuse 1s accessi
264. the 1502B for testing 2 NOISE FILTER If the displayed waveform is noisy the apparent noise can be reduced by using noise averaging Averaging settings are between 1 and 128 The time for averaging is directly proportional to the averaging setting chosen A setting of 128 might take the instrument up to 35 seconds to acquire and display a waveform The first two positions on the NOISE FILTER control are used for setting the vertical and horizontal reference points The selected value or function is displayed above the control on the LCD Operating Instructions VERT SCALE 3 VERT SCALE This control sets the vertical sensitivity displayed in per division or the vertical gain displayed in dB Although the instrument defaults to millirho you may choose the preferred mode from the Setup Menu The selected value is displayed above the control on the LCD 4 DIST DIV Determines the number of feet or meters per division across the DIST DIV display The minimum setting is 0 1 ft div 0 025 meters and the maximum setting 1s 200 ft div 50 meters The selected value is displayed above the control on the LCD A standard instrument defaults to ft div A metric instrument Option 05 defaults to m div but either may be changed temporarily from the menu The default can be changed by changing an internal jumper see 502B Service Manual and always refer such changes to qualified service personnel Vp 5 Vp The two Velocity
265. the incident electrical energy The pulse of electrical energy sent out by the TDR The waveform shown by the TDR consists of this pulse and the reflections of it coming back from the cable or circuit being tested see Reactance 1502B MTDR Service Manual Glossary Insulation Jitter LCD Millirho Noise 1502B MTDR Service Manual A protective coating on an electrical conductor that will not readily allow electrical energy to flow away from the conductive part of the cable or circuit Insulation is also called dielectric The kind of dielectric used in a cable determines how fast electricity can travel through the cable see Velocity of Propagation The short term error or uncertainty in the clock timebase of a TDR If the timing from sample to sample is not exact the waveform will appear to move back and forth rapidly An acronym for Liquid Crystal Display It is the kind of display used on this instrument so the terms display and LCD are often used interchangeably rho is the reflection coefficient of a cable or power delivery system It is the ratio of the voltage reflected back from the cable or circuit due to cable faults or an impedance mismatch at the load divided by the voltage applied to the cable Millirho are thousandths of one rho Rho measurements are often used to judge how well the cable is matched to the load at the other end of the cable If there is an open circuit in the cable nearly all the
266. trument without removing the case When AC power is applied the battery pack is charged at a continuous rate of approximately 150 mA The battery pack will operate the 1502B for a minimum of five continuous hours including making 20 chart recordings if the LCD backlight is turned off The battery pack will charge fully in 16 hours when the instrument is connected via the power cord to an AC power source with the instrument turned off The instrument may be turned on and operated while the batteries are charging but this will increase the charging time For longest battery life a full charge is preferred over a partial charge For maximum capacity the batteries should be charged within a temperature range of 4 20 C to 4 25 C However the batteries can be charged within a temperature range of 0 C to 40 C and operated in temperatures ranging from 15 C to 455 1502B MTDR Service Manual Operating Instructions Low Battery 1502B MTDR Service Manual CAUTION Do not charge battery pack below 0 C or above 45 C Do not discharge battery pack below 20 C or above 65 C If removing the battery pack during or after exposure to these extreme conditions turn the instrument off and remove the power cord Move the instrument to ignition free area before removing the battery pack If the instrument is operated beyond the previously stated limits turn off the instrument and either disconnect the AC power or
267. ts 8 2 Tektronix Part No Serial Model No Name and Description Mfg Code Mfg Part Number Column 2 This column lists the part number used when ordering a replacement part from Tektronix Columns 3 and 4 Column 3 lists the serial number of the first instrument or the suffix number of the circuit board in which the part was used Column 4 lists the serial number of the last instrument or the suffix number of the circuit board in which the part was used No entry indicates that the part is used in all instruments Column 5 In this parts list the item name is separated from its description by a colon Because of space limitations the item name may appear to be incomplete For further item name identification refer to the U S Federal Cataloging Handbook H6 1 Column 6 This column lists the code number of the manufacturer of the part Column 7 This column lists the manufacturer s part number 1502B MTDR Service Manual Replaceable Electrical Parts Manufacturers Cross Index Mfr Code 01002 01121 01295 01686 02111 03508 04222 04426 04713 07716 09922 0B0A9 0 985 0 R03 0 R04 10392 12697 12954 12969 13409 14433 14552 14936 Manufacturer GENERAL ELECTRIC CO CAPACITOR PRODUCTS DEPT ALLEN BRADLEY CO TEXAS INSTRUMENTS INC SEMICONDUCTOR GROUP RCL ELECTRONICS SHALLCROSS INC SUB OF HIRSCH AND ASSOCIATES INC HAMILTON STANDARD CON
268. ual Inspection To perform the Adjustment Procedure the instrument must be removed from the case and the EMI shields removed Instructions on both procedures are located in the Maintenance chapter of this manual If any repairs are made to the instrument or if it has been disassembled we recommend a visual inspection be made 1 Check all screws for tightness and that the screw heads are not burred or rounded Set the line voltage switch on the rear panel to 110V and check for the proper fuse 0 3 A Check if the LCD has been cleaned on the outside and the Implosion shield of the front panel has been cleaned on the inside Check that the knobs and buttons work properly The NOISE FILTER DIST DIV and both Vp knobs have detents all others should rotate smoothly Check that the knobs are tight no loose set screws Check that the set screw on the POWER switch shaft 15 tight Check the cables for proper connection polarity and tightness Make sure the cables on the front of the Main Board come down from the plug into the instrument instead of curving toward the outside All cables should have the exposed ends away from the metal chassis If any components were replaced by soldering check for solder balls excess flux and wire clippings Good soldering practices must be followed when repairing this instrument Power Supply Checks and Adjustments Power Up Procedure 1502B MTDR Service Manual 1 Set the front panel cont
269. uit Number Number Number Read resistor 1234 of subassembly 2 of assy 23 Only circuit numbers appear on the schematics circuit board illustrations and electrical parts locator lists Each schematic and illustration is marked with its assembly number Assembly numbers are also marked on the mechanical exploded view located in the replaceable mechanical parts list A component number is obtained by adding the assembly number prefix to the circuit number The component number may then be used to reference a part in the replaceable electrical parts list 1502B MTDR Service Manual Diagrams Refer to Internal diagram 3A Test point adjustment A B C D VCCV R40330 eel 180 8 9V R40340 3 32 PHASE NULL 192k TP4g3g5 U40311A 4 74ACT74 R40333 4 332 SMPL LOCK 5 S VCO TUNE 1 440135 51 TL 34081 40312 40331 C40329 1 3 040313 1 74F 00 3 o wr ud C40338 1 1uF R49342 40345 100 9 14 12V i 100 Connector 40306 U40311B to 3D PULS Lock 74 74 R40336 R40335 R40339 3 92k 3 92k 20 Q Q PLock FF Q D CLR 2 Instrument type VCCV VCCV VCCV C40330 C4034Q FiberMaster C40342 luF 1uF Board CONTROL Functional
270. ument refers to the amount of voltage gain amplification the instrument applies to the signal before displaying it For example when the instrument is amplifying the voltage by one hundred the dB scale would read 40 dB which is 20 log 100 Direct current is a method of delivering electrical energy by maintaining a constant flow of electrons in one direction Even circuits designed to generate only AC often have a DC component see Insulation A mathematical term that refers to the set of numbers that can be put into a function the set of numbers that comes out of the function is called the A time domain instrument performs its function by measuring time The total opposition to the flow of electrical energy is a cable or circuit Impedance is made partly of resistance frequency independent and partly of reactance frequency dependent Although impedance is expressed in units of Ohms it must not be confused with the simple resistance that only applies to DC signals Technically impedance is a function of the frequency of the electrical signal so it should be specified at a frequency As a practical matter the impedance of most cables changes very little over the range of frequencies they are designed for A point in a cable or system where the incident electrical energy is redistributed into absorbed reflected and or transmitted electrical energy The transmitted electrical energy after the mismatch 1s less than
271. until the cursor rests on the leading edge of the rising or falling reflected pulse see Figure 1 10 Read the distance in the distance window in the upper right corner of the display A more thorough inspection might be required This example uses a longer cable 4 When inspecting a 452 foot cable a setting of 50 ft div allows a relatively fast inspection If needed turn VERT SCALE to increase the gain The higher the gain the smaller the faults that can be detected If noise increases increase the NOISE FILTER setting 1 13 Operating Instructions 1 14 Reflection Coefficient Measurements 1 1 452 000 ft Figure 1 11 455 ft Cable 5 Change DIST DIV to 20 ft div The entire cable can now be inspected in detail on the LCD Turn the lt POSITION control so the cursor travels to the far right side of the LCD Keep turning and the cable will be dragged across the display 1 i 452 000 ft Short Figure 1 12 455 ft Cable A rise or fall is a signature of an impedance mismatch fault A dramatic rise in the pulse indicates and open A dramatic lowering of the pulse indicates a short Variations such as inductive and capacitive effects on the cable will appears as bumps and dips in the waveform Capacitive faults appear as a lowering of the pulse e g water in the cable Inductive faults appear as a rising of the pulse e g fray Wh
272. veform e III 8000007 ew stone VIEW STORE 4 Current Waveform VIEW INPUT Difference MIEW DIFF Figure 1 21 Current Waveform Center Stored Waveform Above Difference Below Notice the VIEW INPUT waveform 15 solid VIEW DIFF is dotted and VIEW STORE is dot dash There are many situations where the VIEW DIFF function can be useful One common situation is to store the waveform of a suspect cable repair the cable then compare the two waveforms after the repair During repairs the VIEW INPUT VIEW DIFF and VIEW STORE waveforms can be used to judge the effectiveness of the repairs The optional chart recorder can be used to make a chart of the three waveforms to document the repair Another valuable use for the VIEW DIFF function is for verifying cable integrity before and after servicing or periodic maintenance that requires moving or disconnecting the cable The VIEW DIFF function is useful when you want to see any changes in the cable In some systems there might be several reflections coming back from each branch of the network It might become necessary to disconnect branch lines from the cable under test to determine whether a waveform represents a physical fault or is simply an echo from one of the branches The STORE and VIEW DIFF functions allow you 1502B MTDR Service Manual Operating Instructions Using Horizontal Set Reference 1502B MTDR Service Manual to see and compare the network wit
273. vious paragraphs Vp 1 Setthe 1502B controls POWER On CABLE Cable to BNC NOISE FILTER avg VERT SCALE 500 mp DIST DIV see below Vp per cable 2 If you know approximately how long the cable is set the DIST DIV appropriately e g 20 ft cable would occupy four divisions on the LCD if 5 ft div was used The entire cable should be displayed Figure 1 8 20 8 Cable at 5 ft div If the cable length is unknown set DIST DIV to 200 ft div and continue to decrease the setting until the reflected pulse is visible Depending on the cable length and the amount of pulse energy absorbed by the cable it might be necessary to increase the VERT SCALE to provide more gain to see the reflected pulse 1 12 1502B MTDR Service Manual Operating Instructions 1502B MTDR Service Manual 1 1 i1 20 000 ft Short Figure 1 9 Short in the Cable When the entire cable is displayed you can tell if there is an open or a short Essentially a large downward pulse indicates a short see Figure 1 9 while a large upward pulse indicates an open see Figure 1 10 Less catastrophic faults can bee seen as smaller reflections Bends and kinks frays water and interweaving all have distinctive signatures a i ho 20 000 ft Open Figure 1 10 Open in the Cable 3 find the distance to the fault or end of the cable turn the gt POSITION control
274. w the horizontal scale is displayed You may choose from feet per division or meters per division When powered up the instrument will default to feet unless the internal jumper has been moved to the meters position Instructions on changing this default are contained in the 502 Service Manual Light Is On Off This control turns the electroluminescent backlight behind the LCD on or off S Diagnostics Menu lists an extensive selection of diagnostics to test the operation of the instrument NOTE The Diagnostics Menu is intended for instrument repair and calibration Proper instrument setup is important for correct diagnostics results Refer to the 1502 Service Manual for more information on diagnostics a Service Diagnostics Menu has these choices i Sampling Efficiency Diagnostic displays a continuous efficiency diagnostic of the sampling circuits ii Noise Diagnostic measures the internal RMS noise levels of the instrument Hi Offset Gain Diagnostic reports out of tolerance steps in the program mable gain stage This can help a service technician to quickly isolate the cause of waveform distortion problems iv RAM ROM Diagnostics Menu performs tests on the RAM Random Access Memory and the ROM Read Only Memory v Timebase Is Normal Auto Correction Diagnostic No Correction When in Normal Auto Correction the instrument compensates for variations in temperature and voltage This condition might not be d
275. y The processor adjusts the reference for the timebase DAC so as to sample at the previous level This matches the analog delay to the 50 ns period of the clock 1502B MTDR Service Manual Tenuen 9514195 YALIN 0 1 61 6 Bojeuy 06 pue 0197 Jo uoneiqi e LL 6 aniy 20 MHz CLK 50 ns TP2031 PULSE TRIG DIGITAL DELAY TRIG TO PULSE GEN TP9011 TRIG TO SAMPLER TP7010 SAMPLE TRIG TP2030 START PULSE VAR DELAY RAMP TO SET DELAY ZERO A DELAY ZERO SET bu COMPARATOR LEVEL SET SO SAMPLE TAKEN AT 10 POINT ON OUTPUT PULSE PULSE OUT 10 LEVEL Up 14 50ns DELAY COMPARATOR OUTPUT OV COMPARATOR LEVEL 0 DELAY Y 50 ns RAMP SET FIXED CIRCUIT DELAYS 50 ns RAMP START OV 0 DELAY 50 ns DELAY COMPARATOR LEVEL SET TO SAMPLE PULSE AT 10 POINT ON OUTPUT PULSE suonduos G Circuit Descriptions 5 20 Digital Timebase Analog Timebase All digital clocks from the Instrument are derived from a 20 MHz crystal oscillator 02031 Flip flops U2042A and U2042B divide the clock frequency to 10 MHz and 5 MHz respectively The 5 MHz output is provided to the microprocessor and to TP2041 Gate U2034B decodes one of the four states if U2042 and provides a 5 MHz pu
276. y voltage 15 rectified and power switched to power the post regulator 1502B MTDR Service Manual Circuit Descriptions Primary Circuit 1502B MTDR Service Manual A switching pre regulator reduces this voltage to 15 8 VDC and is used to power the battery charger This voltage is also processed through a rectifier and power switch to power the post regulator If a battery pack 15 installed the battery charger operates as a current source to provide a constant charging current Voltage limiting circuits in the charger prevent battery overcharge by reducing the charge current as the battery voltages approaches 12 5 VDC The battery pack consists of nine nickel cadmium C size cells connected in series This combination provides a terminal voltage of 10 to 12 5 VDC with a nominal capacity of up to 2 0 Amp Hours It also 15 connected through a rectifier to the instrument s power switch and post regulator When the power switch is closed an FET power transistor is momentarily turned on by the deep discharge protection circuit If the voltage to the post regulator rises to 49 7 VDC or greater the transistor switch remains on If at any time the voltage drops below 49 7 VDC the transistor turns off and the power switch must be recycled to restart the instrument This operation prevents discharge of the battery pack below 10 VDC Such a discharge could cause a reverse charge in a weak cell resulting in permanent cell damage The post

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