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Manual - Agilent Technologies

1. m 0 200 00 o oOo 0O02 0 0 0 0 Q DOP 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 C Cc 0 CO e amp ccc ee Oc COO SS O00 c a C CO OF O Onm c O 2 2 TASC gt 3 80 HP IB Address Model 8903B x Operation INDICATIONS As the numeric code is entered it will appear on the left display When the SPCL key is pressed the light within the key will turn on and all measurement key lights and annunciators will turn off If the 21 0 Special Function was entered the left display will show a binary number of the form AAAAA where AAAAA is the HP IB address in binary The right display will show a binary number of the form TLS where the T L and S have the meaning indicated in the table below LISTEN REQUESTING ONLY SERVICE LISTEN REQUESTING ONLY SERVICE If T and L are both 1 the instrument is set to talk only talk overrides listen If all the A digits are set to 1 and T is 1 the instrument will be in talk status only that is output the status byte only If all digits AAAAA TL are 1 but S is 0 the Remote Interface board is not installed If the 21 1 Special Function was entered the left display will show the statement ADDR and the right display will show the deci
2. 3 34 Sending the Status Bit Message 3 35 Receiving the Abort 3 35 HP IB Syntax and Characteristics Summary 3 35 AC Level er Be aE Rd ee ee Rw ae Se as Bee 3 42 oiu EC RE a eS OR OR ew Lu 3 44 Automatic Operalion cem Sw Sh oe EA Aw ep a OO Ge ar ae 3 46 Common s 2 969 dard reri eee SRE dde dog S Me Pe ewes eS 3 47 TC Level 5 ear taal Boras AO Be Ree ee ee 3 50 Default Conditions and Power up Sequence 3 52 Detector Selection moe E dodo m SSS OG Se BS AEE SS ox dod ew UM 3 53 Display Level m ob oe Re ded CIE A Reb EGS dcin dieu ees 3 55 Display Source Settings a cs y Sc ROS decem Ard NORD ee demo 3 57 Distortion 2 X uva 24 ee LS os PUR EE e OR E Ge eee UR eode 3 58 Distortion Level de reu a 3 60 Error Disable 62 ots 2 8 de We do onde dodo d 3 62 Error Message Summary oa e c ow ce OR cech ate e Role ded RR de drug ee 3 64 He A A Ea ee el eS See ee MP 3 68 ee et es ae 3 72 Freque
3. Model 8908 Performance Tests Table 4 1 Performance Test Record 6 of 12 RR AC LEVEL ACCURACY AND OUTPUT LEVEL ACCURACY AND FLATNESS PERFORMANCE TEST Synthesizer Displayed Frequency Reading of Step b Low Level High Input AC Level Accuracy 100 000 20 000 1 000 20 20 1 9 Output Level Accuracy 1 000 E ed Amplitude 20 000 50 000 100 000 100 000 50 000 20 000 1 000 20 20 1 000 20 000 50 000 100 000 100 000 20 000 1 000 20 20 1000 20 000 100 000 1 19 4 35 Performance Tests Model 8903B Table 4 1 Performance Test Record 7 of 12 Tesi ests OOO O No Minimum Actual Maxmum _ AC LEVEL ACCURACY AND OUTPUT LEVEL ACCURACY AND FLATNESS PERFORMANCE TEST Output Level Flatness _ o SOURCE v Ec HEN NE V 6 20 20 000 50 000 100 000 20 20 000 50 000 100 000 20 20 000 50 000 100 000 20 20 000 100 000 DC LEVEL ACCURACY PERFORMANCE TEST High Input DC Level Accuracy DC Standard Voltage 300 Vdc 297 Vdc 303 Vdc 30 Vdc 29 7 Vdc 3 Vdc 2 97 Vdc 0 6 Vdc 0 594 Vdc 0 06 Vdc 0 054 Vdc Low Input DC Level Accuracy DC Standard Voltage 0 06 Vdc 0 066 Vdc 0 6 Vdc 0 606 Vdc 3 Vdc 3 03 Vdc 30 Vdc 30 3 300 Vdc 303 Vdc
4. 3 22 Remote Operation Hewlett Packard Interface Bus 3 22 HPIBCoOmDaUDII oq age de eb OX UR go teri e Spe oe aa e Ee eot ei d 3 23 Remote Mode i3 9 es a f I Ed cat rs d ox CUR e d oe SSeS 3 23 MONG e RD de Mat do cie ecu UBL iE X e ie d cte eg D 3 23 Addresse 2 ese ase EO TO OC IT TT CTITCItt c 7T 51 1 117771 3 23 Data Messages reco SOROR Rn Web Ee dre OR diri ORT 3 26 Receiving the Data Message 3 3 ost GEAR e Werke ax uc E es 3 26 Sending the Data Message 3 30 Receiving the Clear Message 3 31 Receiving the Trigger Message 3 32 Receiving the Remote 3 32 Receiving the Local 3 33 Receiving the Local Lockout Message 3 33 Receiving the Clear Lockout Set Local Message 3 33 Receiving the Pass Control Message 3 33 Sending the Require Service Message 3 33 Selecting the Service Request 3 34 Sending the Status Byte Message
5. More than 255 points total in a sweep Although sweep resolution can be changed with Special Function 17 care should be taken to ensure that it will not result in more than 255 points in the total sweep Refer to Sweep Resolution HP IB only No signal sensed at input This error is sent on the HP IB when the display is shown 3 66 Error Message Summary Model 8903B Error Messages cont d Operation Error 20 Entered value out of Re enter new value range Invalid key sequence Check for compatibility of functions selected Invalid Special Function prefix Check then re enter correct Special Function code Refer to Special Functions Invalid Special Function suffix Invalid HP IB code Check then re enter correct Special Function code Refer to Special Functions Check then re enter correct HP IB code This error causes a Require Service message to be sent on the HP IB Refer to Table 3 4 and accompanying text 65 89 Refer to paragraph 8 12 Service Errors RELATED SECTIONS Automatic Operation Plot Limit RATIO and LOG LIN Sweep Resolution X Y Recording Error Message Summary 3 67 Model 8903B Filters Low Pass High Pass Bandpass DESCRIPTION The optional plug in high pass and weighting bandpass and the LP low pass FILTER keys cause the respective filters to be
6. Per BSTM 41004 20 to 55 80 relative humidity 60 Hz to 300 Hz 300 Hz to 3 kHz at 1 kHz 3 kHz to 3 5 kHz 3 5 kHz to 5 kHz CCIR Recommendation 486 2 averaging responding meter Dolby Labs bulletin No 19 4 20 to 55 8096 relative humidity 31 5 Hz to 63 Hz 63 Hz to 100 Hz 100 Hz to 200 Hz 200 Hz to 400 Hz 400 Hz to 800 Hz 800 Hz to 1 kHz 1 kHz to 6 3 kHz 6 3 kHz to 8 kHz CCIR ARM Weighting Filter Deviation from Ideal Response 30 88 1 19 General Information Model 8903B Tuble 1 1 Specifications 4 of 5 SYSTEM SPECIFICATIONS Cont d 0 4 dB 8 kHz to 9 kHz 0 6 dB 9 kHz to 10 kHz 0 8 dB 10 kHz to 12 5 kHz 1 2 12 5 kHz to 14 kHz i 1 65 dB 16 kHz to 20 kHz 2 0 dB 20 kHz to 31 5 kHz 2 8 inf dB at 31 5 kHz IEC Recommendation 179 and ANSI 1 4 type 1 sound level meter 20 to 55 C 80 relative humidity 20 Hz to 25 Hz 25 Hz to 31 5 kHz 31 5 Hz to 50 Hz 50 Hz to 4 kHz 4 kHz to 6 3 kHz 6 3 kHz to 8 kHz 8 kHz to 10 kHz 10 kHz to 12 5 kHz 12 5 Hz to 26 kHz A Weight Filter Deviation from Ideal Response 2 5 dB 2 0 dB 1 5 1 0 dB 1 5 2 0 dB 4 1 5 3 0 dB 2 0 4 0 dB 4 3 0 6 0 dB 3 0 inf dB TEMPERATURE Operating Storage 0 to 55 55 to 75 C Balanced Full differential I
7. Model 8903B 7 Set the Audio Analyzer source frequency to 1 kHz and establish a ratio reference in dB to the displayed value If the ac level is displayed in volts press the LOG LIN key to obtain a display in dB LOCAL keystrokes NOTE Since the RIAA amplifier gain is much higher at 20 Hz it is recommended that the signal source first be set to 20 Hz and the level set for less than rated output from the preamplifier 8 The graph paper is now scaled to measure ac level in dB from 20 Hz to 20 kHz The upper plot limit is equal to 4 30 dB and the lower plot limit is equal to 30 dB T he level at 1 kHz is referenced to 0 dB Press the SWEEP key to start the plot When the plot is completed the LED within the sweep key will turn off and the PEN LIFT output will go high If the plot has been disabled by Special Function 13 1 enable plot by keying in 13 0 SPCL PROGRAM CODES x The HP IB codes for the above example are given below START FREQ STOP FREQ AC LEVEL Hz kHz PLOT LIMIT UPPER LIMIT LOWER LIMIT RATIO Off RATIO On LOG SWEEP COMMENTS The X and Y axis outputs and the PEN LIFT output can be selectively enabled or disabled by using Special Function 13 This feature allows the user to disable the X Y recorder during a sweep Some delay may be noted when pressing keys during sweep with an X Y recorder enabled This delay allows the pen to lift before moving on Keys pressed during th
8. gt OE OUTPUT INPUT TCH AMS AVG VOLTMETER RIGHT DISPLAY di oie FEIER CONTROLLER AMPLITUDE GEEE INPUT AMPLIFIER RANGING DETECTOR AMPLIFIER ATTENUATOR OSCILLATOR The Controller coarse tunes the Notch Filter to the same frequency as the Oscillator SINAD Measurement Block Diagram SINAD 3 121 Model 8903B COMMENTS If an external oscillator is used it must be tuned to within 596 of the internal oscillator frequency SINAD can be measured with either the true rms or average responding detector Most applica tions specify true rms detection Using the Quasi peak Detector for SINAD measurements is not recommended During a SINAD measurement the output detector uses increased filtering to obtain more consistent readings in the presence of noise Special Function 7 can be used to change the SINAD meter range refer to Special Functions For SINAD ratios less than 25 dB the digital display is automatically rounded to the nearest 0 5 dB to reduce digit flicker The SINAD meter has hysteresis The trip point for the 24 dB range is gt 18 dB and the trip point for the 18 dB range is lt 17 dB RELATED SECTIONS Amplitude Detector Selection Frequency Special Functions 3 122 SINAD E uu Model 8903B Operation Special Functions DESCRIPTION General Information Special Functions extend user control of the instrument beyond tha
9. El Local Lockout When a data transmission is interrupted which can happen by returning the Audio Analyzer to local mode by pressing the LCL key the data could be lost This would leave the Audio Analyzer in an unknown state To prevent this a local lockout is recommended Local lockout disables the LCL key and the CLEAR key and allows return to local only under program control NOTE Return to local can also be accomplished by turning the Audio Analyzer s LINE switch to OFF then back to ON However this technique has several disadvantages e It defeats the purpose and advantages of local lockout that is the system controller will lose control of a system element e There are several HP IB conditions that reset to default states at turn on 3 29 i gt Data Messages 3 26 Model 8903B The Audio Analyzer communicates on the interface bus primarily with data messages Data messages consist of one or more bytes sent over the 8 data bus lines when the bus is in the data mode attention control line AT N false Unless it is set to Talk Only the Audio Analyzer receives data messages when addressed to listen Unless it is set to Listen Only the Audio Analyzer sends data messages or the Status Byte message if enabled when addressed to talk Virtually all instrument operations available in local mode may be performed in remote mode via data messages The only exceptions are changing the LINE sw
10. South Africa India 8120 4211 8120 4600 STR STR IEC83 B1 STR 90 250V 8120 1860 Jade Gray STR STR CEE22 V1 Systems Cabinet Use STR STR 8120 1575 Jade Gray Figure 2 2 Power Cable and Mains Plug Part Numbers 2 4 Model 8903B Installation To set the HP IB Address on the Audio Analyzer 1 Disconnect the line Mains power cable 2 Remove any HP IB cables or connectors f rom the HP IB connector 3 Remove the Audio Analyzer top cover a Remove the two plastic feet from the rear of the top cover by removing the panhead Pozidriv screw within each foot b Unscrew the Pozidriv screw at the center of the rear edge of the top cover This is a captive screw and will cause the top cover to pull away from the front frame c Lift off the top cover d Locate the HP IB address switch accessible through a hole near the center rear of the internal shield cover 4 Use a pencil to set the switches to the desired HP IB address and Talk Only TON or Listen Only LON condition The switch is illustrated in Figure 2 3 Facing the board the left hand switch marked with a 5 is the most significant address bit A5 in Table 2 1 Setting a switch toward the printed circuit board places it in its 1 position If the TON and LON switches are both set to 1 the Talk Only setting will override If the address switches and the TON switch are all set to 1 the Audi
11. 3 76 Hold Decimal Point Model 8903B Operation PROGRAM CODES x For HP IB codes refer Procedure above INDICATIONS the numeric code is entered both displays will blank and the entered code will appear in the left display When the SPCL key is pressed the SPCL key LED will light if it is not already on If it is already on it will remain on The right display will show the amplitude with the decimal held in the position requested The left display provides the normal information associated with the selected measurement mode COMMENTS It is possible to use the Hold Decimal Point Special Function to set the display for a readout that exceeds the resolution of the instrument For example in the dc level measurement mode 4 7 SPCL will set the display to a mV range In this case the three digits following the decimal point will always be zeros and are not significant digits in the amplitude readout RELATED SECTIONS Automatic Operation Special Functions Hold Decimal Point 8 77 Operation Model 8903B Hold Settings Special Function 9 DESCRIPTION The Hold Settings Special Function is used to freeze the instrument in the presently selected settings for the input level ranges the post notch gain the decimal point position and the notch tuning PROCEDURE To hold the presently selected settings for the functions above press 9 0 then the SPCL key EXAMPLE To hold the present settings of the specif
12. Cannot confirm source frequency This error indicates that in notch routine the frequency could not be measured and thus the notch could not be adjusted This usually indicates a counter problem Refer to Service Sheet 14 This error code indicates that the user has entered the same upper and lower limits to scale the sweep of the X Y plotter output This would cause a division by zero The user should enter some realistic plot limits Refer to X Y Recording and more particularly to Plot Limit Top and bottom plotter limits are identical RATIO not allowed in present mode This error code indicates that use of the RATIO key does not make sense in the current mode Refer to RATIO and LOG LIN Input overload detector tripped in range hold This error code indicates that the input signal is too high for the selected range Press CLEAR key and then enter a more realistic range setting or press AUTOMATIC OPERATION key to allow the Audio Analyzer to seek the correct input range Refer to Automatic Operation Cannot make measurement This error code indication occurs when the input signal is changing too quickly for the Audio Analyzer to make consistent measurements or when the common mode signal is too large for the Audio Analyzer The display indicates that the instrument is trying to make a measurement After nine unsuccessful tries Error 31 is displayed
13. a A A A A LL A LCA UU wit As Dei uu ME pit tT Pet TT Figure 1 3 Two Tone Burst Sequence 15 ms Duration Systems The Audio Analyzer features capabilities for general systems applications The audio source is programmable in frequency level and output impedance has very low distortion The distortion measurements are fully automatic programmable and fast The typical time to tune and return the first distortion measurement is 1 5 seconds with a measurement rate of 2 readings second thereafter The combined distortion of the internal source together with the measurement section is typically 0 003 90 dB between 20 Hz and 20 kHz at a 1 5V level Often systems applications involve measuring low level ac signals The Audio Analyzer features a full range ac level display of 0 3000 mV with an accuracy of 4 of reading 2 of reading for levels gt 50 mV and from 20 Hz to 20 kHz The ac detector is switchable between true rms average responding and Quasi peak detection The 3 dB measurement bandwidth for each detector is greater than 500 kHz Since many systems have noise problems the Audio Analyzer has both 30 and 80 kHz low pass filters to reject high frequency noise In addition the optional internal plug in 400 Hz high pass filter attenuates line related hum and noise by more than 68 dB Two special binary programming modes are available in remote operation A rapid frequency count mode provides a pa
14. 17 0SP 17 1SP 17 2SP 17 3SP 17 4SP 17 5SP 17 6SP 17 7SP 17 8SP 17 9SP Sweep Resolution Maximum 255 points sweep Display Level in Watts 19 0 19 0SP 19 NNN 19 NNNSP Model 8903B Special Function Summary 3 of 4 Description 1 2s delay 1 4s delay 1 6s delay 1 8s delay Enable plot Disable plot Minimum time be tween measurements Add 1s between measurements 0 01 dB above 25 dB 0 5 dB below 25 dB 0 01 dB all ranges 10 points decade 1 point decade 2 points decade 5 points decade 10 points decade 20 points decade 50 points decade 100 points decade 200 points decade 500 points decade Display level as watts into 8 ohms Display level as watts into NNN ohms Read right display Read left display Disable SPCL AUTO Meas CLEAR Lights lt lt lt lt lt lt lt lt lt lt i z pf ele lt lt m EE BEER un xxxxxXXAXG Read Display to 20 0SP HP IB 20 1SP No Not Applicable Y Yes Except the LCL S Shift and Numeric Keys 3 126 Special Functions 8908 Operation Special Function Summary 4 of 4 De Function HP IB Lights cz Description iin OP e Ses Address 21 0 21 0SP Displays HP IB ad dress in binary in left display right display in form TLS where T 1 means talk only L 1 means listen only S 1 means SRQ 21 1SP Displays HP I
15. Input Impedance High Input Low Input 51 00 51 00 20 COMMON MODE REJECTION RATIO PERFORMANCE TEST Function Hz 1 12 1 000 1 20 000 32 1 1 20 000 32 1 000 5 6 20 5 6 4 4 Model 8903B Adjustments Section 5 ADJUSTMENTS 5 1 INTRODUCTION This section contains adjustments and checks that assure peak performance of the Audio Analyzer The instrument should be readjusted after repair or failure to pass a performance test Allow a 30 minute warm up prior to performing the adjustments Removing the instrument top cover and the internal shield cover is the only disassembly required for all adjustments To determine which performance tests and adjustments to perform after a repair refer to paragraph 5 5 Post Repair Tests Adjustments and Checks 5 2 SAFETY CONSIDERATIONS This section contains information cautions and warnings which must be followed for your protection and to avoid damage to the equipment Adjustments described in this section are performed with power supplied to the instrument and with protective covers removed Maintenance should be performed only by service trained personnel who are aware of the hazard involved for example fire and electrical shock Where maintenance can be performed without power applied the power should be removed 5 3 EQUIPMENT REQUIRED Most adjustment procedures contain a list of required test equipment The test equipment is also identified by c
16. 40 2 kHz 10 dB 20 kHz DISTN 40 2 kHz 10 dB 20 kHz SINAD 40 2 kHz 10 dB 20 kHz SIG NOISE 40 2 kHz 80 dB 20 kHz SIG NOISE 40 2 kHz 80 dB 20 kHz SINAD 40 2 kHz 80 dB 20 kHz DISTN Readings in step 10 201 kHz 10 dB 100 kHz DISTN 201 kHz 10 dB 100 kHz SINAD 201 kHz 60 dB 100 kHz SINAD 201 kHz 60 dB 100 kHz DISTN 301 5 kHz 60 dB 100 kHz DISTN 301 5 kHz 60 dB 100 kHz SINAD 301 5 kHz 10 dB 100 kHz SINAD 301 5 kHz 10 dB 100 kHz DISTN rev 15MAYS88 79 0 dB 9 4 dB 11 4 dB 21 0 dB 31 0 dB 41 0 dB 51 0 dB 61 0 dB 71 0 dB 81 0 dB 81 0 dB 11 4 dB 11 4 dB 81 0 dB 81 0 dB 11 4 dB 11 4 dB 9 4 dB 9 4 dB 79 0 dB 79 0 dB 81 0 dB 12 4 dB 8 4 dB 58 0 dB 62 0 dB 62 0 dB 58 0 dB 8 4 dB 12 4 dB 81 0 dB 11 4 dB 9 4 dB 19 0 dB 29 0 dB 39 0 dB 49 0 dB 59 0 dB 69 0 dB 79 0 dB 79 0 dB 9 4 dB 9 4 dB 79 0 dB 79 0 dB 9 4 dB 9 4 dB 11 4 dB 11 4 dB 81 0 dB 81 0 dB 79 0 dB 4 37 Performance Tests Model 8903B Table 4 1 Performance Test Record 9 of 12 VIENNE RN Fe m FREQUENCY ACCURACY AND SENSITIVITY PERFORMANCE TEST Audio Input iioi Level Frequency ode mV Hz AC LEVEL 5 20 19 99 20 01 DISTN 50 20 19 99 20 0
17. COMMENTS The Audio Analyzer powers up with an upper and lower plot limit of 100 and 100 respectively The plot limit values can range from 1099 to 1099 in steps of 0 001 The values entered for the upper and lower plot limits are dimensionless The plot limit units are the same as the right display measurement unit For example if an upper plot limit of 20 and a lower plot limit of 10 are entered and the measurement result is displayed in dB the upper plot limit would correspond to 20 dB and the lower plot limit would correspond to 10 dB If the measurement result had been displayed in instead of dB the upper plot limit would have corresponded to 2096 while the lower plot limit would have corresponded to 10 The plot limit units can be any of the following fundamental units V dB dBm and Note that mV cannot be used as a plot limit unit If the upper and lower plot limits are identical and the SWEEP key is pressed Error 25 will be displayed If plot limits are entered whereby the lower limit is greater than the upper limit no error code is displayed In this case the Y axis output ranges from approximately 10 Vdc for the lower plot limit value to 0 Vdc for the upper plot limit value and the X Y plot obtained is simply inverted For example if an upper plot limit of 10 and a lower plot limit of 20 are entered and the measurement result is displayed in dB the upper plot limit would correspond to 10 dB and the lower
18. See Service Sheet 7 Connect the voltmeter to the HIGH INPUT of the Audio Analyzer as shown in Figure 5 4 Set the voltmeter to read ac volts On the Audio Analyzer set the MEASUREMENT mode to AC LEVEL Adjust A4R91 RMS SCALE for a reading on the right display of the Audio Analyzer that is the same as the reading on the ac voltmeter within 1 mV See Service Sheet 6 Adjustment 7 5 13 Adjustment 5 14 10 11 12 13 Model 8903B On the Audio Analyzer set AMPTD to 150 mV Adjust A4R85 RMS OFFSET for a reading on the right display of the Audio Analyzer that is the same as the ac reading on the ac voltmeter within 0 5 mV See Service Sheet 6 If A4R85 does not have sufficient range add or alter A4R143 or A4R144 as follows a Unsolder A4R143 or A4R144 if present b With a voltmeter measure the voltage at the junction of A4R72 and A4C46 c If the voltage ignoring polarity is greater than 2 mV compute R 1500 V where V is the voltage measured in volts d Select a resistor which has a standard value resistance nearest R If the measured voltage was negative solder the resistor in the location for A4R143 if positive for A4R144 e After a five minute warm up measure the voltage again which should be between 2 and 2 mVdc f Repeat the adjustment of A4R85 On the Audio Analyzer set AMPTD to 3V Repeat steps 5 through 7 until the right display of the Audio Analyzer an
19. 30 9 to 29 5 11 7 to 10 3 0 2 to 0 2 0 5 to 1 9 3 2 to 1 8 10 8 to 7 8 Distortion Check 24 20 Set all filters on the Audio Analyzer off Press LOW PASS 80 kHz Press DISTN The DISTN key light should light Set the source frequency to 1 kHz The right display should show 0 01 or less SINAD Check 26 21 Press SINAD The SINAD key light should light The right display should show 80 dB or more Key in 6 1 SPCL to hold the notch filter Set the source frequency to 890 Hz The right display should show between 12 and 19 dB The SINAD meter should read within 1 dB of the right display Signal to Noise Ratio Check 28 Press AUTOMATIC OPERATION Press S Shift SIG NOISE The right display should show 85 dB or more Sweep X Axis Y Axis Pen Lift and DC Level Check 29 30 81 32 33 34 35 36 Disconnect the cable from the OUTPUT and reconnect it to the X AXIS connector on the rear panel Press S Shift DC LEVEL Press SWEEP The right display should show a voltage rising from approximately 0 to 10V in uniform steps Move the cable from the X AXIS connector to the Y AXIS connector Press START FREQ The right display should show between 0 01 and 0 01V Press STOP FREQ The right display should show between 9 6 and 10 4V Disconnect the cable and reconnect it to the PEN LIFT connector Press SWEEP The right display should momentarily show a T TL high le
20. Check that both the Audio Analyzers REMOTE and ADDRESSED annunciators are on The controller s display should read 9009600000 00 HPL or 9009600000 BASIC Address the Audio Analyzer to talk and store the data red 728 V ENTER 728 V in variable V Check that the controller s run indicator is still on indicating that it has not received data from the Audio Analyzer Press the Audio Analyzer s CLEAR key The controller s run indicator should turn off 3 7 REMOTE OPERATION HEWLETT PACKARD INTERFACE BUS The Audio Analyzer can be operated through the Hewlett Packard Interface Bus HP IB Bus compatibility programming and data formats are described in the following paragraphs Except for the LINE switch the 10 and x10 keys the low terminal ground FLOAT switches and the Controller Reset Service Special Function all Audio Analyzer operations including service related functions are fully programmable via HP IB In addition rapid source tuning and rapid frequency count capabilities not available from the front panel are provided in remote operation A quick test of HP IB is described under HP IB Functional Checks These checks verify that the Audio Analyzer can respond to or send each of the applicable bus messages described in Table 3 3 For more information about HP IB refer to IEEE Standard 488 ANSI Standard MC1 1 the Hewlett Packard Electronic Systems and Instruments catalog and the booklet Tutorial Descript
21. Controller The entire operation of the instrument is under control of a microprocessor based Controller The Controller sets up the instrument at turn on interprets Keyboard entries executes changes in mode of operation continually monitors instrument operation sends measurement results and errors to the front panel displays and interfaces with HP IB In addition its computing capability is used to simplify circuit operation For example it forms the last stage of the Counter converts measurement results into ratios in or dB etc It also contains routines useful for servicing the instrument 1 14 BASICS OF AUDIO MEASUREMENTS The audio frequency range is usually taken to be from 20 Hz to 20 kHz Few people have hearing that good but the term is a convenient one to describe sub RF frequencies encountered in electronics The frequency range of the Audio Analyzer extends beyond the audio range to include fundamentals up to 100 kHz Electronic instrumentation provides most of the tools for quantitative analysis of audio signals Thus if the signal is non electrical for example mechanical or acoustic it must be converted to an electrical signal by a transducer of some kind for example strain gauge or microphone before it can be analyzed Apart from attentive listening to a hi fi system the most intuitive way of analyzing an electrical signal in the audio range is visually with an oscilloscope Here you get a feeling for the signa
22. N Do not apply more than 300 Vrms to the INPUT Section Page Inputs and Outputs IN Float NEM Ata Sa 3 72 MOMOR x Codex etes uta 3 90 X Y Recording 3 137 Special Functions Detector Selection 3 53 Display Level in Watts 3 55 Display Source Setting 3 57 Error Disable 3 62 Hod Decimal Point 3 76 Hold Settings iron VE ERE 3 78 HP IB Address 3 80 Input Level Range DC Level 3 86 Input Level Range Except DC Level 3 88 NOCH TUNG 2 43202 oco er Sarees 3 93 Post Notch Detector Filtering 3 100 Post Notch Gain 3 102 Read Display to HP IB 3 114 Service Request Condition 3 116 Special Functions 3 123 Sweep Resolution 3 133 Time Between Measurements 3 136 HP IB HP IB Address 3 80 Rapid Frequency Count 3 104 Service Reques Condition 3 116 Rapid SOUICB 12 grees rediere pu ex 3 107 Read Display to HP IB 3 114 Miscellaneous Automatic Operation 3 46 Default Conditions and Power up Sequence 5 vos cx edipi bee d re 3 52 qe 3 72 rev 15MAY88 Model 8903B Operation 3 4 REAR
23. The output from the Audio Analyzer s source set to 1 Vrms at 1 kHz is connected to both the high and low inputs to the Audio Analyzer The low input is set to float The ac level of the common mode rejection is then adjusted for minimum response 8903B AUDIO ANALYZER HIGH INPUT 8580 onoo gt 288 Bo ES Seca 0 Been Figure 5 2 Common Mode Rejection Adjustment Test Setup Procedure 1 On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Set the OUTPUT switch to ground Set the INPUT switch to FLOAT Key in 47 0 SPCL to set the Source impedance to 6000 Set AMPTD to 1V 2 Connect the HIGH OUTPUT to the HIGH INPUT through the tee as shown in Figure 5 2 3 Adjust A2R43 CM for the minimum level on the right display but less than 0 2 mV 4 Perform the Common Mode Rejection Ratio Performance Test Performance Test 8 5 8 Adjustment 3 Model 8908 Adjustments Adjustment 4 INPUT DC OFFSET ADJUSTMENT Reference Service Sheet 1 Description With the Audio Analyzer set to measure dc level and the input grounded the dc offset is adjusted for a display of 0V Equipment Feedthrough Termination 6000 ieu Sachs dE orbem estu ade eee eed Eb RS E Reds HP 11095A Procedure 1 Key in 41 0 SPCL to initialize the instrument Set the INPUT switch to ground Set MEASUREMENT to DC LEVEL 2 Connect the 6000 feedthrough or a short circuit or a 50 1 load to the HIGH INPU
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26. DISTORTION AND NOISE PERFORMANCE TEST 20 Hz 6 0V DISTN 80 kHz 1 kHz 6 0V DISTN 80 kHz 1 kHz 5 0V DISTN 80 kHz 1 kHz 3 8V DISTN 80 kHz 1 kHz 0 6V DISTN 80 kHz 1 kHz 0 6V SIG NOISE 80 kHz 85 dB 20 kHz 6 0V DISTN 80 kHz 50 kHz 6 0V DISTN Off 50 kHz 0 6V DISTN Off 50 kHz 0 6V SIG NOISE Off 70 dB 100 kHz 6 0V DIST Off 100 kHz 5 0V DIST Off 100 kHz 3 8V DIST Off 30 3 Vdc 3 03 Vdc 0 606 Vdc 0 066 Vdc 0 054 Vdc 0 594 Vdc 2 97 Vdc 29 7 Vdc 297 4 36 8908 Performance Tests Table 4 1 Performance Test Record 8 of 12 Test No Test Description DISTORTION SINAD AND SIGNAL TO NOISE ACCURACY PERFORMANCE TEST Readings in step 9 100 Hz 10 dB 25 Hz DISTN 100 Hz 10 dB 25 Hz SINAD 100 Hz 80 dB 25 Hz SINAD 100 Hz 80 dB 25 Hz DISTN 100 Hz 80 dB 50 Hz SIG NOISE 100 Hz 10 dB 50 Hz SIG NOISE 4 02 kHz 10 dB 2 kHz DISTN 4 02 kHz 20 dB 2 kHz DISTN 4 02 kHz 30 dB 2 kHz DISTN 4 02 kHz 40 dB 2 kHz DISTN 4 02 kHz 50 dB 2 kHz DISTN 4 02 kHz 60 dB 2 kHz DISTN 4 02 kHz 70 dB 2 kHz DISTN 4 02 kHz 80 dB 2 kHz DISTN 6 03 kHz 80 dB 2 kHz DISTN 6 03 kHz 10 dB 2 kHz DISTN 8 04 kHz 10 dB 2 kHz DISTN 8 04 kHz 80 dB 2 kHz DISTN 10 05 kHz 80 dB 2 kHz DISTN 10 05 kHz 10 dB 2 kHz DISTN
27. Fixed L Line Feed Error Code Carriage Return Fixed Exponent For example Error 10 is output to the HP IB as 90010E 05CRLF This format differs from normal data outputs since normal data outputs will never exceed 4 x 10 Once an error has been input to the computing controller the error code is simply derived by subtracting 9 x 10 from the input number then dividing the result by 100 000 ERROR DISPLAYS Shown below and on the next page are three types of error displays T he first is typical of most error displays and is shown as a general case The second and third have specific meaning and occur often This display shows the general error display format These errors are output to the HP IB as shown under the HP IB format above 3 64 Error Message Summary Model 8903B Operation This display means that no signal has been sensed at the input This display is output to the HP IB as Error 96 using the HP IB format shown above This display means that a signal has been detected but for various reasons a measurement result is not yet available This display is never output to the HP IB and typically indicates a transitory state in instrument operation After nine successive occurrences the display changes to Error 31 Error 31 is output to the HP IB using the HP IB format shown above ERROR MESSAGES The table below describes all Operating and Entry errors The error code message and the action typically
28. Float DESCRIPTION To minimize measurement errors caused by ground loops both the source output and the analyzer input can be floated Floating the input improves rejection of low frequency and common mode signals for example line related hum and noise The two front panel FLOAT switches determine whether the input and output circuitry are floating or single ended When the analyzer input is in the float mode the input is fully balanced This is not true for the source output when floated PROCEDURE To float either the analyzer input or the source output set the corresponding FLOAT switch to the FLOAT position In the float mode the LOW center conductor is isolated from chassis ground In the single ended mode the FLOAT switch in the grounded position the LOW center conductor is connected directly to chassis ground COMMENTS The INPUT and OUTPUT BNC connectors allow the attachment of shielded cables which minimize electromagnetic interference EMI This is important if the Audio Analyzer is operated near a transmitter or in the presence of large RF signals The outer conductor of each BNC connector is connected directly to chassis ground When the FLOAT switch is in the grounded position the center conductor of the LOW connector is required if BNC coaxial cable is connected the other HIGH connectors must be connected If EMI shielding is not critical banana type connectors ean be used Four BNC to banana adapters are supplied
29. Front panel CLEAR key initiates Trigger with Settling measurement Status Byte e _5_ Weit 18 __ 0 Service RQS Bit Request Require 0 always 0 always 0 always Condition always Service Notes 1 The condition indicated in bits 1 and 3 must be enabled to cause a Service Request by Special Function 22 Service Request Condition 2 The RQS bit bit 7 is set true whenever an HP IB code error occurs or when any of the conditions of bits 1 and 3 are enabled and occur 3 Bits set remain set until the Status Byte is cleared Complete HP IB Capability as described in IEEE Std 488 and ANSI Std MC1 1 SH1 AH1 T5 TEO L3 LEO SR1 RL1 PPO DC1 DT1 El For information on Rapid Frequency Count or Rapid Source modes refer to them by name in the Detailed Operating Instructions 3 36 Model 8903B um Operation Tuble 3 6 Audio Analyzer Parameter to HP IB Code Summary Internal Plug in HP BP Filters Left Plug in Filter on Right Plug in Filter on All Plug in HP BP Filters off Source Function Start Frequency Stop Frequency Plot Limit Frequency Increment LP Filters Amplitude 30 kHz LP Filter on 80 Khz LP Filter on All LP Filters off Amplitude Increment Data minus Ratio Clear On 0 9 Off decimal point Units Log Lin kHz Log V Lin Upper Limit Hz Trigger Modes mV Free Run Lower
30. HEWLETT PACKARD INTERFACE BUS Compatibility The Audio Analyzer is compatible with HP IB to the extent indicated by the following code SH1 1 T5 L3 LEO SR1 RL1 PPO DC1 DT1 CO E1 The Audio Analyzer interfaces with the bus via open collector TTL circuitry An explanation of the compatibility code can be found in IEEE Standard 488 IEEE Standard Digital Interface for Programmable Instrumentation or the identical ANSI Standard MC1 1 For more detailed information relating to programmable control of the Audio Analyzer refer to Remote Operation Hewlett Packard Interface Bus in Section 3 of this manual Selecting the HP IB Address The HP IB address switches are located within the Audio Analyzer The switches represent a five bit binary number This number represents the talk and listen address characters which an HP IB controller is capable of generating In addition two more switches allow the Audio Analyzer to be set to talk only or listen only A table in Section 2 shows all HP IB talk and listen addresses Refer to HP IB Address Selection in Section 2 of this manual 1 9 ACCESSORIES SUPPLIED The accessories supplied with the Audio Analyzer are shown in Figure 1 4 Fast blow fuses with a 1 5A rating for 100 120 Vac operation HP 2110 0043 and a 1 0A rating for 220 240 Vac operation HP 2110 0001 are supplied One fuse is installed in the instrument at the time of shipment The rating of the installed fuse is selected
31. Having a serial number prefix that is greater than that shown on the title page indicates that the instrument 1s slightly different from those documented in the manual In this case your manual is provided with updating information to make it as current as possible This updating information includes any hardware or software changes that have occurred as well as corrections to the manual A Description of the Manual Update Packet A MANUAL UPDATES packet is shipped with the Operation and Calibration Manual when necessary to provide you with the most current information available at the time of shipment These packets consist of replacement and addition pages which should be incorporated into the manual to bring it up to date Signing Up for the Documentation Update Service Hewlett Packard offers a Documentation Update Service that will provide you with further updates and changes as they become available If you have not received update information that matches the serial number of your instrument you can receive this information through the Update Service If you operate or service instruments with different serial prefixes we strongly recommend that you join this service immediately to ensure that your manual is kept current For more information refer to the Documentation Update Service reply card included in this manual or contact Hewlett Packard Company Technical Writing Department 24001 E Mission TAF C 34 Spokane WA 99220
32. NEAR TERMINATION P O TWISTED PAIR WITH 8 NDAC OF OTHER WIRE OF P O TWISTED PAIR WITH 7 NRFD TWISTED PAIR P O TWISTED PAIR WITH 6 DAV REN EOI DIO 8 DIO 4 DIO 7 DIO 3 DIO 6 DIO 2 DIO 5 DIO 1 ISOMETRIC THREAD M3 5 x 0 6 24 PIN MICRO RIBBON SERIES 57 CONNECTOR Logic Levels The Hewlett Packard Interface Bus logic levels are TTL compatible that is the true 1 state is 0 0 Vdc to 0 4 Vdc and the faise 0 state is 2 5 Vdc to 5 Vdc Programming and Output Data Format Refer to Section 3 Operation Mating Connector HP 1251 0293 Ampheno 57 30240 Mating Cables Available HP 10631A 1 meter 3 3 ft HP 10631B 2 meters 6 6 ft HP 10631C 4 meters 13 2 ft HP 10631D 0 5 meters 1 6 ft Cabling Restrictions 1 A Hewlett Packard Interface Bus system may contain no more than 2 meters 6 6 ft of connecting cable per instrument 2 The maximum accumulative length of connecting cable for any Hewlett Packard Interface Bus system is 20 meters 65 6 ft Figure 2 4 Hewlett Packard Interface Bus Connection x 2 9 8908 Operation Section 3 OPERATION 3 1 INTRODUCTION General This section provides complete operating information for the Audio Analyzer Included in this section are descriptions of all front and rear panel controls connectors and indicators remote and local operator s checks operating instructions and operator s maintenance Operating Characteristics Table 3 1 briefly summ
33. Special Function Performance Test 1 Model 8903B Performance Tests AC Calibrator Ratio Limits 9 Special Level Frequency e Maximum 10 100 000 96 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 Performance Test 1 4 7 Performance Tests Model 8903B AC Calibrator Ratio Limits Frequency Hz 0 15 20 98 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 Special Function Low Level Low Input AC Level Accuracy 5 Replace the ac calibrator with the audio synthesizer Leave the HIGH INPUT shorted to ground Set the audio synthesizer s level to approximately 7 mV rms as read on the Audio Analyzer 6 Set the audio synthesizer to the frequency indicated in the table below For each setting perform the following procedure a Press RATIO if it is on Set the audio synthesizer to 7 mV rms as read on the Audio Analyzer Press RATIO b Decrease the level of the audio synthesizer by exactly 26 dB Note the reading of the right display of the Audio Analyzer c Multiply
34. Special Function 22 has no effect on the SPCL key light When any enabled condition occurs both the RQS bit and the bit corresponding to the enabled condition are set in the status byte and the SRQ control line on the HP TB will be set true The Audio Analyzer s status byte is shown below for reference Audio Analyzer s Status Byte Instru m Mm ment COMMENTS Error For more information on HP IB operation serial polling and the Status Byte message refer to the HP IB discussion titled HP IB Operation appearing earlier in Section 3 of this manual The HP IB Address Special Function provides a convenient means to determine at any time whether a Require Service message is being issued by the Audio Analyzer RELATED SECTIONS HP IB Address HP IB Operation appears earlier in Section 3 Service Request Condition 3 117 Model 8903B Signal to Noise DESCRIPTION The instrument uses its internal source to make signal to noise measurements The source is set to a specified value and alternately turned on and off The measurement is made by first determining the following value _ signal noise D D is then converted into the appropriate measurement units as follows units D X 100 dB units 20log D The RATIO key can be used to compare these values to a predetermined ratio reference refer to RATIO and LOG LIN The signal to noise measurement can be made on source signals from 5
35. UE 5 is the HP IB code for DC LEVEL INDICATIONS When dc level is selected the LEDs within the DC LEVEL key and the S Shift key will light The right display shows the dc level with the appropriate units The Audio Analyzer automatically ranges for maximum resolution and accuracy In the dc level measurement mode the left display is blanked even though an ac signal may be present MEASUREMENT TECHNIQUE In the dc level measurement mode the Audio Analyzer automatically sets the input attenuation and the gain of the input amplifier so that the signal amplitude lies within the proper range of the dc voltmeter The signal is then measured by the dc voltmeter and after correction for input gain and attenuation displayed in appropriate units zn MET RIGHT OISPLAY ATTENUATOR AMPLITUDE AMPLIFIER DC Level Measurement Block Diagram 3 50 DC Level Model 8903B Operation COMMENTS CAUTION THE INPUT SIGNAL IS NOT TO EXCEED 300V WITH RESPECT TO GROUND OR DIFFERENTIAL Some input signal limitations apply to the size of the common mode signals See the Common Mode detailed operating instruction for details In the dc level measurement mode only the ac component of the input signal is coupled to the MONITOR output The ac component also affects the input gain RELATED SECTIONS Common Mode RATIO and LOG LIN Special Functions DC Level 3 51 Operation Model 8903B Default Conditions and Power up Sequence DESCRIP
36. panels meters Inspect the shipping container for damage If the shipping container or cushioning material is damaged it should be kept until the contents of the shipment have been checked for completeness and the instrument has been checked mechanically and electrically Procedures for checking electrical performance are given in Section 4 If the contents are incomplete if there is mechanical damage or defect or if the instrument does not pass the electrical performance test notify the nearest Hewlett Packard office If the shipping container is damaged or the cushioning material shows signs of stress notify the carrier as well as the Hewlett Packard office Keep the shipping materials for the carrier s inspection 2 3 PREPARATION FOR USE Power Requirements To avoid the possibility of hazardous electrical shock do not operate this instrument at line voltages greater than 126 5 Vac with line frequencies greater than 66 Hz Leakage currents at these line settings may exceed 3 5 The Audio Analyzer requires a power source of 100 120 220 or 240 Vac 5 10 48 to 66 Hz single phase or 100 or 120 Vac 5 to 10 48 to 440 Hz single phase Power consumption is 100 VA maximum 2 1 Installation Model 8903B This is a Safety Class I product that is provided with a protective earth terminal An uninterruptible safety earth ground must be provided from the mains power source to the product input wiring termi
37. tiG y oa Sed pL OC E WCG Rd ede dod rra 3 74 Hold Decimal Point Emu RAO rir Ra ds 3 76 Hold Settings 2 ice ao odo od ise wreck Se SUS ee 3 78 GC oc i Sr orice tae ae Be te et ee Ge Oe ee ees re ee 3 79 ode bess Sha ow es Ee A ee OS ae ore et 3 82 Input Level Range DC Level ise d we ae AS eC ee boe Set dc ec de Codi Fe ee S 3 84 Input Level Range Except DC Level 3 86 COE vere ees bee ob es Ss A de SS Ge ee 3 88 Notch Gok es ee ein E Se me ae Ak Se a a 3 91 Output Impedance 3 s dg doe en ee ee SS a ee dit ge eA ees d 3 93 Piot Lm kesh eas See pte a ac Beta a eee aa 3 96 Post Notch Detector Filtering Except SINAD leeren 3 98 Table of Contents HP 8903B P st Noteh 442599 4 9 Roco SOR d OCC dc RU OR UR ee tolo SE ee HOUR BUS USt ee 3 100 Rapid Frequency Count hr Gk Sk be ONDE de A a I OR BOE cie Ros rte d 3 102 Rapid SOUTCE sioe gore eve Deep dex es Bh Wg etae edu 3 105 RATIO and LOG LIN Gk ee e ok del Ew op i wem EE un dixe EOS P he wa 3 109 Read Display to HP IB uui o Xo SEE IE E No ade OP ISDN EU cs 3 112 Servic
38. 0 0 3 12 Fiter Cheek 08 2 508 Gare re a OR Oe EE OE ee a 2 8 3 18 Distortion Checka vac a Se CX suse awe eb OE nt d Oe Pea we 3 15 SINAD Check 2 eon Em Lowe ch omg a RS TO ESE A Se ee 3 15 Signal to Noise Ratio Check ee 3 15 Sweep X Axis Y Axis Pen Lift and DC Level Check e nnm 3 15 HP IB Runetional Checks seau gasra a m AO ow Pon ee Dedi dod OE ee dt ens 3 16 DescHptioBa x3 bed dp estar AUS os Bebe pode OR P a apap rege ar 3 16 Initial Setup x 65 468 wen wd tee Aw dom pud te cd age ad HAUS eS ee qi deve 3 16 Bguipment 2 4 6 4 EESTI LO Ged a ih ee ws Be a Sr ee DELLI 3 16 Address Recognition ooo e ee tnr 3 16 Remote and Local Messages and the LCL Key eee 3 17 Sending the Data Message hh rem 3 17 Receiving the Data Message tmr rr 3 18 Local Lockout and Clear Lockout Set Local Messages lees 3 18 HP 8903B Table of Contents GS Sk eae oF a Se 8 18 Abort Message ex bo XO e dum s TIU DITE 3 19 Status Byte Messages x uc ove CS C E REOR qub d p uS o dici IP BEE cR T 3 20 Require Service Message 3 21 Trigger Message and Clear Key
39. 0 5 dB to reduce digit flicker Signal to noise ratio measurements are also filtered for improved repeatability and speed 1 read ing second typical and automatic display rounding is provided For accurate noise measurements the Audio Analyzer uses true rms detection for both SINAD and signal to noise measurements Most older instruments employ average detection which reads low for noise The discrepancy can be 1 5 dB or greater and varies with the ratio being measured For correlating results with past test data the Audio Analyzer s detector can be switched via special functions to an average responding configuration For those applications where quasi peak detection is required the analyzer Serial Prefix 2730A and above can be switched to this type of detection through special functions This detector is designed to meet the requirements specified by CCIR 468 3 For transceivers the Audio Analyzer has an optional internal plug in seven pole 400 Hz high pass filter for rejecting squelch tones Rejection of squelch tones up to 250 Hz is greater than 40 dB Therefore audio distortion measurements to 196 residual distortion can be made without disabling the transmitter squelch tones Under remote control the Audio Analyzer can generate or count burst tone sequences Typically the maximum count rate is 8 ms reading and the minimum tone duration is 12 ms This is fast enough for applications such as unsquelching pagers see Figure 1 3
40. 509 922 4001 8908 General Information 1 6 DESCRIPTION General The HP Model 8903B Audio Analyzer is a complete audio measurement system covering the frequency range of 20 Hz to 100 kHz It combines a low distortion signal source with a signal analyzer The source has a maximum open circuit output of 6 Vrms and a selectable output impedance of either 50 or 600 The analyzer can perform distortion analysis frequency count and ac level dc level SINAD and signal to noise ratio measurements The Audio Analyzer reduces the number of instruments required in many applications involving audio signal characterization The Audio Analyzer is easy to use All measurements are selected by one or two keystrokes For distortion measurements the Audio Analyzer automatically tunes to and levels the input signal Measurement and output ranges are automatically selected for maximum resolution and accuracy Furthermore tuning is independent of the source Thus the source can be set to one frequency while the analyzer is measuring the distortion on a signal at another frequency that is there is no need to tune the analyzer to the source The combined capabilities of the instrument are enhanced by microprocessor control resulting in more capability than would be available from separate instruments For example when making signal to noise ratio measurements the Audio Analyzer monitors the ac level while turning the source on and off T
41. 75 in 425 mm 16 8 in 462 mm 18 2 in Conducted and radiated interface is within the requirements of methods CE03 and REO2 of MIL STD 461B and FTZ 526 527 Conducted and radiated susceptibility meets the requirements of methods CS01 CS02 and 503 1 volt meter of MIL STD 461B dated 1980 Net Shipping Note For ordering cabinet accessories the module sizes are 5 14H x 1MW x 170 General Information Model 8903B Table 1 2 Supplemental Information All parameters describe performance in automatic operation or with properly set manual controls Typical Source to Analyzer Isolation Option 001 only System distortion and noise can be degraded when driving low impedance loads with source output impedance in the 500 mode due to coupling from the source output to the analyzer input See Figure 1 7 for the plot of various load impedances vs frequency Frequency Switching Speed 3 ms does not include HP IB programming time Sweep Mode Logarithmic sweep with up to 500 points decade or 255 points total between entered start stop frequencies Output Level Switching Speed 20 ms does not include HP IB programming time MEASUREMENT SINAD Detection True rms or rms calibrated average Resolution 0 01 dB for ratios gt 25 dB For ratios 25 dB the display is rounded to the nearest half dB to re duce digit flickering with noisy signals Full resolution is available by defeating this feature usin
42. 8903B Tuble 1 1 Specifications 2 of 5 SYSTEM SPECIFICATIONS Cont d DISTORTION Fundamental Frequency Range Display Range 20 Hz to 100 kHz 0 001 to 100 99 99 to 0 dB Accuracy 1 dB 20 Hz to 20 kHz unfiltered or with low pass filters 2 dB 20 kHz to 100 kHz Input Voltage Range 50 mV to 300V Residual Noise and 80 dB or 15 uV 20 Hz to 20 kHz 80 kHz BW Distortion the 70 dB or 45 uV 20 kHz to 50 kHz 500 kHz BW higher of 65 dB or 45 uV 50 kHz to 100 kHz 500 kHz BW AC LEVEL Full Range Display 300 0V 30 00V 3 000V 3000V 30 00 mV 3 000 mV 3000 mV Overrange 3396 Except on the 300 0V range Accuracy 2 50 mV to 300V 20 Hz to 20 kHz 4 50 mV to 300V 20 kHz to 100 kHz 4 0 3 mV to 50mV 20 Hz to 100 kHz DC LEVEL Full Range Display 300 0V 48 00V 16 00V 4 00V Overrange 33 Except on the 300 0V range Accuracy 1 0 of reading 600 mV to 300V 6 mV Vin lt 600 mV FREQUENCY Measurement Range in ac level mode In distortion SINAD and signal to noise modes 20 Hz to 150 kHz 20 Hz to 100 kHz Resolution 5 digits Frequencies gt 100 Hz 0 01 Hz Frequencies lt 100 Hz Accuracy 0 004 1 digit Sensitivity 50 mV Distortion and SINAD modes only 5 0 mV In ac level and signal to noise modes only STANDARD AUDIO FILTERS 30
43. After amplifying and low pass filtering the output from the Notch Filter is converted to dc by the Output RMS Average Quasi peak Detector and measured by the dc voltmeter When measuring distortion or distortion level the Notch Filter is automatically tuned to the frequency counted at the input to the filter Coarse tuning is via the Controller Fine tuning and balance are via circuitry internal to the Notch Filter When measuring SINAD the Notch Filter is coarse tuned by the Controller to the same frequency as the internal source Thus a SINAD measurement is normally only made with the internal source as the stimulus and permits measurements in the presence of large amounts of noise where the Controller would be unable to determine the input frequency If an external source is used in the SINAD measurement mode the source frequency must be within 5 of the frequency of the internal source The two Programmable Gain Amplifiers following the Notch Filter amplify the low level noise and distortion signals from the Notch Filter T he overall gain of the two amplifiers is normally set to maintain a signal level of 0 3 to 3V at the MONITOR output The 30 kHz and 80 kHz LP Filters are selected from the Keyboard With no low pass filtering the 3 dB bandwidth of the measurement system is approximately 750 kHz The filters are most often used to remove the high frequency noise components in low frequency SINAD and distortion measurements The output from
44. Date Test Description AC LEVEL ACCURACY AND OUTPUT LEVEL ACCURACY AND FLATNESS PERFORMANCE TEST High Level High Input AC Level Accuracy AC Calibrator Special Level Frequency Function Vrms Hz 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 4 30 Model 8903B Performance Tests Table 4 1 Performance Test Record 2 of 12 Resuts S ii umen T ab T aiam 7 AC LEVEL ACCURACY AND OUTPUT LEVEL ACCURACY AND FLATNESS PERFORMANCE TEST High Level High Input AC Level Accuracy Vrms Hz 20 1 000 20 000 50 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 50 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 Special Function 4 31 Performance Tests Model 8903B Table 4 1 Performance Test Record 3 of 12 Fg Oo Rests eee as T emm eo 7 AC LEVEL ACCURACY AND OUTPUT LEVEL ACCURACY AND FLATNESS PERFORMANCE TEST High Level High Input AC Level Accuracy AC Calibrator Spena Level Function Vrms 1 bs 20 000 100 000 100 000 20 000
45. FREQUENCY FREQUENCY INTERNAL MONITOR PLUG IN OUTPUT HONTE j HP 8P RMS AVG FI E NOTCH QUASI PEAK irt GE FILTER LP DETECTOR VOLTMETER RIGHT DISPLAY FILTER CONTROLLER AMPLITUDE m L AMPLIFIER ELE US AMPLIFIER ATTENUATOR OSCILLATOR The Controller alternately turns the Osciliator on and off for each movement Signal To Noise Measurement Block Diagram COMMENTS The Audio Analyzer s internal source must be used as the signal stimulus when making signal to noise measurements RELATED SECTIONS Amplitude Frequency RATIO and LOG LIN Signal to Noise 3 119 Model 8903B SINAD DESCRIPTION The Audio Analyzer measures SINAD Signal to Noise And Distortion by first determining the following value S signal noise and distortion and distortion S is then converted into the appropriate measurement units as follows units S X 100 dB units 20log S SINAD measurement can be made on signals from 20 Hz to 100 kHz and from 50 mV to 300V SINAD measurements are generally made to determine the sensitivity of a receiver The Audio Analyzer internal notch filter is automatically coarse tuned to the frequency of the internal oscillator to permit measurements in the presence of large amounts of impurities and to assure that the fundamental frequency is tuned out The notch filter then fine tunes itself to the signal at the instrument s input If an external os
46. Limit Hold dB Trigger Immediate dBm into 6000 dBre 775V Trigger with Settling Miscellaneous Read Left Display Read Right Display Rapid Frequency Count Rapid Source Sweep on Sweep off 1 step up step down Automatic Operation SPCL SPCL SPCL Measurements AC Levei SINAD Distortion DC Level Signal to Noise Distortion Level RMS Detector AVG Detector Automatic Notch Tuning Notch Hold Not to be confused with Clear message which is defined in Table 3 3 3 37 Operation Model 8903B Table 3 7 Audio Analyzer HP IB Code to Parameter Summary RMS Detector AVG Detector Amplitude Increment Amplitude Automatic Operation Automatic Notch Tuning Notch Hold Rapid Frequency Count Clear Read Left Display Read Right Display dBm into 6000 dBre 775V Rapid Source dB Ratio On Ratio Off SPCL stepdown Start Frequency Stop Frequency SPCL SPCL Frequency Increment DCLevel Frequency Signal to Noise Distortion Level Hz All Internal Plug in HP BP Filters off Left Plug in Filter on Right Plug in Filter on Free Run Hold Trigger immediate Trigger with Setting kHz T step up Upper Limit Log Linear Lower Limit All LP Filters off 30 kHz LP Filter on 80 kHz LP Filter on mV AC Level SINAD Distortion V Sweep off Sweep on minus 0 9 decim
47. Rapid Source 3 106 Rapid Frequency Count Ln ee ne e ses le Model 8903B Operation Rapid Source DESCRIPTION Rapid Source mode allows a remote controller to partially bypass the Audio Analyzer s internal controller and tune the source portion of the instrument directly The main advantage of this function is that by directly controlling the source the Audio Analyzer s count and tune routine is bypassed and the need to convert decimal frequency information to the binary control data is eliminated Typically in this mode the source can be programmed in less than three milliseconds This makes generation of tone burst sequences practical PROCEDURE To use the Rapid Source mode two procedures must be performed First the packed binary tuning data must be obtained from the Audio Analyzer Second the instrument is placed into the Rapid Source mode and the five byte binary tuning data is sent NOTE When using the 55 56 and 57 Special Functions entering 55 SPCL 56 SPCL and 57 SPCL will give a readback of the present instrument settings Entering 55 0 SPCL 56 0 SPCL and 57 0 SPCL will actually set the instrument settings to 0 This is a different default condition than is used with most Special Functions Normally omitting the 0 following the decimal has the same result as entering it However in the case of 55 56 and 57 Special Functions two different functions are performed For additional information refer to the
48. Rejection Ratio 4 29 Section 5 Adjustments lanes ee SO eve a es Ee ee ew ewe Eh ee Se Ge Gl 5 1 Safety Considerations 5 1 Raquipment ReGuired ar Ss Se ek ee Se ees a a LAGE Bee wk 5 1 Bactory elected Components 2 4 2 Dy cd ie 5 1 Post Repair Tests Adjustments and 5 2 Helated s UR ir ec AE we is Se UR dieti ee d 5 2 Adjustment 1 Internal Reference Frequency 5 4 Adjustment 2 Input Flathess 5 5 Adjustment 3 Common Mode Rejection 5 8 Adjustment 4 Input DC Offset 5 9 Adjustment 5 400 Hz High Pass and Weighting Bandpass Filters 5 10 Adjustment 6 Notch Filter Tune and Balance 5 12 Adjustment 7 Voltmeter o sce ardt os dc Bee dee p d db ak 5 13 Adjiustment 8 SINAD Meters 2205 es Be voe A TEC x d ae o woods eere Ye ae Be 5 15 Adjustment 9 Oscillator and Output Attenuator 5 16 Model 8903B General Information Section 1 GENERAL INFORMATION 1 1 INTRODUCTION This manua
49. SINAD is pressed the LED in the SINAD key lights and the appropriate SINAD information for the input signal is displayed MEASUREMENT TECHNIQUES In the SINAD measurement mode the controller automatically sets the input attenuation and the gain of various amplifiers This is accomplished by measuring the signal with the ranging detector This control ensures that the signal amplitude is within the proper range of the input and output detectors In addition the controller coarse tunes the notch filter to the programmed frequency of the oscillator to ensure that the Audio Analyzer will not be mistuned The oscillator is normally used as the source of the test signal If an external signal source is used it must be tuned within 5 of the oscillator s programmed frequency The input detector converts the combined signal noise distortion ac signal to dc The notch filter then removes the fundamental signal and the output detector converts the noise distortion ac signal to dc The dc voltmeter measures both signals The controller then corrects for the programmed gain and attenuation computes the ratio and displays the results in the appropriate units The frequency of the input signal is also measured and displayed a convenience the SINAD meter displays the SINAD measurement results if within its range The meter is specially marked for and sensitivity and selectivity COUNTER LEFT DISPLAY YE FREQUENCY bom MONITOR
50. SRQ DUE TO DATA READY PROCESS OTHER ROUTINES UNTIL SRQ CAUSES INTERRUPT RETURN Figure 3 4 Example Flow Chart for Driving the Audio Analyzer Using the Require Service Message SRQ 3 7 HP IB SYNTAX AND CHARACTERISTICS SUMMARY Address Set in binary by internal switches may be displayed on front panel using Special Function 21 HP IB Address Factory set to 28 decimal 11100 binary General Operating Syntax Excluding Rapid Frequency Count and Rapid Source modes Automatic Operation Source Frequency Source Amplitude Measurement Filters Special Functions Log Lin Ratio Start Frequency Stop Frequency Plot Limit Sweep Trigger Numeric Data Input Format Except in Rapid Source mode DDDDDE INN 5 Digit Signed Mantissa Exponent Magnitude leading decimal not allowed Exponent Sign Indicates Exponent Follows For information on Rapid Frequency Count or Rapid Source modes refer to them by name in the Detailed Operating Instructions 3 35 Model 8903B Operation m Output Formats Except in Rapid Frequency Count mode Data valid data output value always 9 x 10 and in fundamental units DDDDDESNNCRLFE Signed gend Lowe Line Feed Carriage Return Indicates Exponent Follows Exponent Sign Exponent Magnitude Errors 900DDE 05CRLF Error Code Line Feed Carriage Return Return to Local Front panel LCL key if not locked out Manual Trigger
51. Service Special Functions in Section 8 Acquiring the Tuning Data Three values must be acquired from the Audio Analyzer coarse tune data fine tune data and range data To do this first tune the Audio Analyzer to the desired frequency either manually or via the HP IB Then use the 55 56 and 57 Special Functions to determine the range coarse tune and fine tune values respectively Then build the five byte sequence as follows BYTE 1 BYTE 2 BYTE 3 BYTE 4 BYTE 5 T 1 BBBB T 1 T 1 BBBB T 1 T Hi binary binary binary binary binary Course tune least Fine tune least Range significant digit significant digit digit bipary Coarse tune most binary Fine tune most piney significant digit significant digit binary binary As shown above the upper four bits of each byte sent to the Audio Analyzer are always 0011 This places the resulting codes in the ASCII range of 0 decimal 48 to decimal 63 To build the five byte sequence convert the decimal data obtained via the Special Functions into binary In the case of the coarse and fine tune data split the eight bits into two groups of four representing the most and least significant digits Insert each four bit packet into its respective byte Rapid Source 3 107 Model 8903B NOTE The binary data obtained to tune the Audio Analyzer to a particular frequency may vary both with warm up and between instruments Therefore when maxim
52. Son dE Ae mun eth le AUS ak aed ed a doe Bee Bok ee oe oe 1 15 Sipbal to Noise 1 15 Internal Sour en usn Se Bie rtv Bal a ee YE he RUE SER ecd 1 16 dern AM eee ee ech me AE ees Se oe Sn a as 1 16 Table of Contents HP 8903B Section 2 installation IHtrocuction oe ER EAE we PHS EASES EERE oe 2 1 Initial Inspection o ad Ra OE ee do diede See ESE Kee eee de oat 2 1 Preparation for Use 45 5 ox a AG Sas oe Gord See a ee ee Soe oe 2 1 Power Requirements 4 5 29 64S AAW BEDS BAS we BOG Oe diode 2 1 Line Voltage and Fuse Selection 0 ce ee ee ee ee 2 2 Power Cables Sa ee domu pedo SAGES BSNL icd wot dup de EMS KEE ASS 2 2 HP IB Address S lection 223 1 dme ox XD RV ao WAS d eU eed 2 8 Interconnections v eane a oec hd de Reed de aot Su Od de SUN RC COR eo oca dics rus cites 2 5 Mating Connectors eae hades SUE DEC ae Ee Ye diet qoia Cee 2 5 Operating Environment 2333 ve x XE eR A x we Re ee ah AS UTC ie decide ene amp he ee 2 6 Bench Operation c e sour Eod o UR A don abe get Wek e Se 2 6 Rack Mounting dus eb oc E por Soe Scd apt dios See 2 6 Storage and Shipment eee eee hh heh ehm hmm nn 2 8 Environment e 2 osse eee
53. The left most point on the X axis corresponds to the start frequency NOTE No readjustment of the X Y recorder is required if the X and Y scale factors are changed The Audio Analyzer automatically scales both the X and Y axis outputs to fit in the established plot dimension 5 To execute the plot press the SWEEP key The number of frequency points plotted is determined by the sweep size the ratio of the entered start and stop frequencies and the sweep resolution selected The sweep resolution can be selected from 1 to 500 points per decade using Special Function 17 The maximum number of points allowable in one sweep is 255 EXAMPLE The following example describes how to plot the frequency response gain vs frequency of a RIAA Record Industry Association of America phonograph preamplifier The Theoretical RIAA Response Curvefigure on the last page of this section is a plot of a theoretical RIAA curve By plotting the frequency response of the phonograph amplifier on a copy of this figure the response of the phonograph amplifier can be directly compared with the theoretical response table of RIAA response values 15 also included This standard is normally specified over a range 50 Hz to 15 kHz RIAA Standard Response Frequency Hz Relative Gain dB Frequency Hz Relative Gain dB Reference frequency 3 138 X Y Recording Model 8903B Operation 1 Connect the equipment as shown in the X Y Recording Set up figure at
54. When the SPCL key is pressed the SPCL key LED will light if it is not already on If it is already on it will remain on The displays then show the source s currently programmed frequency in the left display and its currently programmed amplitude in the right display COMMENTS It is important to realize that neither display is a measurement of the source output Therefore the actual values at the OUTPUT connector may differ from the programmed values In the case of frequency there is usually only a very slight difference In the case of amplitude the difference is dependent upon the load impedance For example if the output impedance is set for 6000 a load impedance of 6000 causes the amplitude at the OUTPUT connector to be half of the programmed value RELATED SECTIONS Amplitude Automatic Operation Frequency Special Functions Display Source Settings 3 57 Operation Model 8903B Distortion DESCRIPTION The Audio Analyzer measures distortion by first determining the following value D norse distortion signal noise distortion It then converts D into the appropriate measurement units as follows units D X 100 db units 20log D The RATIO key can be used to compare the measured results to a predetermined ratio reference value refer to RATIO and LOG LIN distortion measurement can be made on signals from 20 Hz to 100 kHz and from 50 mV to 300V PROCEDURE To make a distortion measurement press
55. according to the line voltage specified by the customer If the voltage is not specified the rating of the installed fuse will be selected according to the country of destination Four type BNC to banana plug adapters HP 1250 2164 are also supplied for use when double ended inputs or outputs are desired The conductor of the banana connector is connected to the center conductor of the BNC connector adapted to These adapters are used when the front panel INPUT or OUTPUT FLOAT switches are set to FLOAT 1 10 ELECTRICAL EQUIPMENT AVAILABLE Also refer to Service Accessories Table 1 4 HP IB Controllers The Audio Analyzer has an HP IB interface and can be used with any HP IB compatible computing controller or computer for automatic systems applications Front to Rear Panel Connectors Retrofit Kit This kit contains all the necessary components and full instructions for converting instruments with front panel connections for INPUT and OUTPUT HIGH and LOW to rear panel connections For serial prefixes 2730A and below order HP part number 08903 60171 For serial prefix 2742A and above order HP part number 08903 60199 After installation and calibration performance will be identical to the HP 8903B Option 001 Rear to Front Panel Connectors Retrofit Kit This kit contains all the necessary components and full instructions for converting instruments with rear panel connections for INPUT and OUTPUT HIGH and LOW to front panel connections
56. be sent when they occur All three conditions are described below e Data Ready When the Audio Analyzer is ready to send any information except error codes or the Status Byte e HP IB Code Error When the Audio Analyzer receives an invalid Data message This condition always causes a Require Service message to be sent NOTE The display indicates a transient condition After nine attempts to make a measurement it is replaced by Error 31 which causes the Require Service message to be sent e Instrument Error When any Error is being displayed by the Audio Analyzer including the HP IB Code error Error 24 3 33 um Model 8903B Selecting the Service Request Condition Use Special Function 22 Service Request Condition to enable the Audio Analyzer to issue the Require Service message on any of the above conditions except HP IB code errors which always cause the Require Service message to be sent The Service Request Condition Special Function is entered from either the front panel or via the HP IB The conditions enabled by Special Function 22 are always disabled by the Clear message A description of the Service Request Condition Special Function and the procedure for enabling the various conditions are given under Service Request Condition in the Detailed Operation Instructions Normally device subroutines for the Audio Analyzer can be implemented simply by triggering measurements then reading the
57. earth ground terminal The WARNING sign denotes a hazard It calls attention to a procedure practice or the like which if not correctly performed or adhered to could result in personal in jury Do not proceed beyond a WARNING sign until the indicated conditions are fully understood and met The CAUTION sign denotes a haz ard It calls attention to an operating procedure practice or the like which if not correctly performed or adhered to could result in dam age to or destruction of part or all of the product Do not proceed beyond a CAUTION sign until the indi cated conditions are fully understood and met Any interruption of the protective ground ing conductor inside or outside the instru ment or disconnecting the protective earth terminal will cause a potential shock hazard that could result in personal injury Ground ing one conductor of a two conductor outlet is not sufficient protection Whenever it is likely that the protection has been impaired the instrument must be made inoperative and be secured against any unin tended operation If this instrument is to be energized via an autotransformer for voltage reduction make sure the common terminal is connected to the earth terminal of the power source Servicing instructions are for use by service trained personnel only To avoid dangerous electric shock do not perform any servicing unless qualified to do so Adjustments described in the manua
58. ed de get doo w woe Wed fen ee Been 2 8 PC cu 4426 644 we eet ahs ew Raw a ee OE EES Pee eee eras 2 8 se SEE EE DEMS See 3 1 Generals 4x weno x a he ed qoe qe Rest HORS d d A EL a gU OR ONU dp 3 1 Operating Characteristics wo m 999 y Roh es 3 1 Turn On Procedure 25a Rn ORAS ERE OLOR SES ESOS d 3 1 Local Operation 4 3 236399 alert served odes dug Bopp qoos AH eie deu ato qr d 3 2 Remote Operation 303b 9 veo e a RAE Rd Med ee Je s RU e aca e e e T 3 8 Operators Checks i 530b ee SE d we aiio edidere dra 3 3 Operators Maintenance 4 ee eee mh rnt n 3 4 Front Panel Features CC See aE RE SOE EMA A UR CORE E OON 3 6 Basic Functional Checks 2 acucac dou esd ed ws es Ge ee MG MS IER eL GR Porc AG eg 3 12 Simplified Operation 2 ee see eh hh hh hh ohh rho ht son en 3 8 R ear Panel Features ec ou od EE So oum go Oo Me eode d GEESE esed SS LS dd 3 11 Deseription i lt 6 lt 4 Sak LLL ILLA 3 12 EGUIDIeHL cu dosi dE PEASE ew CEA ds ees Eee de dove 7 3 12 Procedures e sa aeaa aa a a A T 3 12 Preliminary Check 2 2c bee ee 5 4538 tno 3 12 AC Level and Output Level Check
59. filter s key will light 3 68 Filters 1 __ _ _ _ _ Model 8903B Operation COMMENTS Two plug in positions within the instrument permit the Audio Analyzer to be configured with various high pass and band pass filter combinations The optional plug in filter assemblies include a 400 Hz High Pass used to filter out 50 60 Hz hum and squelch signals and CCITT CCIR CCIR ARM A Weighting and C Message Weighting Bandpass Filters These weighting bandpass filters are all psophometric in nature each filter characteristic approximates the response of human hearing according to separately established standards These optional plug in filter assemblies may be inserted in either the left most or right most key position according to the filter option number Left Most Key Right Most Key Position Filter Position Filter Option Number Option Number 400 Hz high pass CCITT weighting bandpass filter CCIR weighting bandpass filter C Message weighting bandpass filter CCIR ARM weighting bandpass filter A weighting bandpass filter The selected filters are always in the path of the audio signal With all filters off the 3 dB measurement bandwidth is approximately 10 Hz to 750 kHz The high pass or bandpass filters affect the signal being counted however the low pass filters do not Repeating the HP IB command to tu
60. in 41 0 SPCL to initialize the instrument Set the INPUT switch to ground Press S Shift DC LEVEL 2 Connect the output of the dc standard to the HIGH INPUT of the Audio Analyzer 3 Set the dc standard to give the output voltage indicated below For each setting the right display on the Audio Analyzer should read within the limits indicated DC Standard DC Voltage Limits Vdc Voltage Vdc 4 12 Performance Test 2 Model 8903B Performance Tests Low Input DC Level Accuracy 4 Set the INPUT switch to FLOAT Connect the output of the dc standard to the LOW INPUT of the Audio Analyzer Short the HIGH INPUT to ground 5 Set the dc standard to give the output voltage indicated below For each setting the right display on the Audio Analyzer should read within the limits indicated DC Voltage Limits Vdc DC Standard Voltage Vdc Performance Test 2 4 13 Performance Tests Model 8903B Performance Test 3 DISTORTION AND NOISE PERFORMANCE TEST Specification Characteristic Performance Limits Conditions SYSTEM DISTORTION Residual Noise and Distortion SIGNAL TO NOISE Residual Noise SOURCE OUTPUT LEVEL Residual Noise and Distortion MEASUREMENT DISTORTION AND SINAD Residual Noise and Distortion Description The higher of 80 dB or 17 V The higher of 70 dB or 50 V The higher of 65 dB or 50 aV The higher of 85 dB or 17 uV The higher of 70 dB
61. kHz Low pass Filter 3 dB Cutoff Frequency Rolloff 30 2 kHz 3rd order response 18 dB octave or 60 dB decade 80 kHz Low pass Filter 3 dB Cutoff Frequency Rolloff 80 4 kHz 3rd order response 18 dB octave or 60 dB decade 1 18 rev 30DEC88 Model 8903B General Information Table 1 1 Specifications 3 of 5 SYSTEM SPECIFICATIONS Cont d PLUG IN AUDIO FILTERS 400 Hz Highpass Filter 3 dB Cutoff Frequency Rolloff 400 40 Hz 7th order response 42 dB octave or 140 dB decade CCITT Weighting Filter CCITT Recommendation P53 Deviation from Ideal 20 to 55 80 relative humidity Response At 800 Hz 300 Hz to 3 kHz 50 Hz to 300 Hz 3 kHz to 3 5 kHz 3 5 kHz to 5 kHz CCIR Recommendation 468 2 DIN 45405 20 to 55 80 relative humidity 31 5 Hz to 63 Hz 63 Hz to 100 Hz 100 Hz to 200 Hz 200 Hz to 400 Hz 400 Hz to 800 Hz 800 Hz to 1 kHz 1 kHz to 6 3 kHz 6 3 kHz to 8 kHz 8 kHz to 9 kHz 9 kHz to 10 kHz 10 kHz to 12 5 kHz 12 5 kHz to 14 kHz 16 kHz to 20 kHz 20 kHz to 31 5 kHz at 31 5 kHz CCIR Weighting Filter Deviation from Ideal Response 2 0 dB 1 4 dB 1 0 dB 0 85 dB 0 7 dB 0 55 dB 0 5 dB 0 2 dB 0 4 dB 0 6 dB 0 8 dB 1 2 dB 1 65 dB 2 0 dB 2 8 inf dB C MESSAGE Weighting Filter Deviation from Ideal Response
62. mode stop in midsweep press the CLEAR key Pressing the SWEEP key again will reset and restart the sweep EXAMPLE 3 130 To sweep the source frequency from 100 Hz to 25 kHz Function Data Unit LOCAL keystrokes 2 5 Ga SWEEP FA1Q00HZFB25KZW1T0 x Function L Free Run Trigger Data Function program codes Unit Unit Function Data Sweep Model 8903B Operation PROGRAM CODES ex START FREQ FA STOP FREQ SWEEP OFF SWEEP ON kHz Hz NOTE Free Run triggering code TO is the only trigger mode allowed when using the sweep function code WI Any other triggering codes T1 T2 or or use of CLEAR key triggering will cause only the start frequency point to be displayed plotted and read to the HP IB Both the rear panel X AXIS and Y AXIS outputs will be inhibited from continuing beyond the start frequency point INDICATIONS When the START FREQ or STOP FREQ key is pressed the left display shows the currently programmed start or stop frequency and the source goes to that frequency As the new start or stop frequency is entered it will appear on the left display When the unit key is pressed the left display returns to show the input signal frequency The source remains at the start or stop frequency When the SWEEP key is pressed the LED within the SWEEP key will light The light indicates that the instrumen
63. on the right display between 99 70 and 100 3 Set the ac calibrator frequency to 100 kHz Adjust A2C92 for a reading between 99 50 and 100 5 Repeat steps 26 and 27 as often as needed until the flatness at 40 kHz and 100 kHz is within the limits given NOTE If the flatness cannot be adjusted so that the 40 kHz and 100 kHz readings are both within the given limits change A2C102 as follows If the 100 kHz reading is higher than at 40 kHz decrease A2C102 by approximately 10 If the 40 kHz reading is higher than that at 100 kHz increase A2C102 by approximately 10 On the Audio Analyzer press RATIO to turn it off Key in 1 4 SPCL to set the input to the 75 4V range Set the ac calibrator frequency to 1 kHz and level to 60 Vrms The right display of the Audio Analyzer should read between 58 8 and 61 2V Press RATIO Set the ac calibrator frequency to 40 kHz Adjust A2C110 LOW 40 DB for a reading on the right display between 99 70 and 100 396 Set the ac calibrator frequency to 100 kHz Adjust A2C110 for a reading between 99 50 and 100 5 Repeat steps 31 and 32 as often as needed until the flatness at 40 kHz and 100 kHz is within the limits given Perform the ac level accuracy portion of the AC Level Accuracy and Output Level Accuracy and Flatness Performance Test Performance Test 1 Adjustment 2 5 7 eT O Adjustments Model 8903B Adjustment 3 COMMON MODE REJECTION ADJUSTMENT Reference Service Sheet 1 Description
64. or 10 MHz reverse the vertical input and external trigger connections on the oscilloscope 3 Set the oscilloscope s vertical sensitivity to view the Audio Analyzer s time base reference or the frequency standard output Set the horizontal scale for 0 1 ys per division Set the oscilloscope to trigger externally 4 Adjust A8C27 Serial Prefix 2922A and below A8C41 Serial Prefix 2948A and above for a waveform movement of 10 divisions per second or less A totally non metallic adjustment tool is recommended NOTE A movement of the waveform to the right or left if the oscilloscope connec tions are reversed at a rate of one division per second means that the Audio Analyzer s time base frequency is low by 0 1 ppm 5 4 Adjustment rev 20JUN91 Model 8903B Adjustments Adjustment 2 INPUT FLATNESS ADJUSTMENT Reference Service Sheet 1 Description An ac calibrator is connected to the high input of the Audio Analyzer The Audio Analyzer is set to measure ac level The frequency of the calibrator is varied between 1 40 and 100 kHz and the flatness adjusted for a constant level at all three frequencies The procedure is then repeated with the ac calibrator connected to the low input Voltages up to 60 Vrms will be applied to the Audio Analyzer s input connectors and will be present on the assembly being adjusted Do not extend the assembly or probe its circuitry when high voltage is applied to the input Equ
65. program codes For example the right display reads 147 decimal which equals 1001 0011 in binary Now obtain the fine tune data Code _ s Functions LOCAL SPCL keystrokes 5 7 qa B program codes For example the right display reads 128 decimal which equals 1000 0000 in binary Now combine the data into the required five byte sequence Range 55 SPCL 1 decimal 0001 Coarse Tune 56 SPCL 147 decimal 1001 0011 MSD LSD Fine Tune 56 SPCL 128 Decimal 1000 0000 MSD LSD BYTE 1 BYTE 2 BYTE 3 BYTE 4 BYTE 5 yJ Coarse Tune Fine Tune Range m 0011 BBBB 0011 BBBB 0011 BBBB 0011 BBBB 0011 LSD MSD LSD MSD 0011 1001 0000 1000 0001 MERE d d d 0011 0011 0011 1001 0011 0000 0011 1000 0011 0001 BYTE 1 BYTE2 BYTE 4 5 ASCI 3 ASCII 9 ASCII 0 ASCII 8 ASCII 1 Rapid Source 3 109 Model 8903B To select the Audio Analyzer s Rapid Source mode issue the HP IB code RS To tune the Audio Analyzer to 1 kHz in the Rapid Source mode issue the ASCII string 39081 Using a Hewlett Packard Model 85B Desktop Controller issue the command OUTPUT 728 RS39081 Using a Hewlett Packard Model 9825A Desktop Controller issue the command wrt 728 RS39081 When using a series of Rapid Source mod
66. repair the instrument Sections 1 through 5 are bound in this volume the Operation and Calibration Manual One copy of the Operation and Calibration Manual is supplied with the instrument Sections 6 through 8 are bound in two separate volumes the Service Manual Copies of the Service Manual are not supplied with the instrument unless specifically requested as Option 915 at time of instrument order Copies of all volumes can be ordered separately through your nearest Hewlett Packard office The part numbers are listed on the title page of this manual Also listed on the title page of this manual below the manual part number is a microfiche part number This number may be used to order 100 x 150 mm 4 x 6 inch microfilm transparencies of this manual Each microfiche contains up to 96 photo duplicates of the manual s pages The microfiche package also includes the latest MANUAL UPDATES packet as well as all pertinent Service Notes 1 2 SPECIFICATIONS Instrument specifications are listed in Table 1 1 These are the performance standards or limits against which the instrument may be tested Characteristics listed under Supplemental Information Table 1 2 are not warranted specifications but are typical characteristics included as additional information for the user 1 1 General Information Model 8903B 1 3 SAFETY CONSIDERATIONS This product is a Safety Class I instrument that is provided with a protective earth terminal The Audi
67. the weighted conditions below 1 Data Ready 2 HP IB error 4 Instrument error The instrument powers up in the 22 2 state HP IB error Display Level in Watts Display level as watts into 80 19 0SP Display level as watts into NNN 19 NNNSP Source Output Impedance Instrument powers up at 60011 6009 500 3 40 Model 8903B m Operation Table 3 9 Commonly Used Code Conversions Hexa Binary Octal decimal 00 000 000 00 000 001 00 000 010 00 000 011 00 000 100 00 000 101 00 000 110 00 000 111 00 001 000 00 001 001 00 001 010 00 001 011 00 001 100 00 001 101 00 001 110 00 001 111 00 010 000 00 010 001 00 010 010 00 010 011 00 010 100 00 010 101 00 010 110 00 010 111 00 011 000 00 011 001 00 011 010 00 011 011 00 011 100 00 011 101 00 011 110 00 011 111 00 100 000 00 100 001 00 100 010 00 100 011 00 100 100 00 100 101 00 100 110 00 100 111 00 101 000 00 101 001 00 101 010 00 101 011 00 101 100 00 101 101 00 101 110 00 101 111 00 110 000 00 110 001 00 110 010 00 110 011 00 110 100 00 110 101 00 110 110 00 110 111 00 111 000 00 111 001 00 111 010 00 111 011 00 111 100 00 111 101 00 111 110 00 111 111 SRE BRBIZ amp oon BS EM QD Co Wh Hexa Binary Decimal decimal 01 000 000 01 0
68. the DISTN key If the internal source is to be used as the stimulus signal key in the desired frequency and amplitude Use the filters to limit noise hum spurious signals etc The Audio Analyzer powers up with the LOW PASS 80 kHz filter activated EXAMPLE To measure the distortion of an external source in a 30 kHz bandwidth LOCAL 7 Measurement Filter LOW PASS keystrokes DISTN 30 kHz x M3L1 program codes TE jos Filter PROGRAM CODE um M3 is the HP IB code for the distortion measurement INDICATIONS When distortion is selected the LED within the DISTN key will light The frequency and distortion of the input signal are displayed and the appropriate annunciators are lighted see Description above 3 58 Distortion O Or a ee a Model 8903B Operation MEASUREMENT TECHNIQUE In the distortion measurement mode the controller automatically sets the input attenuation and the gain settings of various amplifiers This is accomplished by measuring the input signal with the rms range detector This control ensures that the signal amplitude is within the proper range for the input and output detectors The input detector converts the ac level of the combined signal noise distortion to dc The notch filter removes the fundamental signal The notch filter automatically tunes to the component whose frequency is measured by the counter usually the fundamenta
69. the HIGH OUTPUT to the HIGH INPUT through a 500 feedthrough termination 4 14 Performance Test 3 Model 8903B Performance Tests 2 Set the SOURCE frequency and amplitude and the MEASUREMENT mode and LP FILTER as indicated below For each setting the right display should be within the limits indicated For the DISTN measurement set LOG LIN to read in dB MEASUREMENT ME LP FILTER 1 1 000 1 000 1 000 1 000 20 000 50 000 50 000 50 000 100 000 100 000 100 000 DISTN DISTN DISTN DISTN DISTN SIG NOISE DISTN DISTN DISTN SIG NOISE DISTN DISTN DISTN Performance Test 3 4 15 Performance Tests Model 8903B Performance Test 4 DISTORTION SINAD AND SIGNAL TO NOISE ACCURACY PERFORMANCE TEST Specification SYSTEM 1 dB 50 Hz to 100 kHz SIGNAL TO NOISE 20 Hz to 20 kHz 20 kHz to 100 kHz Accuracy MEASUREMENT DISTORTION Accuracy SINAD 20 Hz to 20 kHz 20 kHz to 100 kHz Accuracy Description A signal with a known distortion level is artificially created by summing the output from the Audio Analyzer and the output from the Multifunction Synthesizer into the input of the Audio Analyzer The artificial distortion or noise is measured by the Audio Analyzer An external 20 dB attenuator is used to extend the dynamic range of the Multifunction Synthesizer output level Equipment Multifunction Synthesizer 3 ERES CERO E
70. the beginning of this section 2 Place a graph paper or a copy of the RIAA curve on the X Y recorder This procedure assumes that the measurement result is plotted on a copy of the RIAA curve Press the START FREQ key and use the zero controls on the X Y recorder to move the pen to the lower left corner of the graph The point where the 20 and 30 dB grid lines cross corresponds to the lower left corner Next press the STOP FREQ key and use the vernier controls on the X Y recorder to move the pen to the upper right corner of the graph the intersection of the 30 dB and 20 kHz grid lines Press the START FREQ key again to check the lower left corner point and readjust if necessary 3 Set the Audio Analyzer to measure ac level LOCAL keystrokes 4 Set the Audio Analyzer source to sweep from 20 Hz to 20 kHz The Audio Analyzer powers up with start and stop frequencies of 20 Hz and 20 kHz respectively keystrokes 2 GR ICI C 5 Set the Audio Analyzer upper and lower plot limit to 30 and 30 respectively UPPER LIMIT LOWER LIMIT LOCAL sat keystrokes o Ct 3 Lo 6 Select the desired sweep resolution using Special Function 17 The Audio Analyzer powers up with the sweep resolution set at 10 points per decade In this example there are three decades log 20000 20 3 so the maximum sweep resolution allowed is 50 points per decade X Y Recording 3 139
71. the numeric code is entered it will appear on the left display When the SPCL key is pressed the display returns to show the input signal frequency When Special Function code 6 1 is entered and the SPCL key is pressed the LED within the SPCL key will turn on The LED will not turn on for Special Function code 6 0 When the HP IB codes NO or N1 are used there is no numeric code shown in the left display Notch Tune 3 93 Model 8903B COMMENTS When the Audio Analyzer first powers up or when AUTOMATIC OPERATION is selected the Audio Analyzer is placed in the automatic notch tuning mode In the automatic tuning mode the Audio Analyzer counts the frequency of the input signal then coarsely tunes the notch filter to that frequency The notch filter is then fine tuned via circuitry internal to the notch filter In the hold tune mode the notch filter is no longer coarsely tuned however the fine tune circuitry still remains operational Thus the notch filter still automatically tunes but now over a limited range In the hold tuning mode the tuning or nulling range of the notch filter is approximately 5 of the frequency of the original notch filter setting RELATED SECTIONS Automatic Operation Distortion Distortion Level SINAD Special Functions 3 94 Notch Tune aa O 8903B Operation Output Impedance DESCRIPTION The Audio Analyzer source has two selectable output impedances 500 or 6000 This
72. the second Programmable Gain Amplifier drives the rear panel MONITOR output connector The frequency of this signal is also measured by the Counter in the ac level and signal to noise ratio measurement modes because of the increased sensitivity at this point The Output Detector is read by the dc voltmeter in the ac level SINAD the denominator distortion the numerator distortion level and signal to noise ratio measurement modes It is also used to set the Model 8903B General Information gain of the two Programmable Gain Amplifiers Both the input and output detectors can be configured via special functions to respond to the absolute average of the signal instead of the true rms value In the SINAD mode the outputs from the Input RMS Average and Output RMS Average Quasi peak Detectors are converted to a current representing the log of the ratio of the two signals by the SINAD Meter Amplifier to drive the SINAD panel meter Since SINAD measurements are often made under very noisy conditions the panel meter makes it easier to average the reading and to discern trends The Voltage to Time Converter converts the dc inputs into a time interval which is measured by the Counter The Output Detector can also be configured via special functions to respond to the quasi peak of the signal This type of detector is designed to respond to impulse type signals better than other types The Quasi peak Detector has a fast rise time coupled with
73. voltmeter The output of this detector is used to set the gain of the input circuits The signal then passes through the HP BP filters to the Input RMS Average Detector and becomes the numerator of the SINAD measurement and the denominator of the distortion measurement refer to Basics of Audio Measurements The Input RMS Average Detector is not used to make the ac level measurement the Output RMS Average Quasi peak Detector is used for this measurement For dc level measurements the Ranging RMS Detector also monitors the ac component if there is one and lowers the gain of the input path if the signal will overload the input amplifiers otherwise the gain of the input path is determined by measuring the dc level At this point one of the two internal plug in filters can be inserted into the signal path The 400 Hz high pass filter is usually used to suppress line hum or the low frequency squelch tone used on some mobile transceivers The weighting filters have bandpass frequency responses that simulate the average response of human hearing In the SINAD distortion and distortion level modes the frequency of the input signal is counted at the output of the internal plug in HP BP Filters When measuring SINAD distortion or distortion level the fundamental of the signal is removed by the Notch Filter The output from the filter is the distortion and noise of the signal In the ac level and signal to noise ratio modes the Notch Filter is bypassed
74. will be inhibited from continuing beyond the start frequency point M uU Model 8903B GED Operation Hold T1 This mode is used to set up triggered measurements initiated by program codes T2 or T3 the Trigger message or the CLEAR key In Hold mode internal settings can be altered by the instrument itself or by the user via the bus Thus the signal at the MONITOR output can change However the instrument is inhibited from outputting any data to the front panel key lights and display to the rear panel X AXIS or Y AXIS outputs or to the HP IB except as follows The instrument will issue the Require Service message if an HP IB code error occurs The instrument will issue the Status Byte message if serial polled A serial poll however will trigger a new measurement update displays and return the instrument to Hold Upon leaving Hold the front panel indications are updated as the new measurement cycle begins The Status Byte will be affected and the Require Service message issued by the events that occur during the new measurement cycle The Audio Analyzer leaves Hold when it receives either the Free Run Trigger Immediate Trigger with Settling codes or the Trigger Message when the CLEAR key is pressed if not in Local Lockout or when it returns to local operation Trigger Immediate T2 When the Audio Analyzer receives the Trigger Immediate code it makes one measurement in the shortest possible time The instrument then waits
75. with the instrument to convert the BNC input and output to a dual banana connector with standard 3 4 inch spacing The adapters connect the conductor of the banana connector to the center conductor of the BNC connector These adapters are normally used when the FLOAT switches are set in the FLOAT position 89038 SOURCE 8903B INPUT DEVICE UNDER TEST Lnd Re Rc CONDUCTOR COMMON CONDUCTOR RESISTANCE LINE RESISTANCE 50 600 Effect of Multipoint Ground System FLOAT Switch Closed 3 72 Float es Se es O Model 8903B Operation One major source of error which must be considered when measuring low level ac signals or when making low distortion measurements is error introduced by ground loops The previous illustration illustrates a typical measurement setup using the Audio Analyzer In the figure the system common line is connected to chassis or earth ground at two separate points the chassis of the Audio Analyzer and the common point of the device under test Since two physically separate ground points are seldom at the same ground potential current will flow in the system common line Due to conductor resistance RC in the system common line the current causes a voltage drop This voltage drop a common mode voltage sums with the signal under measurement and can cause erroneous readings Grounding the system common line at a single point minimizes the effect of common mode voltages caused by ground loops Floating the Audio Anal
76. 0 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 4 4 Performance Test 1 Model 8903B Performance Tests AC Calibrator Ratio Limits 9 5 Special Level Frequency Paci qme Minimum Mains 100 000 96 50 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 50 000 100 000 100 000 50 000 20 000 1 000 20 Performance Test 1 4 5 Performance Tests Model 8903B 4 6 High Level Low Input AC Level Accuracy 3 Set the INPUT switch to FLOAT Connect the output of the ac calibrator to the LOW INPUT of the Audio Analyzer Short the HIGH INPUT to ground 4 On the Audio Analyzer key in the Special Functions indicated in the table below Set the ac calibrator to the level indicated in the table Use the high voltage amplifier where needed On the Audio Analyzer key in the same voltage and press RATIO Now set the ac calibrator to the frequency indicated in the table The right display of the Audio Analyzer should read within the limits indicated AC Calibrator Ratio Limits c Level Frequency Vrms Hz 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000
77. 0 1V 0 2V 0 50 wW 2V 3V SY sov 100V 200V 500v 1000 300v DIFFERENTIAL INPUT VOLTAGE CASE 1 Single Ended Source with Common Mode on Both Lines Common Mode Model 8903B VHIGH VDIFF 8903 INPUT VLOW Vd 2 OPERATING REGION FOR VALID MEASUREMENTS INSTRUMENT IN AUTOMATIC OPERATION COMMON MODE INPUT VOLTAGE 1 20mV SOmv 50V 100V 200v 500V 1000V 300V DIFFERENTIAL INPUT VOLTAGE CASE 2 Balanced Source with Common Mode on Both Sides RELATED SECTIONS AC Level DC Level Common Mode 3 49 SS Gi gt gt ss Operation Model 8903B DC Level DESCRIPTION The DC LEVEL key causes the Audio Analyzer to measure the differential dc voltage between its HIGH and LOW INPUT connectors Signals that are common to both the HIGH and LOW connectors are rejected PROCEDURE make a dc level measurement press the S Shift key then the DC LEVEL key The voltage can be expressed in either volts or if the voltage is positive in dBm that is dB relative to 1 milliwatt into 6000 To obtain a display in dBm press the LOG LIN key To return to linear simply press the LOG LIN again If the dc level is to be displayed relative to a reference level refer to RATIO and LOG LIN EXAMPLE measure the dc level at the INPUT connectors LOCAL keystrokes zx program codes Measurement PROGRAM CODE _
78. 0 Hz to 100 kHz and from 50 mV to 300V PROCEDURE Set the internal source to the desired frequency and amplitude Press the S Shift key and then the SIG NOISE key EXAMPLE make a signal to noise measurement at 1V and 1 kHz 7 Functions Data Unit D Function Data Unit Measurement LOCAL keystrokes Om Ug APIVLFER1KZS2 x Function___ L Measurement d Data Unit program codes Unit Data Function PROGRAM CODES x S2 is the HP IB code for the signal to noise measurement Signal to Noise Model 8903B Operation INDICATIONS When signal to noise is selected the LEDs in the S Shift and the SIG NOISE keys will light The appropriate signal to noise information is displayed MEASUREMENT TECHNIQUE In the signal to noise measurement mode the controller automatically sets the input attenuation and the gain settings of various amplifiers This control ensures that the signal amplitude is within the proper range for the output detector In addition the controller alternately turns the oscillator on and off for each measurement The output detector converts the two ac signals signal noise and noise to dc The dc voltmeter measures the dc The controller then corrects for the gain and attenuation computes the ratio and displays the results in the appropriate units The frequency of the input signal is also measured and displayed COUNTER LEFT DISPLAY
79. 00 001 01 000 010 01 000 011 01 000 100 01 000 101 01 000 110 01 000 111 01 001 000 01 001 001 01 001 010 01 001 011 01 001 100 01 001 101 01 001 110 01 001 111 01 010 000 01 010 001 01 010 010 01010 011 01 010 100 01 010 101 01 010 110 01 010 111 01 011 000 01 011 001 01 011 010 01 011 011 01 011 100 01 011 101 01 011 110 01 011 111 01 100 000 01 100 001 01 100 010 01 100 011 01 100 100 01 100 101 01 100 110 01 100 111 01 101 000 01 101 001 01 101 010 01 101 011 01 101 100 01 101 101 01 101 110 01 101 111 x HT OCOD ECN Imo COZZrF XcCc I ommo ouon p 01 110 000 q Q1 110 001 r 01 110 010 01 110 011 01 110 100 01 110 101 01 110 110 01 110 111 01 111 000 01 111 001 01 111 010 01 111011 01 111 100 01 111 101 01 111 110 01 111 111 lt ON OX 3 41 a et Operation m Model 8903B AC Level DESCRIPTION The Audio Analyzer contains a wideband true rms and average responding voltmeter with high accuracy and sensitivity The AC LEVEL key causes the Audio Analyzer to measure the differential ac voltage between its HIGH and LOW INPUT connectors Signals that are common to both the HIGH and LOW connectors are rejected PROCEDURE To make an ac level measurement press the AC LEVEL
80. 1 DISTN 50 99 900 99 895 99 905 AC LEVEL 5 99 900 99 895 99 905 AC LEVEL 5 150 00 149 980 150 020 Source Frequenc Hz 20 20 06 200 200 6 2 000 2 006 20 000 20 060 100 000 100 300 AUDIO FILTERS PERFORMANCE TEST High Pass and Low Pass Filters Initial SOURCE Frequency Setting Hz 400 Hz HP 30 Hz LP 80 Hz LP 440 Hz 32 000 Hz 84 000 Hz 400 30 000 80 000 Option 010 or 050 SOURCE Frequency Hz CCITT Weighting Filter Option 011 or 051 50 100 200 300 500 800 1 000 2 000 3 000 3 500 5 000 28 000 Hz 76 000 Hz 8908 Performance Tests Table 4 1 Performance Test Record 10 of 12 Test Test Description AUDIO FILTERS PERFORMANCE TEST Cont d CCIR Weighting Filter Option 012 or 052 31 5 63 100 200 400 800 1 000 2 000 3 150 4 000 9 000 6 300 7 100 8 000 9 000 10 000 12 500 14 000 16 000 20 000 31 500 C Message Weighting Filter Option 013 or 053 60 100 200 300 400 500 600 700 800 900 1 000 1 200 1 300 1 500 1 800 2 000 2 500 2 800 3 000 3 300 3 500 4 000 4 500 5 000 31 9 dB 25 3 dB 20 8 dB 14 65 dB 8 5 dB 2 45 dB 0 5 dB T 5 1 dB 8 5 dB 10 0 dB 11 2 dB 4 12 0 dB 11 8 dB 11 0 dB 9 5 dB 7 3 dB 1 2 dB 6 7 dB 13 35 dB 24 2 dB 27 9 dB 22 5 dB 18 8 dB 12 95 dB 7 1 dB 1 35 dB 0 5 d
81. 1 000 20 20 1 000 20 000 50 000 100 000 100 000 50 000 20 000 1 000 20 High Level Low Input Level Accuracy Level Low Input AC Level Accuracy 1 1 300 20 1 000 20 000 100 000 1 2 150 100 000 20 000 1 000 20 1 3 100 20 1 000 20 000 100 000 4 32 Model 8903B Performance Tests Table 4 1 Performance Test Record 4 of 12 eon Minimum Maximum AC LEVEL ACCURACY AND OUTPUT LEVEL ACCURACY AND FLATNESS PERFORMANCE TEST High Level Low Input AC Level Accuracy AC Calibrator Level nction Vrms 70 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 4 33 Performance Tests Model 8903B No 4 34 Table 4 1 Performance Test Record 5 of 12 AC LEVEL ACCURACY AND OUTPUT LEVEL ACCURACY AND FLATNESS PERFORMANCE TEST High Level Low Input AC Level Accuracy AC Calibrator Level Frequency Vrms Hz 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 Special Function
82. 30 NOTE Free Run triggering code is the only trigger mode allowed when using the sweep function code W1 Any other triggering codes T1 T2 or or use of CLEAR key triggering will cause only the start frequency point to be displayed plotted and read to the HP IB Both the rear panel X AXIS and Y AXIS outputs will be inhibited from continuing beyond the start frequency point Reading Data from the Right or Left Display The Audio Analyzer can only read data to the HP IB once for each measurement made Only the information on one display can be read each time Use the codes RR read right display or RL read left display to control which information is read The display will remain selected until the opposing display is specified or until a clear message is received or power up occurs Errors which occupy two displays are output as described above and DC LEVEL measurement results always occupying the right display only are placed on the bus when requested regardless of which display is enabled Program Order Considerations Although program string syntax is virtually identical to keystroke order some program order considerations need highlighting Automatic Operation AU As in local mode when AUTOMATIC OPERATION is executed in remote it sets all Special Functions prefixed 1 through 8 to their zero suffix mode and also affects many other Special Functions Thus when AUTOMATIC OPERATION is used it should appear at th
83. 31 5 Hz 31 5 Hz to 50 Hz 50 Hz to 4 kHz 4 kHz to 6 3 kHz 6 3 kHz to 8 kHz 8 kHz to 10 kHz 10 kHz to 12 5 kHz 12 5 kHz to 26 kHz The output of the Audio Analyzer is connected to the input At various frequencies the ac level of the output is measured with the audio filters in and out The ratio of the two levels is the frequency response of the filter at that frequency 4 22 Performance Test 6 Model 8903B Performance Tests Procedure 1 Key in 41 0 SPCL to initialize the instrument Set the INPUT and OUTPUT switches both to ground Connect the HIGH OUTPUT to the HIGH INPUT Set AMPTD to 2V and LOG LIN to LOG 2 Set the SOURCE frequency as indicated below For each setting perform the following procedure a Set all filters off Set RATIO off b Set RATIO on Set in the filter indicated below c Note the dB ratio If it is not between 3 1 and 2 9 dB increment or decrement the SOURCE frequency slightly until the indicated level is correct The displayed frequency should be within the limits indicated Frequency Limits Hz Initial SOURCE Frequency Setting Hz High Pass or Low Pass Filter 400 Hz HP 30 kHz LP 80 kHz LP Option 010 or 050 8 Key in 48 1 SPCL to enable up ranging of the gain following the filters Set the SOURCE frequency as indicated below in the table appropriate for the installed weighting filter For each setting perform the following procedure
84. 41 0 SPCL to initialize the instrument Set the INPUT and OUTPUT switches both to ground Set the 80 kHz LOW PASS FILTER off Connect the ac calibrator to the Audio Analyzer s HIGH INPUT 2 On the Audio Analyzer key in the Special Functions indicated in the table below Set the ac calibrator to the level indicated in the table Use the high voltage amplifier where needed On the Audio Analyzer key in the same voltage and press RATIO Now set the ac calibrator to the frequency indicated in the table The right display of the Audio Analyzer should read within the limits indicated NOTE Record the readings in the tables Many of the readings will be used as calibration factors in later steps If the ac calibrator is unable to drive the input capacitance of the Audio Analyzer and input cable at high frequencies and voltages then reduce the level as needed AC Calibrator Ratio Limits Level Frequency Vrms Hz 300 20 98 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 100 000 Special Function Performance Test 1 4 3 Performance Tests Model 8903B AC Calibrator Ratio Limits Uo Special Level Frequency 104 20 20 1 000 20 000 100 000 100 000 20 000 1 000 20 20 1 000 20 000 50 000 100 000 100 000 20 000 1 000 20 20 1 000 2
85. 500 points decade 17 9 SPCL EXAMPLE To set the sweep resolution to 100 points decade s Code Function LOCAL keystrokes program codes NS pem PROGRAM CODES x For HP IB codes refer to Procedure above Sweep Resolution 3 133 Model 8903B INDICATIONS the numeric code is entered it will appear on the left display When the SPCL key is pressed the left display returns to show the input signal frequency Unless Special Function code 17 0 was entered the light within the SPCL key will turn on if not already on If the light is already on it will remain on COMMENTS The maximum number of points in a sweep is restricted to 255 points T herefore if a sweep resolution of 500 points decade is required the sweep span has to be limited to approximately half a decade The frequency points in a sweep can be computed by using the following formulas Enter Frequency START FREQ x 107 Where n the frequency point number and n 0 is for the start frequency k number of points per decade For reverse sweep the frequency point formula becomes Enter Frequency START FREQ x 1077 The following example illustrates how to compute the frequency points for a 50 Hz to 30 kHz sweep with a sweep resolution of 5 points decade Special Function code 17 3 1 Compute the sweep range in decades using the formula sweep range in decades log START E RED For this example sweep r
86. ATED SECTIONS Amplitude Frequency Increment 3 85 Operation Model 8903B Input Level Range DC Level Special Function 2 DESCRIPTION In all measurement modes the input level range can be manually set by keyboard entry using the SPCL key The following discussion describes this function for dc level mode only Refer to Input Level Range Except DC Level for additional information In the automatic operation mode the input level range is determined by both the dc and ac if there is one level of the input signal PROCEDURE To set the input level range to a selected range or to re enter the automatic selection mode key in the corresponding Special Function code then press the SPCL key Input Level Range Input Special Function Program Code Full Scale Attenuation Code m Automatic Selection 2 0 SPCL 300V range 2 1 SPCL 64V range 2 2 SPCL 16V range 2 3 SPCL 4V range 2 4 SPCL EXAMPLE To set the input level range to the 16V range Code Function LOCAL keystrokes 2 Eu 3 program codes MS Le unction PROGRAM CODE x For HP IB codes refer to Procedure above INDICATIONS the numeric code is entered it will appear on the left display When the SPCL key is pressed the left display blanks out Note that for all measurement modes except dc level the left display will return to show the input signal frequency after the SPCL key is pressed Unless Special F
87. Agilent Technologies Inc WWW agilent com 24001 E Mission Liberty Lake WA 99019 fy Agilent Technologies t Innovating the HP Way June 8 2000 Dear Customer As of November 1 1999 four of Hewlett Packard s businesses test and measurement semiconductor products health care solutions and chemical analysis became a new company Agilent Technologies Now many of your Hewlett Packard products and services are in the care of Agilent Technologies At Agilent Technologies we are working diligently to make this transition as smooth as possible for you However as a result of this transition the products and related documentation contained in this shipment may be labeled with either the Hewlett Packard name and logo the Agilent Technologies name and logo or a combination of both Information in this package may refer to Hewlett Packard HP but applies to your Agilent Technologies product Hewlett Packard and Agilent branded products with the same model number are interchangeable Whatever logo you see the information products and services come from the same reliable source If you have questions about Agilent Technologies products and services please visit our website at http www agilent com Sincerely Rebranding Team 8903 AUDIO ANALYZER Including Option 001 Operation and Calibration Manual SERIAL NUMBERS This manual applies directly to instruments with serial numbers prefixed 2450A t
88. Audio Analyzer should read between 14 7 and 15 3V Press RATIO 10 Set the ac calibrator frequency to 40 kHz Adjust A2C10 HIGH 24 DB for a reading on the right display between 99 70 and 100 3 11 Set the ac calibrator frequency to 100 kHz Adjust A2C10 for a reading between 99 50 and 100 596 Repeat steps 10 and 11 as often as needed until the flatness at 40 kHz and 100 kHz is within the limits given NOTE If the flatness cannot be adjusted so that the 40 kHz and 100 kHz readings are both within the given limits change A2C9 as follows If the 100 kHz reading is higher than at 40 kHz decrease A2C9 by approximately 10 If the 40 kHz reading is higher than that at 100 kHz increase A2C4 by approximately 10 12 On the Audio Analyzer press RATIO to turn it off Key in 1 4 SPCL to set the input to the 75 4V range 13 Set the ac calibrator frequency to 1 kHz and level to 60 Vrms 14 The right display of the Audio Analyzer should read between 58 8 and 61 2V Press RATIO 15 Set the ac calibrator frequency to 40 kHz Adjust A2C109 HIGH 40 DB for a reading on the right display between 99 70 and 100 3 16 Set the ac calibrator frequency to 100 kHz Adjust A2C109 for a reading between 99 50 and 100 5 Repeat steps 15 and 16 as often as needed until the flatness at 40 kHz and 100 kHz is within the limits given Low input Flatness 17 Set the ac calibrator to 1 kHz at 4 5 Vrms 18 On the Audio Analyzer key in 41 0 SPCL to init
89. B 6 1 dB 9 5 dB 11 0 dB 12 2 dB 12 4 dB 12 2 dB 4 11 8 dB 10 7 dB 8 9 dB 1 2 dB 3 9 dB 10 05 dB 20 2 dB 39 9 dB 53 7 dB 40 5 dB 23 0 dB 15 5 dB 10 4 dB 6 5 dB 3 7 dB 1 7 dB 0 5 dB 0 4 dB 0 2 dB 0 8 dB 0 5 dB 0 0 dB 0 3 dB 0 3 dB 0 4 dB 0 9 dB 1 5 dB 3 2 dB 5 6 dB 11 5 dB 18 5 dB 25 5 dB 4 39 Performance Tests Model 8903B Table 4 1 Performance Test Record 11 of 12 AUDIO FILTERS PERFORMANCE TEST Cont d SOURCE Frequency Hz Cont d CCIR ARM Weighting Filter Option 014 or 054 31 5 37 5 dB 63 30 9 dB 100 26 4 dB 200 20 25 dB 400 14 1 dB 800 8 05 dB 1 000 6 1 dB 2 000 0 5 dB 3 150 2 9 dB 4 000 4 4 dB 5 000 4 5 6 dB 6 300 6 4 dB 7 100 6 2 dB 8 000 5 4 dB 9 000 3 9 dB 10 000 1 7 dB 12 500 6 8 dB 14 000 12 3 dB 16 000 18 95 dB 20 000 29 8 dB 31 500 A Weighting Filter Option 015 or 055 20 25 31 5 40 50 63 80 100 125 160 200 290 315 400 500 630 800 4 40 Model 8903B Performance Tests Table 4 1 Performance Test Record 12 of 12 Pos Test Description Minimum A Weighting Filter Option 015 or 055 Cont d 3 150 4 000 5 000 6 300 8 000 10 000 12 500 16 000 20 000 INPUT AND OUTPUT IMPEDANCE PERFORMANCE TEST Output Impedance 6009 502 49 90 49 00 50 40 51 00
90. B address in decimal Enable a condition to cause a service request N is the sum of any combination of the weighted conditions below 1 Data Ready 2 HP IB error 4 Instrument error Service Request HP IB Service Request Condition The instrument powers up in the 22 2 state HP IB error 6000 Source 47 0 47 0SP Output Impedance 500 Source Output impedance 47 1 47 1SP N No Not Applicable Y Yes Except the LCL S Shift and Numeric Keys Special Functions 3 127 Model 8903B PROCEDURE Entering Special Functions To use a Special Function key in the corresponding code then press the SPCL key Special Display To display the user requested modes of Special Functions 1 through 8 press the SPCL key alone one time The digit position noted beneath the displays corresponds to the Special Function prefix and the number displayed in that position corresponds to the Special Function suffix Special Special Display To determine the actual instrument settings of functions prefixed 1 through 8 press the SPCL key alone once while Special Display is active If the Special Display described above is not in effect press the SPCL key twice to get this display The digit position corresponds to the function prefix and the number displayed in that digit corresponds to tbe function suffix EXAMPLES 3 128 Entering Special Functions To display the frequ
91. EMOTE and ADDRESSED annunciators on its front panel will turn on Local Mode Local Capability In local the Audio Analyzer s front panel controls are fully operational and the instrument will respond to the Remote message Whether addressed or not it will also respond to the Clear Local Lockout Clear Lockout Set Local and the Abort messages When addressed to talk the instrument can issue Data messages and the Status Byte message and whether addressed or not it can issue the Require Service message Remote to Local Mode Changes The Audio Analyzer always switches to local from remote whenever it receives the Local message GTL or the Clear Lockout Set Local message The Clear Lockout Set Local message sets the Remote Enable control line REN false If it is not in Local Lockout mode the Audio Analyzer switches to local from remote whenever its front panel LCL key is pressed Addressing The Audio Analyzer interprets the byte on the bus eight data lines as an address or a bus command if the bus is in the command mode attention control line AT N true and interface clear control line IFC false Whenever the Audio Analyzer is being addressed whether in local or remote the ADDRESSED annunciator on the front panel will turn on The Audio Analyzer talk and listen addresses are switch selectable as described in Section 2 Refer to Table 2 1 for a comprehensive listing of all valid HP IB address codes To determine the present addres
92. EO ROO RES se RA RR Rd wat cd HP 8904A 20 dB Fixed Attenuator 500 Texscan FP 50 20dB or equivalent HP 8904A HP 8903B MULTIFUNCTION AUDIO ANALYZER pooaomnmnadacru ncmoooaoocdo oooo cooocuoaaaodo 2000 OUTPUT 1 HIGH Figure 4 1 Distortion SINAD and Signal to Noise Accuracy Test Setup 4 16 Performance Test 4 15 88 Model 8908 Performance Tests Procedure NOTE Do NOT insert the 20 dB attenuator between the output of the Multifunc tion Synthesizer and the input of the Audio Analyzer until Step 9 1 Connect the equipment as shown in Figure 4 1 2 On the Multifunction Synthesizer press SHIFT PRESET After the instrument presets key in 1 Channel Config NEXT Channel A SHIFT FLOAT 1 OFF AMPTD 0 V 3 On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Set the Audio Analyzer as follows NOTE To select 500 source impedence for Audio Analyzers with Serial Prefix 2742A and above key in 47 1 SPCL OUTPUT Switch RETE a se REESE vbique es ground ground OUTPUT IMPEDANCE See note above 500 SOURCE AMPTD rie eb dud otra datu Gira ei eee 6V PEE LOG 4 On the Audio Analyzer press RATIO The right display should indicate 0 00 dB 5 On the Audio Analyzer set the AMPTD to 6 On the Multifunction
93. Error Disable Disable both analyzer amp source errors PROGRAM CODES x HP IB Codes for the Special Functions are summarized in the Special Function Summary above INDICATIONS Entering Special Functions As the numeric code is entered both displays will blank and the entered code will appear in the left display When the SPCL key is pressed both displays will again blank and four dashes will momentarily appear in the right display These dashes are replaced with the appropriate reading for the selected measurement mode COMMENTS If a User Special Function prefixes 1 to 39 has a suffix of zero the zero need not be entered For example 10 0 SPCL equals 10 SPCL However 1 1 SPCL does not equal 1 10 SPCL If when entering a Special Function code Error 21 invalid key sequence is displayed the Special Function requested has not been executed Entry of invalid special function suffixes results in display of Error 23 For additional information on Direct Control Special Functions prefix 0 or Service Special Functions prefixes 40 to 99 refer to Section 8 RELATED SECTIONS Automatic Operation Default Conditions and Power up Sequence Special Function Summary table under Description above Special Functions 3 129 Operation Model 8903B Sweep DESCRIPTION The Audio Analyzer source frequency can be logarithmically swept The sweep range can be set between any two frequencies in the range of 20 Hz and 100 kHz The s
94. For serial prefix 2730A and below order HP part number 08903 60172 For serial prefix 2742A and above order HP part number 08903 60200 After installation and calibration performance will be identical to the standard HP 8903B 1 8 rev 26J UL89 Model 8903B General Information 1 11 MECHANICAL EQUIPMENT AVAILABLE Chassis Slide Mount Kit This kit is extremely useful when the Audio Analyzer is rack mounted Access to internal circuits and components or the rear panel is possible without removing the instrument from the rack Order HP part number 1494 0060 for 431 8 mm 17 in fixed slides and part number 1494 0061 for the correct adapters for non HP rack enclosures Chassis Tilt Slide Mount Kit This kit is the same as the Chassis Slide Mount Kit above except it also allows the tilting of the instrument up or down 90 Order HP part number 1494 0062 for 431 8 mm 17 in tilting slides and part number 1494 0061 for the correct adapters for non HP rack enclosures INTERNAL PLUG IN AC DC DIFFERENTIAL HP BP OVER TO SINGLE PROGRAMMABLE FILTERS PROGRAMMABLE PROGRAMMABLE PUT VOLTAGE ENDED GAIN GAIN GAIN ATTENUATOR PROTECTION AMPLIFIER 1 AMPLIFIER LP FILTERS AMPLIFIER HIGH M dP ps MONITOR OVEA o VOLTAGE PROTECTION PANG ANS Ci AC DC DETECTOR VOLTAGE CONVERTER oe RMS AVG COUNTER QUASI PEAK E o DETECTOR VOLTMETER A INPUT i SELECTOR TIME BASE RMS AVG SINAD METER T CH
95. ILTERS all off RATIO off SWEEP off Programming Numeric Data When programming source amplitude or frequency entering ratio references plot limits or issuing any numeric data other than specific HP IB codes to the Audio Analyzer certain precautions should be observed Numeric data may be entered in fixed floating 3 27 Operation m Model 8903B point or exponential formats Usually numeric data consists of a signed mantissa of up to five digits including leading zeros one decimal point and one or two digit signed exponent The decimal point may fall between any two digits of the mantissa but should not appear ahead of the first digit If it does a leading zero will be automatically inserted by the Audio Analyzer Any digit beyond the five allowed for the mantissa will be received as zero The general format for numeric data entry is given below followed by several examples illustrating various entries and the resulting data as received by the Audio Analyzer General Numeric Data Input Format DDDDDEtNN 5 Digit Signed prm Magnitude Mantissa Indicates Exponent Follows Exponent Sign Example 12345E 01 issued 0 12340E 01 received by Audio Analyzer Example 123456E 01 issued 123450E 01 received by Audio Analyzer Example 00012345 issued 12000 received by Audio Analyzer In general do not issue numeric data with more significant digits than can be displayed on the Audio Analyzer s left five d
96. NPUT TYPE 425V Peak Differentially applied or between either input and ground MAXIMUM INPUT INPUT IMPEDANCE Resistance 100 1 101 k 1 300 pF Except in dc level mode In dc level mode only Each terminal to ground Shunt Capacitance 20 Hz to 1 kHz Vin 2V 20 Hz to 1 kHz 20 Hz to 20 kHz The Hewlett Packard Interface Bus HP IB is Hewlett Packard Company s implementation of IEEE Std 488 1978 Digital Interface for Programmable Instrumentation Ali functions except the line switch the x 10 and 10 keys and the low terminal float ground switches are remotely controllable gt 60 dB gt 45 dB gt 30 dB HP IB STD 488 1978 Compatibility Code SH1 AH1 T5 TEO L3 LEO 591 RL1 _ PPO DC1 DT1 CO E1 COMMON MODE REJECTION RATIO REMOTE OPERATION POWER REQUIREMENTS Line Voltage 100 120 220 240 Vac 100 120 Vac 48 to 66 Hz 48 to 440 Hz 5 10 5 10 1 20 30 88 Model 8903B POWER DISSIPATION CONDUCTED AND RADIATED INTERFERENCE EMI CONDUCTED AND RADIATED SUSCEPTIBILITY NET WEIGHT DIMENSIONS Full Envelope Height Width Depth rev 30DEC88 General Information Table 1 1 Specifications 5 of 5 SYSTEM SPECIFICATIONS Cont d 100 A maximum MIL STD 461B MIL STD 461B 1980 12 3 kg 27 Ib 16 4 kg 36 Ib 146 mm 5
97. P T8 CONTROLLER CA DETECTOR AMPLIFIER Log CA snuo INSTRUMENT HARDNARE CONTROL COUNTER ni SCHMITT FLOATING I6GER OUTPUT OUTPUT OUTPUT EREI 2 5 KEYBOARD AND DISPLAY Figure 1 5 Simplified HP 8903B Audio Analyzer Block Diagram 1 12 RECOMMENDED TEST EQUIPMENT Table 1 3 lists the test equipment recommended for use in testing adjusting and servicing the Audio Analyzer If any of the recommended equipment is unavailable instruments with equivalent minimum specifications may be substituted Table 1 3 also includes some alternate equipment listings 1 13 PRINCIPLES OF OPERATION FOR SIMPLIFIED BLOCK DIAGRAM The HP 8903B Audio Analyzer combines three instruments into one a low distortion audio source a general purpose voltmeter with a tunable notch filter at the input and a frequency counter Measurements are managed by a microprocessor based Controller This combination forms an instrument that can make most common measurements on audio circuits automatically To add to its versatility the Audio Analyzer also has selectable input filters logarithmic frequency sweep x and y outputs for plotting measurement results vs frequency and HP IB programmability The operation of the instrument is described in the following order Voltmeter and Notch Filter Counter Source and Controller Refer to Figure 1 5 1 9 a es Se es O General Information Model 8903B Voltmeter and Notch Filter The amplitude measurem
98. PANEL FEATURES l x Figure 3 2 Rear Panel Features HP IB Connector connects the Audio Analyzer to Hewlett Packard Interface Bus for remote operations when in remote mode the front panel REMOTE annunciator lights MONITOR In ac level mode provides a scaled voltage output representing the input signal In SINAD distortion and distortion level modes provides a scaled voltage output of the input signal with the fundamental removed Output impedance is 6002 X AXIS A scaled voltage output representing the log of the oscillator frequency range from the start to the stop frequencies The start frequency equals 0V and the stop frequency equals 10V Output impedance is 1 Y AXIS scaled voltage output representing the amplitude range from the lower to the upper limit of the plot The lower limit equals The upper limits equals 10V Output impedance is 1 5 Fuse 1 5A rating for 100 120 Vac 1 0 rating for 220 240 Vac Line Power Module permits operation from 100 120 220 or 240 Vac The number visible in window indicates nominal line voltage to which instrument must be connected see Figure 2 1 Center conductor is safety earth ground PEN LIFT TTL compatible output that is used for pen control TTL high signal is used to lift pen Serial Number Plate First four numbers and letter comprise the prefix that denotes the instrument configuration The last five digits form the suffix that is uniqu
99. PUT IMPEDANCE SWITCH Model 8903B 6V maximum 500 V V L 502 500 s Vo 3V Ve R oao 10 log q mw 10 109 4 3 50 PdBmg 10 log PRA T PdBm 22 5 dBm Maximum Power Output into a 500 Load at 500 Output Impedance Vs 6V maximum 6009 L 500 6000 V 0 923 V V 5 54V 5 54 600 PdBmeo99 10 log IN PdBmggg 17 dBm Power Output into a 6009 Load at 509 Output Impedance 3 96 Output Impedance Model 8903B Operation s 6V maximum OUTPUT IMPEDANCE 6009 SW TOR i 6000 6000 6002 LOAD SAL x 3V 3 2 600 1 mW PdBmeo9 10 log 11 7 dBm Maximum power Output into a 6000 Load at 6000Output mpedance RELATED SECTIONS None Output Impedance 3 97 Ce et Se O Operation Model 8903B Plot Limit DESCRIPTION The PLOT LIMIT UPPER LIMIT LOWER LIMIT and the numeric data keys are used to program the upper and lower plot limits The upper and lower plot limits correspond to the respective upper and lower scaling points of an X Y plot For more information on X Y plots refer to X Y Recording The Y axis scaling is determined by the displayed measurement unit in the right display and the programmed upper and lower plot limit The PLOT LIMIT key can be also used to display the currently programmed upper and lower plot limits PROCEDURE To enter new plot
100. Record the measurement Multifunction Synthesizer Audio Analyzer Limits dB DISTN 9 4 SINAD 11 4 SINAD 81 0 DISTN 79 0 SIG NOISE 81 0 SIG NOISE 11 4 DISTN 9 4 DISTN 19 0 DISTN 29 0 DISTN 39 0 DISTN 49 0 DISTN 59 0 DISTN 69 0 DISTN T9 0 DISTN 79 0 DISTN 9 4 DISTN 9 4 DISTN 79 0 DISTN 79 0 DISTN 9 4 DISTN 9 4 SINAD 11 4 SIG NOISE 11 4 SIG NOISE 81 0 SINAD 81 0 DISTN 79 0 4 18 Performance Test 4 rev 15MAYS88 Model 8903B Performance Tests 10 On the Audio Analyzer set the 80 kHz LOW PASS FILTER off Repeat the previous step for the settings indicated below Audio Analyzer Limits dB Multifunction Synthesizer External 10 201 000 201 000 201 000 201 000 301 500 301 500 301 500 301 500 rev 15MAYS88 20 dB Atten 100 000 100 000 100 000 100 000 100 000 100 000 100 000 100 000 Performance Test 4 4 18 1 Model 8903B Performance Tests Performance Test 5 FREQUENCY ACCURACY AND SENSITIVITY PERFORMANCE TEST Specification SOURCE FREQUENCY Accuracy x 0 396 of setting MEASUREMENT FREQUENCY Measurement 20 Hz to 150 kHz AC level mode Range 20 Hz to 100 kHz Distortion SINAD and signal to noise modes Accuracy 0 00496 1 digit Sensitivity 50 mV Distortion and SINAD modes 5 mV AC level and signal to noise modes Description The frequency
101. Result Reading of Step b Minimum Actual Maximum 96 104 Synthesizer Frequency Hz 100 000 20 000 96 104 1 000 96 104 20 96 104 Performance Test 1 4 9 Performance Tests Model 8903B 4 10 Output Level Accuracy 9 Disconnect the audio synthesizer Connect the HIGH OUTPUT to the HIGH INPUT Key in 47 1 SPCL to set the Source impedance to 500 10 On the Audio Analyzer key in the special function source amplitude and source frequency listed in the table below For each setting perform the following procedure a Key in the source amplitude listed in the table as a ratio reference and press RATIO b Divide the displayed ratio by the result of step 2 corresponding to the same amplitude and frequency then multiply by 100 The computed result should be within the limits indicated Limits of Computed Results 0 EM Frequency 1 bs 20 000 50 000 100 000 100 000 50 000 20 000 1 000 20 20 1 000 20 000 50 000 100 000 100 000 20 000 1 000 20 Use the results for 7 Vrms in step 2 Special Function Performance Test 1 Model 8903B Performance Tests 11 On the Audio Analyzer set the source amplitude to 0 7 mV Key in 0 0007 RATIO Set the source frequency as listed in the table below For each entry divide the displayed result by the result of step 8 corresponding to the same frequency the
102. SCLAIMS THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE EXCLUSIVE REMEDIES THE REMEDIES PROVIDED HEREIN ARE BUYER S SOLE AND EXCLUSIVE REMEDIES HP SHALL NOT BE LIABLE FOR ANY DIRECT INDIRECT SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER BASED ON CONTRACT TORT OR ANY OTHER LEGAL THEORY ASSISTANCE Product maintenance agreements and other customer assistance agreements are available for Hewlett Packard products For any assistance contact your nearest Hewlett Packard Sales and Service Office Addresses are provided at the back of this manual Safety Considerations Model 8903B SAFETY CONSIDERATIONS GENERAL This product and related documentation must be re viewed for familiarization with safety markings and instructions before operation This product is a Safety Class I instrument provided with a protective earth terminal BEFORE APPLYING POWER Verify that the product is set to match the available line voltage and the correct fuse is installed SAFETY EARTH GROUND An uninterruptible safety earth ground must be pro vided from the main power source to the product input wiring terminals power cord or supplied power cord set SAFETY SYMBOLS Instruction manual symbol the product will be marked with this symbol when it is necessary for the user to refer to the instruction manual refer to Table of Contents 2 Indicates hazardous voltages al Indicates
103. Series 200 300 Controllers V SPOLL 728 Display the value of the SRQ bit in this step 6 is the SRQ bit numbered from 0 dsp SRQ bit 6 V Series 80 Controllers PRINT SRQ BIT V 7 Series 200 300 Controllers PRINT SRQ BIT V 6 Check that the SRQ value is 1 indicating the Audio Analyzer issued the Require Service message rev OSA 7690 3 21 Model 8903B Trigger Message and Clear Key Triggering Description This check determines whether or not the Audio Analyzer responds to the Trigger message and whether the CLEAR key serves as a manual trigger in remote This check assumes that the Audio Analyzer is able to handshake recognize its own address make the remote local changes and send and receive Data messages Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON then when the power up sequence is complete press the DISTN key Send the first part of the Remote message enabling Series 80 Controllers the Audio Analyzer to remote HEMOTE 7 Series 200 300 Controllers REMOTE 728 Address the Audio Analyzer to listen completing the wrt 728 T1 OUTPUT 728 T1 Remote message then send a Data message placing the Audio Analyzer in Hold mode Send the Trigger message trg 728 TRIGGER 728 Address the Audio Analyzer to talk and store the red 728 V ENTEH 728 V data in variable V Display the value of V dsp V PRINT V
104. Synthesizer set the AMPTD to 8 5 V Adjust the amplitude of the Multifunction Synthesizer for a reading of 0 00 dB on the Audio Analyzer Record the Multifunction Synthesizer AMPTD setting as Vref _______ mV 7 Use the recorded value of and the following formula to calculate the Multifunction Synthesizer amplitude Amptd mV The calculations using Atten dB 10 60 are then used in Step 9 Put the results for each level of attenuation on the lines provided below Multifunction Synthesizer AMPTD V 10 488 Multifunction Synthesizer Atten Amptd mV 10 20 30 40 50 60 rev 15MAYS88 Performance Test 4 4 17 Performance Tests Model 8903B 8 Set the Audio Analyzer as follows MEASUREMENT node EN DIST LOG LIN CENE LOG SOURCE AMPUD e ET tes R Ea aede 6V 9 Repetitively complete the following instructions for each measurement and record the results for the Actual limits in the following table a Set the Multifunction Synthesizer frequency to the value shown in the Freq Hz column b Set the Multifunction Synthesizer amplitude to the calculated value from step 7 for each level of attenuation shown in the Atten dB column Insert IN or remove OUT the external attenuator as indicated Set the Audio Analyzer frequency to the value shown in the Freq Hz column O e Set the Audio Analyzer to the function indicated in the Measurement Mode column f
105. T 3 Adjust A2R44 OFFSET for a steady reading of 0 00V on the right display Adjustment 4 5 9 Adjustments Model 8903B Adjustment 5 400 HZ HIGH PASS AND WEIGHTING BANDPASS FILTERS ADJUSTMENT Reference Service Sheet 2 2A and 2B Description The source output of the Audio Analyzer is connected to the input The source is set to a specified frequency and a level reference is set The filter to be adjusted is then inserted and its gain is adjusted for a level equal to the reference Procedure NOTE In the following procedures the leftmost filter circuit board is designated 2 1 and the rightmost board A2A2 The board location corresponds to option series 010 and 050 respectively 1 Key in 41 0 SPCL to initialize the instrument Set the INPUT and OUTPUT switches both to ground Connect the HIGH OUTPUT to the HIGH INPUT Set AMPTD to 1V 2 Perform the following steps for the filters installed 400 Hz High Pass Filter Option 010 or 050 a Set RATIO off Set FREQ to 2 kHz Set RATIO on b Press HIGH PASS 400 Hz Adjust A2A1R6 or A2A2R6 400 HZ for a reading between 99 60 and 99 80 on the right display c Set FREQ to 1 kHz The right display should read between 99 00 and 101 0 CCITT Weighting Filter Option 011 or 051 a Set HIGH PASS 400 Hz off if on Set FREQ to 800 Hz Set RATIO off then back on b Press CCITT WEIGHTING Adjust A2A1R4 or A2A2R4 CCITT for a steady reading of 100 0 on th
106. T FILTERS PROGRAMABLE PROGRAMABLE ATTENUATOR eee GAIN AMPLIFIER GAIN AMPLIFIER Po oo p WoNITOA 3 LOW PASS INPUT FILTERS OUTPUT AMPLIFIER RMS AVG QUASI PEAK DETECTOR Monitor Output Block Diagram COMMENTS The MONITOR output gain and sensitivity that is the net signal gain from the INPUT to the MONITOR output are dependent on the input stage gain and the post notch gain Both the input stage gain and the post notch gain can be determined by viewing the Special Special Display refer to Special Functions The input stage gain and post notch gain for various instrument settings are listed in the following tables 3 90 Monitor Model 8903B Special Special Display 1 NN Input Level Range 300V 189V 119V 75 4V 47 6V 30 0V 18 9V 11 9V 7 54V 4 76V 3 00V 1 89V 1 19V 0 754V 0 476V 0 300V 0 189V 0 119V 0 0754V INPUT STAGE GAIN Except dc Operation usu ue _ Log dB 0 20 40 60 1 10 100 1000 The measurement system net gain equals the combined gain of the two stages To calculate the net gain use the following formulas Or Net Gain LOG Input Stage Gain LOG Post Notch Gain LOG Net Gain LIN Input Stage Gain LIN X Post Notch Gain LIN In ac level the MONITOR output is a scaled replica of the input signal The MONITOR output level is calculated as Vout Vin X Net Gain where is the input signal level and the linear net gain is
107. TION When first turned on the Audio Analyzer performs a sequence of internal checks after which the instrument is ready to make measurements During the power up sequence all front panel indicators light to allow the operator to determine if any are defective After approximately four seconds this sequence is completed and the Audio Analyzer is preset as follows STARDIERBO God tetas ec Si ceases UP eC ruta iD E UM S 20 Hz STOP FREQ i ebrei beu ede xs d quede idu ME EE P LM ULL d LANE E IET 20 khZ PLOT LIMIT LOWER LIMIT oot oe hee wera rg 326 ua pea utat erbe endet deut s pei 100 0 UPPRECDIMILD Me rds ea 100 0 ERE M uL at 1000 0 Hz FREQ INCR ee d od CRI ea iuapP agis 1000 0 0 00 mV AMPTD INCR i eaters duae quie ape bt 0 100V MEASURE MEN adic ston cares eas cece EE AC LEVEL DETECTOR ix ates diu one a ees asia S oiu iU ptu eas RMS LP CT 22242268 end tee Beka LOW PASS 80 kHz dto ra Gantt a ek noe UR Sex ded Pay diss Off RATIO Etre Off Ratio Referen6ees anta des Aaa at 0 a a a er ts ac car eMe OE LIN Len LU sad ore diced ote dares Sank SS Soe ee Bare SEWER vata eae wos Inpu
108. The drop in level is a measure of the output or input impedance Equipment Feedthrough Termination 500 i oves Uu Race PAS RAO dr bn GA dons HP 11048C Feedthrough Termination 6000 rere a saw Sore ha uk ees a SOR wes HP 11095A Resistor 100 Ki cic esee a uai aod E ME p DEP d MPs HP 0698 7497 Procedure 1 On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Key in 1 11 SPCL to set the input to the 3V level range Set AMPTD to 3V and FREQ to 100 Hz Set the INPUT and OUTPUT switches both to ground If the Source impedance is not already set to 6000 key in 47 0 SPCL to set impedance to 600 1 2 Connect the HIGH OUTPUT to the HIGH INPUT Press RATIO 3 Insert the 6000 feedthrough termination between the HIGH OUTPUT and the HIGH INPUT The right display should read between 49 90 and 50 40 Accuracy of 6000 Output Impedance 49 90 50 40 4 Replace the 6002 feedthrough termination with a 500 feedthrough termination Key in 47 1 SPCL to set the Source impedance to 500 The right display should read between 49 00 and 51 00 Accuracy of 500 Output Impedance 49 00 51 0096 5 Replace the feedthrough termination by a 100 resistor in series with the HIGH INPUT The right display should read between 49 00 and 51 00 Accuracy of High Input Impedance 49 00 51 00 6 Set the INPUT switch to FLOAT Move the connection at the HIGH INPUT to the LOW INPUT The right display shoul
109. UTO Meas CLEAR Automatic selection 300V range 189V range 119V range 75 4V range 47 6V range 30 0V range 18 9V range 11 9V range 7 54V range 4 76V range 3 00V range 1 89V range 1 19V range 0 754V range 0 476V range 0 300V range 0 189V range 0 119V range 0 0754V range Input Level Range except DC level lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt 2zZ LLL Input Level Automatic selection N Range DC 300V range Y Y Level only 64V range Y Y 16V range Y Y 4V range Y Y Post Notch Automatic selection N Gain 0 dB gain Y Y 20 dB gain Y Y 40 dB gain Y Y 60 dB gain Y Y Automatic selection DDDD range DDD D range DD DD range D DDD range 0 DDDD range DD DD mV range D DDD mV range 0 DDDD mV range Hold Decimal Point right display only lt lt lt lt lt lt lt x lt Z lt lt lt lt lt lt lt lt lt ZZZZZZZZ No Not Applicable Y Yes Except the LCL S Shift and Numeric Keys 1 Decimal Point not displayed Leading zero not displayed Shown here in table to clarify decimal point position 3 124 Special Functions 8908 Operation Special Function Summary 2 of 4 Special Function HP IB Lights Code Description SPCL AUTO OP Any Meas CLEAR Post Notch Fa
110. When the SPCL key is pressed the display returns to show the input signal frequency Unless Special Function code 1 0 was entered the light within the SPCL key will turn on if not already on If the light is already on it will remain on COMMENTS When the Audio Analyzer is first powered up or when AUTOMATIC OPERATION is selected the input level range is placed in the automatic selection mode If the input level range is set such that the input signal level creates an overrange condition an error message will be displayed The error message generated depends on instrument settings and the input signal level For example if the input level range is set such that the input signal level causes the input overload detector to trip Error 30 will be displayed For a complete listing of the error messages refer to Error Message Summary Manually selecting the gain of the input level circuitry can cause measurement error Measurement accuracy is not specified whenever the gain of the input level circuitry is manually selected because the selected gain setting may be less than optimum It is important to note that error messages indicating invalid measurements due to incorrect gain settings are not generated unless overload conditions occur Automatic operation ensures accurate measurements for all combination of input signals and measurement modes RELATED SECTIONS AC Level Automatic Operation Input Level Range DC Level Monitor Special Func
111. When used in conjunction with the sweep mode any of the measurement results can be plotted as a function of frequency by connecting an X Y recorder to the Audio Analyzer recorder outputs The recorder outputs are X AXIS Y AXIS and PEN LIFT These outputs are located on the rear panel of the instrument The X AXIS and Y AXIS outputs provide a voltage staircase scaled between 0 and 10 Vdc The output impedance for both outputs is 10000 X axis scaling is determined by the programmed start and stop frequencies The output voltage is proportional to the logarithm of the source frequency as it sweeps The output voltage ranges from 0 Vdc for the start frequency to approximately 10 Vdc for the stop frequency Y axis scaling is determined by the measurement unit selected and the programmed upper and lower plot limits The output voltage is proportional to the displayed reading The output voltage ranges from 0 Vdc for the lower plot limit value to approximately 10 Vdc for the upper plot limit value The PEN LIFT output is a TTL high level for a pen up condition and a T TL low level for a pen down condition During a sweep the PEN LIFT output goes low pen down condition after reaching the first point then goes high again after plotting the last point PROCEDURE The following procedure describes how to use the Audio Analyzer with an X Y recorder 1 The figure below illustrates a typical set up for X Y recording Connect the equipment as shown in the fig
112. a Set all filters off Set RATIO off b Set RATIO on Select the appropriate weighting filter The displayed ratio should be within the limits indicated Table for CCITT Weighting Filter Option 011 or 051 rev 15SEP88 Performance Test 6 4 23 SOURCE Frequency Hz Performance Tests Model 8903B Table for CCIR Weighting Filter Option 012 or 052 31 9 SOURCE Frequency Hz 4 24 Performance Test 6 rev 10AUG88 Model 8903B Performance Tests Table for Message Weighting Filter Option 013 or 053 SOURCE Frequency Hz Performance Test 6 4 25 Performance Tests Model 8903B Table for CCIR ARM Weighting Filter Option 014 or 054 Frequency Hz 4 26 Performance Test 6 rev 10AUG88 Model 8903B rev 10AUG88 Table for A Weighting Filter Option 015 or 055 SOURCE Frequency Hz Ratio Limits dB d Performance Tests Performance Test 6 4 27 Performance Tests Model 8903B Performance Test 7 INPUT AND OUTPUT IMPEDANCE PERFORMANCE TEST Specification Characteristic Performance Limits CeMiions SOURCE OUTPUT LEVEL Impedance 6002 1 or 500 2 MEASUREMENT input Impedance 100kQ 1 Except dc level mode Description The Audio Analyzer s source is connected to its input and a ratio reference set known impedance is then added in parallel to or series with the input
113. a slow decay time constant which captures impulses or other signals with a high crest factor noise or repetitive signal bursts Counter The Counter is a reciprocal counter To measure frequency it counts the period of one or more cycles of the signal at its input then the Controller divides the number of periods by the accumulated count The reference for the Counter is the 2 MHz Time Base which also is the clock for the Controller The Counter has four inputs and three modes of operation Voltage Measurement The time interval from the Voltage to Time Converter is counted The accumulated count is proportional to the dc voltage For direct measurements ac level dc level and distortion level the count is processed directly by the Controller and displayed on the right display For ratio measurements SINAD distortion and signal to noise the counts of two successive measurements are processed and displayed For SINAD and distortion the ratio of the output of the Input RMS Average Detector and Output RMS Average Quasi Peak Detector is computed For signal to noise the ratio of two consecutive outputs from the Output RMS Average Quasi peak Detector is computed One output is with the Oscillator on the other is with the Oscillator off Input Frequency Measurement The signal from the last Programmable Gain Amplifier or the HP BP Filters is conditioned by the Counter Input Schmitt Trigger to make it compatible with the Counter s input Th
114. ain 3 3 SPCL 60 dB gain 3 4 SPCL EXAMPLE To set the post notch gain to 40 dB Code Function LOCAL SPCL keystrokes ee 3 B x 3 3SP program codes codes PROGRAM CODE m For HP IB codes refer to Procedure above INDICATIONS As the numeric code is entered it will appear on the left display When the SPCL key is pressed the display returns to show the input signal frequency Unless Special Function code 3 0 was entered the light within the SPCL key will turn on if not already on If the light is already on it will remain on COMMENTS When the Audio Analyzer is first powered up or when AUTOMATIC OPERATION is selected the Audio Analyzer is placed in the automatic selection mode If the post notch gain is set such that the input signal level causes the post notch circuitry to be overdriven four dashes will be displayed on the right display If this overload condition is not corrected within nine measurement cycles Error 31 will be displayed 3 102 Post Notch Gain Model 8903B Operation Manually selecting the gain of the post notch circuit can cause measurement error Measurement accuracy is not specified whenever the gain of the post notch circuitry is manually selected because the selected gain setting may be less than optimum It is important to note that error messages indicating invalid measurements due to incorrect gain settings are not generated unless overload con
115. al point 3 38 rev 15FEB89 Model 8903B m Operation 3 8 Audio Analyzer Special Function to HP IB Code Summary 1 of 2 Input Level Range except DC Level Automatic Selection 300V range 189V range 119V range 7 54V range 47 6V range 30 0V range 18 9V range 11 9V range 7 54V range 4 76V range 3 00V range 1 89V range 1 19V range 0 754V range 0 476V range 0 300V range 0 189V range 0 119VV range 0 0754V range Input Level Range DC Level only Automatic Selection 300V range 64V range 16V range 4V range Post Notch Gain Automatic Selection 0 dB gain 20 dB gain 40 dB gain 60 dB gain Hold Decimal Point Automatic Selection DDDD range DDD D range DD DD range D DDD range 0 DDDD range DD DD mV range D DDD mV range 0 0000 mV range Special Function Program Code Special Function Program Code Notch Tune Automatic notch tuning Hold notch tuning SINAD Meter Range 0 to 18 dB range 0 to 24 dB range Error Disable All errors enabled Disabled Analyzers errors Errors 12 17 31 and 96 Disable source errors Errors 18 and 19 Disable both Analyzer and Source errors Hold Settings Hold input level ranges post notch gain decimal point and notch tuning at present settings Display Source Settings Display source settings as entered Frequency in left display amplitude in right display Re enter Ratio Mode Restore last RATIO reference and enter RATIO mode if allowe
116. allouts in the test setup diagrams where included If substitutions must be made for the specified test equipment refer to Table 1 3 in Section 1 of this manual for the minimum specifications It is important that the test equipment meet the critical specifications listed in the table if the Audio Analyzer is to meet its performance requirements 5 4 FACTORY SELECTED COMPONENTS Factory selected components are identified on the schematics and parts list by an asterisk which follows the reference designator The normal value or range of the components is shown Manual Update addition and replacement pages provide updated information pertaining to the selected components Table 5 1 lists the reference designator the criteria used for selecting a particular value the normal value range and the service sheet where the component part is shown 5 1 Adjustments Model 8903B Table 5 1 Factory Selected Components Reference Service Range of Basis of Selection Designator Sheet Values A2C4 1 43 to 56 pF See Input Flatness Adjustment A2C9 and A2C102 6 2to 7 5 pF See Input Flatness Adjustment A4R143 andA4R144 147 to infinity See Voltmeter Adjustment A6C26 0 to 25pF See Oscillator and Output Attenuator Attenuator Adjustment A7R8 7 32 to 7 68 If the voltage at the Y AXIS output is gt 10 3 Vdc at full scaled increase the value of the A7R8 if the voltage is lt 9 7 Vdc reduce the value 7 32 to 7 68 If the voltage at
117. ally 11V 10V common mode signal the 1V differential signal A voltage signal this large can exceed the input amplifier s operating range and cause erroneous measurements However the instrument will not be damaged because the Over Voltage Protection circuitry will open whenever the combined common mode and differential signals exceed the instrument s safe operating range Selecting Special Function 1 8 will set the input range to 11 9V Common Mode 3 47 Operation Model 8903B COMMENTS 3 48 For error free measurements the Operating Region For Valid Measurement graphs shown below indicate the maximum allowable common mode input voltages for a given differential input voltage Case 1 is for a single ended source with a common mode signal present on both input lines Case 2 is for a balanced source with common mode signals on both input lines To obtain the maximum common mode input voltage level from the graphs select the desired value for the differential input voltage Then read the common mode input voltage level For example on the Case 1 graph for a differential input voltage level of 1V the maximum common mode input voltage level is 2 8V For a differential input voltage of 60V the maximum common mode input voltage level is 60V VHIGH TO 8903 INPUT VLOW 8 OPERATING REGION FOR VALID MEASUREMENTS INSTRUMENT IN AUTOMATIC OPERATION COMMON MODE INPUT VOLTAGE E ES ii 10 20mV 50mV
118. alyzer is already plugged in set the LINE switch to ON If the power cable is not plugged in follow these instructions 1 Check that the line voltage setting matches the power source see Figure 2 1 2 Check that the fuse rating is appropriate for the line voltage used see Figure 2 1 Fuse Ratings are given under Operator s Maintenance 3 Plug in the power cable 4 Set the LINE switch to ON NOTE When the LINE switch is set to ON all front panel indicators will light for approximately 4 seconds after which the instrument is ready to be operated Local Operation 3 2 Information covering front panel operation of the Audio Analyzer is given in the sections described below rapidly learn the operation of the instrument begin with Simplified Operation and Operator s Checks Once familiar with the general operation of the instrument use the Detailed Operating Instructions for in depth and complete information on operating the Audio Analyzer Simplified Operation Simplified Operation provides a quick introduction to front panel operation of the Audio Analyzer It is designed to rapidly orient the new user with basic procedures and therefore is not an exhaustive listing of all Audio Analyzer functions However an index to the Detailed Operating Instructions appears in Table 3 2 to guide the operator to the more complete discussion of the topic of interest Panel Features Front panel controls indicators and connectors are
119. and ground is minimum when measured by the internal ac voltmeter Equipment Digital Voltmeter sse buch eee sue uan epa HP 3455A Procedure 1 On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Set the INPUT and OUTPUT switches both to ground Connect the voltmeter to the OUTPUT connector on the Audio Analyzer Adjust A6R32 R32 for 0 0 1 mVdc as read on the voltmeter See Service Sheet 10 Set the voltmeter to read ac volts On the Audio Analyzer set AMPTD to 6V Adjust A5R102 OUTPUT LEVEL for an output level of 6 Vrms displayed on the voltmeter 6 On the Audio Analyzer set FREQ to 100 kHz AMPTD to 50 mV and LP FILTER off Set the OUTPUT switch to FLOAT Disconnect the ac voltmeter from the HIGH OUTPUT connector Connect the LOW OUTPUT to the HIGH INPUT 7 Adjust A6C25 not labeled so that the plates go from fully meshed to fully open The right display on the Audio Analyzer should go through a minimum Adjust A6C25 for the minimum display If the adjustment does not go through a minimum change A6C26 to 20 pF if the lowest reading occurs with the plates of A6C25 fully meshed or remove A6C26 if the lowest reading occurs with the plates fully open Then readjust A6C25 See Service Sheet 11 A co N 5 16 Adjustment 9 REGIONAL SALES AND SERVICE OFFICES NORTH CENTRAL AFRICA Hewlett Packard S A 7 rue du Bois du Lan CH 1217 MEYRIN 1 Switzerland Tel
120. ange log 30 000 50 sweep range 2 78 decades 2 Compute the total number of points in a sweep using the formula total number of points points decade x sweep range Since the number of points in a sweep is always an integer round off the result from the above equation to the nearest integer For this example total number of points 5 points decade x 2 78 decades total number of points 13 89 points Therefore the total number of points equals 14 points 3 Compute the frequency points using the frequency point formula Use the result from step 2 to calculate the point numbers Start from n 0 start frequency and continue to n last point stop frequency Note that the stop frequency always equals the programmed stop frequency which can differ from the computed value 3 134 Sweep Resolution Model 8908 Operation For this example the frequency points are computed and listed in the table below Point Number Computed Frequency Point Number Computed Frequency n f 50 Hz 10 5 n f 50 Hz x 10 5 0 50 000 Hz 1990 5 Hz 1 79 245 Hz 3154 8 Hz 2 125 59 Hz 5000 0 Hz 3 199 05 Hz 7924 5 Hz 4 315 48 Hz 12 559 kHz 5 500 00 Hz 19 905 kHz 6 792 45 Hz 31 548 kHz 7 1255 9 Hz For the last point in the sweep the instrument tunes to the programmed stop frequency 30 kHz and not the computed value 31 548 kHz RELATED SECTIONS Special Functions Sweep X Y Reco
121. arizes the major operating characteristics of the Audio Analyzer The table is not intended to be an in depth listing of all operations and ranges but gives an idea of the instrument s capabilities For more information on the Audio Analyzer capabilities refer to the description in Section 1 Table 1 1 Specifications and Table 1 2 Supplemental Information For information on HP IB capabilities refer to the summary contained in Table 3 3 Message Reference Tabie Turn On Procedure Before the Audio Analyzer is switched on all protective earth terminals extension cords auto transformers and devices connected to it should be connected to a protective earth socket Any interruption of the protective earth grounding will cause a potential shock hazard that could result in personal injury In addition verify that a common ground exists between the unit under test and the Audio Analyzer prior to energizing either For continued protection against fire hazard replace the line fuse with a 250V fast blow fuse of the same rating Do not use repaired fuses or short circuited fuseholders CAUTION Before the Audio Analyzer is switched on it must be set to the voltage of the power source or damage to the instrument may result Do not allow the voltage at the SOURCE OUTPUT HIGH or LOW terminal to be greater than 10V or less than 10V ac dc or damage to the instrument may result 3 1 Operation Model 8903B If the Audio An
122. asurements press z Scc sa 5 LEVEL LEVEL FILTERS HP BP Filter CORRESPONDING To activate any of the optional plug in filters press gt LOW PASS 30 kHz LP Filter To activate the LOW PASS 30 kHz filter press 3 8 Model 8903B Model 8903B Operation SWEEP Start Frequency To set the start frequency of the sweep to 100 Hz es 88 C C 3D Stop Frequency To set the stop frequency of the sweep to 10 kHz press 1 Starting the Sweep To start the frequency sweep press RATIO and LOG LIN RATIO To set the displayed measurement as the ratio reference press e RATIO LOG LIN To convert from linear to logarithmic or from logarithmic to linear measurement units press an Measurement RATIO on RATIO off te Mode AC LEVEL DC LEVEL SINAD SIG NOISE DISTN DISTN LEVEL dBm into 6009 dBm into 6002 ENCEN dB dB dB dB dB dB dBm into 600Q NOTE During power up the Audio Analyzer is initialized and set to AUTOMATIC OPERATION NOTE Some delays may be noted when pressing keys during sweeps with an x y recorder enabled These delays allow the pen to lift before moving However the keys are recognized and it is unnecessary to hold them down while waiting for the Audio Analyzer to respond 3 9 8908 Table 3 2 Detailed Operating Instruction Table of Contents functional Listing Operation Sec
123. at the notch filter is coarsely programmed to the frequency of the internal source but fine tuned to the signal at its input This permits measurements in the presence of large amounts of impurities and assures that the fundamental is tuned out If an external source is used it must be within 596 of the frequency setting of the internal source SINAD is an acronym for SIgnal Noise And Distortion The ratio normally expressed in dB computed in the SINAD measurement is SINAD 20 log 69 rms value nose and distortion The equation eliminates the two restrictions discussed in connection with the distortion measurement SINAD is used most often in determining the sensitivity of a receiver Receiver sensitivity is defined as the RF level that when modulated in a specified manner with a pure audio tone creates a certain SINAD usually 10 or 12 dB at the receiver s audio output The tone can just be discerned in the noise Sometimes a psophometric that is noise measuring filter is required in the receiver sensitivity measurement Optional plug in weighting filters modify the frequency response of the Audio Analyzer with a bandpass characteristic that approximates the response of human hearing Weighting filters which meet most international standards are available Signal to Noise Ratio Measurement of the signal to noise ratio requires the use of the Audio Analyzer s internal source The Audio Analyzer simply turns the source
124. ation on each plug in filter option can be found in the Detailed Operating Instructions in Section 3 under Filters Mechanical Options The following options may have been ordered and received with the Audio Analyzer If they were not ordered with the original shipment and are now desired they can be ordered from the nearest Hewlett Packard office using the part number included in each of the following paragraphs The mechanical options are shown in Figure 1 4 Front Handle Kit Option 907 Ease of handling is increased with the front panel handles Order HP part number 5061 9689 Rack Flange Kit Option 908 The Audio Analyzer can be solidly mounted to an instrument rack using the flange kit Order HP part number 5061 9677 Rack Flange and Front Handle Combination Kit Option 909 This is not a front handle kit and a rack flange kit packaged together it is composed of a unique part which combines both functions Order HP part number 5061 9683 1 6 8908 General Information SPARE INTERNAL FUSES eeepc MAR ATI LEA NN LINS S V SANNAA A OX SS AN ANN S SN gt OPTION 909 OPTION 907 RACK FLANGE AND FRONT FRONT HANDLE KIT HANDLE COMBINATION KIT OPTION 908 RACK FLANGE KIT NOTE Refer to ACCESSORIES SUPPLIED for more details Figure 1 4 HP 8903B Accessories Supplied and Options 907 908 and 909 ae Se _ _ General Information Model 8903B 1 8
125. board entry using the SPCL key The following discussion describes this function for all measurement modes except DC Level mode Refer to Input Level Range DC Level for additional information The input circuitry consists of a programmable attenuator and two programmable amplifiers In automatic operation mode the gain of the attenuator amplifier section of the input is automatically set according to the level of the input signal PROCEDURE To set the input level range to a selected range or to re enter the automatic selection mode key in the corresponding Special Function Code then press the SPCL key Program Code input Teva Fange Specia Function Code y Full Scale m Automatic Selection 1 0 SPCL 300V 1 1 SPCL 189V 1 2 SPCL 119V 1 3 SPCL 75 4V 1 4 SPCL 47 6V 1 5 SPCL 30 0V 1 6 SPCL 18 9V 1 7 SPCL 11 9V 1 8 SPCL 7 54V 1 9 SPCL 4 76V 1 10 SPCL 3 00V 1 11 SPCL 1 89V 1 12 SPCL 1 19V 1 13 SPCL 0 754V 1 14 SPCL 0 476V 1 15 SPCL 0 300V 1 16 SPCL 0 189V 1 17 SPCL 0 119V 1 18 SPCL 0 0754V 1 19 SPCL EXAMPLE To set the input level range to the 30 0V range 7 Code Function LOCAL SPCL keystrokes 6 x 1 6SP pones Function program codes 3 88 Input Level Range Except DC Level Model 8903B Operation PROGRAM CODE x For HB IB codes refer to Procedure above INDICATIONS the numeric code is entered it will appear on the left display
126. bus control line true if an Service invalid program code is received The Audio Analyzer will also set SRQ true if enabled by the operator to do so when measurement data is ready or when an instrument error occurs Status Byte 1 removing the causing condition and 2 reading the Status Byte Status Bit The Audio Analyzer does not respond to a parallel pol The Audio Analyzer does not respond to a parallel poll The Audio Analyzer does not respond to a pae pol PPO The Audio Analyzer stops talking and listening ae T5 L3 LEO Commands Control lines and Interface Functions are defined in IEEE Std 488 Knowledge of these might not be necessary if your controller s manual describes programming in terms of the twelve HP IB Messages shown in the ieft column Related Commands Interface and Functions Controls l The Audio Analyzer responds to Serial Poll Enable SPE bus command by sending an 8 bit byte when addressed to talk If the instrument is holding the SRQ control line true issuing the Require Service message bit 7 RQS bit in the Status Byte and the bit representing the condition causing the Require Service message to be issued will both be true The bits in the Status Byte are latched but can be cleared by Complete HP IB capability as defined in IEEE Std 488 and ANSI Std MC1 1 is SH1 5 TEO L3 LEO SR1 RL1 DC1 DTI
127. by the controller using the Local or Clear Lockout Set Local messages by setting the LINE switch to OFF and back to ON or by removing the bus cable Receiving the Clear Lockout Set Local Message The Clear Lockout Set Local message is the means by which the controller sets the Remote Enable REN bus control line false The Audio Analyzer returns to local mode full front panel control when it receives the Clear Lockout Set Local message No instrument settings are changed by the transition from remote with local lockout to local When the Audio Analyzer goes to local mode the front panel REMOTE annunciator turns off Receiving the Pass Control Message The Audio Analyzer does not respond to the Pass Control message because it cannot act as a controller Sending the Require Service Message The Audio Analyzer sends the Require Service message by setting the Service Request SRQ bus control line true The instrument can send the Require Service message in either local or remote mode The Require Service message is cleared when a serial poll is executed by the controller or if a Clear message is received by the Audio Analyzer During serial poll the Require Service message is cleared immediately before the Audio Analyzer places the Status Byte message on the bus An HP IB code error will always cause a Require Service message to be issued In addition there are two other conditions which can be enabled to cause the Require Service message to
128. c or dc Impedance 100 kQ except dc level 101 KQ dc level floating input can be selected Input Limits AC Level 0 to 300 Vac 20 Hz to 150 kHz Full range display from 3000 mV to 300 0V in seven ranges Measurements including counter frequency measurements except in DC Level DC Level 0 to 300 Vdc Full range display from 4 000V to 300 0V in four ranges Sinad 50 mV to 300V 20 Hz to 100 kHz Display range 0 to 99 99 dB SINAD meter marked for EIA and CEPT readings SIG NOISE 50 mV to 300V 50 Hz to 100 kHz Display range O to 99 99 dB DISTN 50 mV to 300V 20 Hz to 100 kHz Display range 99 99 to 0 dB DISTN LEVEL Similar to ac level except that the notch filter is used in the measurement True rms average detection or Quasi Peak output Detector only Swept All measurements can be swept and frequency vs measurement result Measurements can be plotted using an external X Y recorder HP BP Filter Up to two of the following HP BP filters may be installed HIGH PASS 400 Hz 400 40 Hz 3 dB cutoff CCITT Weighting CCITT Recommendation P53 CCIR Weighting CCIR 468 2 C MESSAGE BSTM 41009 FIG 1 A Weighting ANSI 1 4 IEC rec 179 CCIR ARM Weighting CCIR 468 2 Dolby Labs LP FILTER Low PASS 30 kHz 302 2 kHz 3 dB cutoff 80 kHz 80 4 kHz 3 dB cutoff Audio Filters Output level and frequency input attenuation ratio log linear disp
129. c sensitive devices should attempt to service circuitry with these devices In all instances measures must be taken to prevent static charge build up on work surfaces and persons handling the devices For further information on ESD precautions refer to SPECIAL HANDLING CONSIDERATIONS FOR STATIC SENSITIVE DEVICES in Section VIII Service Section Safety Considerations HP 8903B Table of Contents TABLE OF CONTENTS Section 1 General Information Introduction ob aw co die 1 1 SDECINCALIONS CM CC v 1 1 Safety Considerations 1 2 Instruments Covered By Manual 1 2 Manual Changes s ace sob Re RN UR ac dp dese dei cbs aloe ees 1 2 poi M feces nach top By En XC 1 8 t prt 1 3 Adio rM 1 3 Transc iver Testing creed eG CER ue eeu tes ce 1 4 S poo ru 1 5 Sho e M eae face tic ea sa aise cu 1 6 Electrical Options SD ve ve Bok ete Dx 1 6 Mechanical Options 1 6 Hewlett Packard Interface Bus 1 8 Compatibili EMPTUM 1 8 Selecting the HP IB 5 1 8 Accessories Suppli
130. cally equivalent to a front panel keystroke in local mode Thus for a given operation the program string syntax in remote mode is the same as the keystroke sequence in local mode For information about RS Rapid Source refer to Rapid Source in the Detailed Operating Instructions Example 1 shows the general case programming order for selecting Audio Analyzer functions Specific program order considerations are discussed in the following paragraphs under Program Order Considerations All functions can be programmed together as a continuous string as typified in Example 2 The string in Example 2 clears most Special Functions with Automatic Operation programs the source to 440 Hz at 1V selects a distortion measurement with 30 kHz low pass filtering and log units then triggers a settled measurement Program Codes Most all of the valid HP IB codes for controlling Audio Analyzer functions are summarized in Table 3 6 All front panel keys except the LCL key and the 10 and x10 keys have corresponding program codes exception Service Special Functions Table 3 4 shows the Audio Analyzer s response to various ASCII characters not used in its code set The characters in the top column will be ignored unless they appear between two characters of a program code The characters in the bottom column if received by the Audio Analyzer will always cause Error 24 invalid HP IB code to be displayed and a Require Service message to be generated The
131. ce directly to the Audio Analyzer to make measurements Transceiver Testing The Audio Analyzer has several measurements and features specifically designed for transceiver testing It has SINAD and signal to noise ratio measurements for receiver testing optional internal plug in weighting filters for testing to international standards a reciprocal counter for measuring squelch tones and an optional internal plug in 400 Hz high pass filter for eliminating squelch tones when measuring transmitter audio distortion SINAD is one of the most basic receiver measurements It must be made repeatedly when performing sensitivity or adjacent channel sensitivity tests In the Audio Analyzer the SINAD measurement is more heavily filtered than the distortion measurement in order to smooth the noisy signals encountered in receiver testing The filtering is optimized for excellent repeatability and speed 2 readings second typical Some automatic distortion analyzers have a tendency to become untuned when measuring SINAD on noisy signals The Audio Analyzer overcomes this problem by tuning the notch filter to Model 8903B General Information the source frequency when measuring SINAD SINAD measurement results are indicated both by the digital display and a front panel analog meter The meter is specifically marked for and sensitivity and selectivity For SINAD ratios less than 25 dB the digital display is automatically rounded to the nearest
132. ce Special Function is performed Automatic operation does not clear a Require Service message PROCEDURE To enable one or more conditions to cause the Audio Analyzer to issue a Require Service message sum the weights of the conditions to be enabled from the table below This sum becomes the code suffix of Special Function 22 Enter the Special Function code prefix decimal and suffix via the numeric keyboard then press the SPCL key An HP IB code error weight 2 will always cause a Require Service message This condition cannot be disabled and if the weight is not summed in it will be assumed by the instrument Data ready HP IB code error Instrument error EXAMPLE To set the Audio Analyzer to send a Require Service message when an instrument error occurs or when an HP IB code error occurs first compute the Special Function suffix by summing the weights corresponding to those conditions 2 4 6 Then enter the code s Code Function LOCAL SPCL keystrokes 2 2 G g ez uar program codes Code Function 3 116 Service Request Condition Model 8903B Operation PROGRAM CODES a gt Compute the Special Function code as described under Procedure above SP is the HP IB code for the SPCL key INDICATIONS As the numeric code is enter ed it will appear on the front panel display When the SPCL key is pressed the display returns to show the measurement previously selected
133. ceiving the Abort message Status Byte Message Description This check determines whether or not the Audio Analyzer sends the Status Byte message in both the local and remote modes This check assumes that the Audio Analyzer is able to handshake recognize its own address and make the remote local changes Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON Place the Audio analyzer in serial poll mode and rds 728 V Series 80 Controllers address it to talk causing it to send the Status Byte STATUS 728 V message Series 200 300 controllers Define V with rds 728 Series 200 300 Controllers the program instruction V SPOLL 728 10V 0 20 END Display the Value of V PRINT V Check that Audio Analyzer s REMOTE annunciator is off Depending upon the vintage of the HP IB interface HP HPL used the Audio Analyzer s ADDRESSED annunciator may be either on or off The controller s display should read 0 00 HPL or 0 BASIC 3220 rev O8A LIGIO Model 8903B Operation Send the Remote message rem 728 REMOTE 728 Series 80 Controllers STATUS 728 V Series 200 300 Controllers V SPOLL 728 PRINT V Place the Audio Analyzer in serial poll mode and address it to talk causing it to send the Status Byte message rds 728 V Display the value of V dsp V Check that the Audio Analyzer s REMOTE annunciator is on Depending upon th
134. ch converts the measurement result into watts for a specified external load resistance Another important ac signal characteristic is the variation in level vs frequency flatness Of course you can easily set a reference level such as 1V at a particular frequency such as 1 kHz and monitor the change in level as the input frequency is changed The source s level is assumed to be flat otherwise it too must be checked The Audio Analyzer makes this measurement easier in three ways First the analyzer contains a flat wide range oscillator that can be used as the stimulus Second the reference can be set to 10096 or 0 dB by the press of a button the RATIO key Third the measurement can be automatically swept and the results can be plotted by connecting an x y recorder to the rear panel X AXIS and Y AXIS outputs An additional parameter related to ac level is gain and more often gain vs frequency To make a gain measurement measure the input to the device then the output and take the ratio This measurement is made easier by the Audio Analyzer when used with its internal oscillator You first key in the desired input level then either measure it and set it as a reference press RATIO or key in the level as the ratio reference Then measure the output The result can be expressed in either or dB If desired the input can be swept and the gain plotted as a function of frequency since the frequency plots logarithmically the result i
135. cial internal measurements software control and special service tests and configurations Most instrument safeguards are relinquished These Special Functions are discussed in detail in Section 8 If a Service Special Function is entered inadvertently press AUTOMATIC OPERATION Viewing Special Function States In addition to completing the entry of Special Function codes the SPCL key allows viewing of some Special Function settings The operator requested settings of Special Functions prefixed 1 through 8 may be viewed by pressing the SPCL key once following no numeric entry This display is called the Special Display If some of these Special Functions are in automatic modes generally the 0 suffix setting the actual instrument settings of these functions may be displayed by pressing the SPCL key a second time while the Special Display is active This display is called the Special Special Display If desired these displays can be cleared by pressing any key except the LCL numeric or S Shift keys While either display is active pressing the SPCL key will switch to the other display summary of User Special Functions is given on the following pages Following the summary are procedures for using Special Display These displays are also illustrated and explained Special Functions 3 123 Model 8903B Special Function Summary 1 of 4 Special Function HP IB Lights Code SPCL A
136. cillator is used it must be tuned to within 5 of the internal oscillator frequency If it is not the notch filter will not tune to the fundamental frequency of the input signal PROCEDURE First manually set the internal oscillator to the frequency desired To do this press FREQ enter the numeric value for the desired frequency and then press the appropriate unit key for example kHz Next press SINAD If the internal source is being used as a stimulus also key in the desired amplitude for the modulation signal The SINAD ratio can then be read on the right display or the SINAD meter if within range Special Function 7 can be used to change the SINAD meter range EXAMPLE set the internal source to 1 kHz and select SINAD 4 Data Unit Measurement LOCAL keystrokes G CE mE aa unction easuremen program codes Data Unit PROGRAM CODE m M2 is the HP IB code for the SINAD measurement 3 120 SINAD Model 8908 Operation INDICATIONS When either the FREQ or AMPTD key is pressed the currently programmed values are displayed in the left and right displays respectively When the numeric data is entered the numbers appear in the left display When the unit keys are pressed both displays blank and four dashes are momentarily displayed in the left display The displays then return to the normally displayed information for the currently selected measurement mode When
137. cked four byte output for fast counting Also a rapid source binary programming mode is available which allows the internal oscillator tuning to be programmed directly with five bytes of data 1 5 a General Information Model 8903B 1 7 OPTIONS Electrical Options Electrical Option 001 This option provides rear panel instead of front panel connections for both the INPUT and OUTPUT HIGH and LOW BNC connectors Internal Plug in Filter Options The Audio Analyzer has two plug in filter positions each position can be loaded with any one of six optional filters Each filter is referenced to its corresponding filter position by one of two option numbers For example the 400 Hz high pass filter option can be ordered as Option 010 which corresponds to the left most filter position or as Option 050 which corresponds to the right most filter position These optional plug in filters can be configured in any combination desired If there is no filter ordered for a position a jumper is loaded and a label marked No Filter is placed above the filter key on the front panel The following list includes the name and option numbers for each available filter e 400 Hz High Pass Filter Option 010 050 e CCITT Weighting Filter Option 011 051 e CCIR Weighting Filter Option 012 052 e C MESSAGE Weighting Filter Option 013 053 e CCIR ARM Weighting Filter Option 014 054 e Weighting Filter Option 015 055 Specific inform
138. controller recognizes the invalid code entry and clears the Require Service condition Thereafter the invalid code entry is ignored and subsequent valid entries are processed in normal fashion As a convenience all lower case alpha characters are treated as upper case Model 8903B mm Operation Table 3 4 Audio Analyzer Response to Unused ASCII Codes Except when inserted between two characters of a pro gram code EXAMPLE 1 General Program Syntax and Protocol Controller Talk Audio Analyzer Listen Automatic Operation Source Frequency Source Amplitude Measurement Filters Special Functions Log Lin Ratio Start Frequency Stop Frequency Plot Limit Sweep Trigger Excluding Rapid Source or Rapid Frequency Count Modes EXAMPLE 2 Typical Program String Controller Talk Audio Analyzer Listen FR440HZAP1VLM3L 1 TT Automatic owe be With Settling Source eer Source Amplitude 30 aa Low Pass Filter Distortion Turning off Functions When operating in local mode the High Pass Bandpass optional plug in filters and Low Pass Filters and Ratio functions toggle on and off with successive keystrokes In remote mode these functions do not toggle on and off Instead each of the above groups has a specific code which turns off all the keys in the group The HP IB codes for turning off these functions are given in the following table HP BP FILTERS off LP F
139. crement DESCRIPTION The frequency and amplitude of the source can be incremented or decremented using the proper combination of the FREQ FREQ INCR AMPTD AMPTD INCR 10 x10 and FREQ AMPTD ADJUST keys These keys provide a convenient method of controlling the source when it is used in applications such as locating the 3 dB point of filters and amplifiers PROCEDURE The general procedure to change the source parameters is to use either the FREQ INCR or AMPTD INCR key to establish which parameter is to be changed and the initial increment size The FREQ AMPTD ADJUST keys are then used to modify the source output EXAMPLES To set the amplitude increment to 1 5V Function Data Unit LOCAL keystrokes 1 5 C program codes Function To increment the currently programmed source amplitude value 1 5 LOCAL Function keystrokes 4 UP gt program codes Function To divide the currently programmed amplitude increment by 10 that is to set the amplitude increment to 0 15V Function LOCAL keystrokes lt gt program codes This function is not programmable Increment 3 83 Operation Model 8903B NOTE In the last two examples above either the programmed amplitude or amplitude increment would be changed only if either the AMPTD or AMPTD INCR key was pressed last If either the FREQ or FREQ INCR key
140. d Display RATIO reference Signal to Noise Measurements Delay Automatic Selection 200 ms delay 400 ms delay 600 ms delay 800 ms delay 1 0s delay 1 2s delay 1 4s delay 1 6s delay 1 8s delay X Y Recorder Enable plot Disable plot 3 39 Operation lt 2 Model 8903B Table 3 8 Audio Analyzer Special Function to HP IB Code Summary 2 of 2 Program Code Special Function Program Code Time Between Measurements Minimum time between measurements Add 1s between measurements Post Notch Detector Response except in SINAD Fast RMS Detector Slow RMS Detector Fast AVG Detector Slow AVG Detector Quasi peak Detector Read Display to HP IB Read right display Read left display SINAD and Signal to Noise Display Resolution 0 01 dB above 25 dB 0 5 dB below 25 dB 0 01 dB all ranges HP IB Address Displays HP IB address in binary in left display right display in form TLS where T 1 means talk only L 1 means listen only S 1 means SRQ Displays HP IB address decimal Sweep Resolution maximum 255 points sweep 10 points decade 17 0SP 1 point decade 17 1SP 2 points decade 17 2SP 5 points decade 17 3SP 10 points decade 17 4SP 20 points decade 17 5SP 50 points decade 17 6SP 100 points decade 17 78P 200 points decade 17 8SP 500 points decade 17 9SP HP IB Service Request Condition Enable a Condition to to cause a service request N is the sum of any combination of of
141. d count bytes using the Binary format Line 30 Calculate T total clock counts by bit manipulation and proper weighting Line 40 Calculate total cycle counts by bit manipulation and proper weighting Line 50 Calculate the frequency F total cycle count total clock count X 2 X 109 Note that the value is multiplied by 100 to round the integer part and then divide by 100 to round the answer to 2 digits to the right of the decimal Line 60 Displays the frequency count result Line 70 Terminates the program Using a HPL controller such as the Hewlett Packard Model 9825A Desktop Controller the computation is set up in seven steps as shown below wrt 728 RF fmt z 4b red 728 ri r2 r3 r4 shf r2 4 16 band r2 15 band r4 28 1024 260 r1 r5 band r4 15 16 255 r3 r6 2e6r6 r5 B dsp B end i WH O Explanation Line 0 Place the Audio Analyzer in the Rapid Frequency Count mode Lines 1 2 Establish a format suitable for reading four binary bytes from the Audio Analyzer Take the readings and store the value in four r variables The value stored is the decimal equivalent of the binary word Line 3 Shift various bytes around and weight their value by the proper amount in accordance with the routine given to obtain the number of Audio Analyzer clock counts Assign that value to variable r5 Line 4 Position bits correctly and w
142. d read between 49 00 and 51 00 Accuracy of Low Input Impedance 49 00 51 00 4 28 Performance Test 7 Model 8903B Performance Tests Performance Test 8 COMMON MODE REJECTION RATIO PERFORMANCE TEST Specification Characteristic Performance Limit Ceiins GENERAL Common Mode Rejection Ratio Differential input 2V 20 to 1000 Hz Differential input 22V 20 to 1000 Hz 1 to 20 kHz Description The output from the internal source is connected to both the high and low inputs of the Audio Analyzer The low input is set to float The ac level of the common mode input is then measured for two different input ranges HIGH INPUT ga 0 mEos Figure 4 2 Common Mode Rejection Ratio Test Setup Procedure 1 On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Set the OUTPUT switch to ground Set the INPUT switch to FLOAT Key in 47 0 SPCL to set the Source impedance to 6000 Set AMPTD to 1V 2 Connect the HIGH OUTPUT to the HIGH INPUT through the tee as shown in Figure 4 2 3 Key in the Special Function indicated in the table below For each setting the right display should read within the limits indicated Special Oscillator AC Level Limits mV Frequency Performance Test 8 4 29 Performance Tests Model 8903B Table 4 1 Performance Test Record 1 of 12 Hewlett Packard Company Model 89038 Tested by Audio Analyzer Serial Number _ LL
143. d the ac voltmeter readings are the same within the limits stated for both 3V and 150 mV On the Audio Analyzer key in 5 2 SPCL to select the averaging detector Set AMPTD to 3V Adjust A4R93 SCALE for a reading on the right display of the Audio Analyzer that 15 the same as the reading on the ac voltmeter within X1 mV See Service Sheet 6 Set AMPTD to 150 mV Adjust A4R149 AVG OFFSET for a reading on the right display of the Audio Analyzer that is the same as the reading on the ac voltmeter within 0 5 mV See Service Sheet 6 Set AMPTD to 3V Repeat steps 9 through 11 until the right display of the Audio Analyzer and the ac voltmeter are the same within the limits stated for both 3V and 150 mV Key in 5 7 SPCL to select the quasi peak detector Adjust A4R207 QUASI PEAK for a reading on the right display of the Audio Analyzer that is the same as the reading on the ac voltmeter within 1 mV See Service Sheet 6 Adjustment 7 8908 Adjustments Adjustment 8 SINAD METER ADJUSTMENT Reference Service Sheet 6 Description The SINAD meter is mechanically zeroed with the measurement mode not set to SINAD Next a signal from the internal source is fed into the input the measurement mode is set to SINAD and the notch filter allowed to tune to the signal The notch filter is then held and the frequency of the source is offset to mistune the notch filter The mistuning produces a SINAD rea
144. damage This product is designed for use in Installation Category II and Pollution Degree 2 per IEC 1010 and IEC 664 respectively FOR INDOOR USE ONLY This product has autoranging line voltage input be sure the supply voltage is within the specified range Chapter 1 Regulatory Information Updated March 1999 To prevent electrical shock disconnect instrument from mains line before cleaning Use a dry cloth or one slightly dampened with water to clean the external case parts Do not attempt to clean internally Ventilation Requirements When installing the product in a cabinet the convection into and out of the product must not be restricted The ambient temperature outside the cabinet must be less than the maximum operating temperature of the product by 4 C for every 100 watts dissipated in the cabinet If the total power dissipated in the cabinet is greater than 800 watts then forced convection must be used Product Markings CE the CE mark is a registered trademark of the European Community A CE mark accompanied by a year indicated the year the design was proven CSA the CSA mark is a registered trademark of the Canadian Standards Association 4 Chapter 1 CERTIFICATION Hewlett Packard Company certifies that this product met its published specifications at the time of shipment from the factory Hewlett Packard further certifies that its calibration measurements are traceable to the United States National B
145. ding within the range of the SINAD meter The meter is then adjusted to agree with the displayed SINAD Procedure d On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Set the INPUT and OUTPUT switches both to ground Key in 16 1 SPCL to set the SINAD resolution to 0 01 dB Place the instrument in its normal operating position Connect the HIGH OUTPUT to the HIGH INPUT Adjust the mechanical zero adjustment screw on the panel meter cw for a zero meter reading then turn the screw slightly ccw to free the mechanism from the adjusting peg Set AMPTD to 3V and MEASUREMENT to SINAD Key in 7 1 SPCL to enable the 24 dB SINAD meter range Key in 6 1 SPCL to hold the notch filter Set FREQ to 890 Hz Fine adjust the source frequency to obtain a reading on the right display between 12 and 18 dB Adjust A4R142 METER CAL so that the panel meter reads the same as the right display Adjustment 8 5 15 Ss ns es yl Adjustments Model 8903B Adjustment 9 OSCILLATOR AND OUTPUT ATTENUATOR ADJUSTMENT Reference Service Sheets 9 10 and 11 Description With the oscillator turned off the dc offset of the output circuits is adjusted for OV The oscillator is then turned on and adjusted at 1 kHz for 6 Vrms output into an open circuit Finally the oscillator is set to 50 mV at 100 kHz and the high frequency balance of the output amplifier is adjusted so that the voltage between the source s low output
146. dio Analyzer s ADDRESSED annunciator is off Note that the BASIC ABORTIO statement sends both the Abort message and the Local message Thus if HPL is being used the Audio Analyzer s REMOTE annunciator should remain on If BASIC is being used the Audio Analyzer s REMOTE annunciator should turn off Send the Local message ABORTIO 7 HPL only The Local message was already sent with the ABORTIO 7 statement above Address the Audio Analyzer to talk and store its ENTER 728 V output data in variable V Check that the Audio Analyzer s REMOTE annunciator is off but its ADDRESSED annunciator 15 on rev OSAUG90 3 19 Operation Model 8903B Send the Abort message unaddressing the Audio cli 7 ABORTIO 7 Analyzer to talk Check that both the Audio Analyzer s REMOTE and ADDRESSED annunciators are off Send the serial poll enable bus command SPE wti 0 7 wti 6 24 Series 80 Controllers through the interface to place the Audio Analyzer in SENDBUS 728 1 24 serial poll mode Series 200 300 Controllers SEND 7 CMD 1 24 On the Audio Analyzer key in 61 3 SPCL The right display should show 1 0 This indicates the Audio Analyzer is in serial poll mode indicated by the 1 Send the Abort message removing the Audio cli 7 ABORTIO 7 Analyzer from serial poll mode Check that the Audio Analyzer s right display shows 0 0 This indicates the Audio Analyzer properly left serial poll mode upon re
147. ditions occur Automatic operation ensures accurate measurements for all combination of input signals and measurement modes RELATED SECTIONS Automatic Operation Special Functions Monitor Post Notch Gain 3 103 Model 8903B Rapid Frequency Count DESCRIPTION Rapid Frequency Count mode allows a remote controller to partially bypass the Audio Analyzer s own internal controller The advantage is that frequency count measurements can be obtained from the Audio Analyzer much more quickly The data obtained however is in a packed binary form and thus requires additional processing to produce the final results in hertz Once the Rapid Frequency Count mode is entered data will be placed on the bus in four byte sequences until the mode is terminated Rapid Frequency Count mode is terminated whenever the Audio Analyzer receives a bus command or whenever it is sent new programming data PROCEDURE 3 104 To use the Rapid Frequency Count mode the remote controller must be able to read the four byte compacted frequency data using a binary specifier First place the Audio Analyzer into the ac level measurement mode set it to measure the input signal that 1s the signal before the notch filter and to trigger with settling The HP IB codes for this configuration are M146 1SP T8 Next issue the HP IB code for Rapid Frequency Count RF and then read the frequency data from the Audio Analyzer The Audio Analyzer does not s
148. dress wrt 728 OUTPUT 728 Check that the Audio Analyzer s REMOTE annunciator is off but its ADDRESSED annunciator is on Model 8903B EP Operation Unaddress the Audio Analyzer by sending wrt 729 OUTPUT 729 different address Check that both the Audio Analyzer s REMOTE and ADDRESSED annunciators are off Remote and Local Messages and the LCL Key Description This check determines whether the Audio Analyzer properly switches from local to remote control from remote to local control and whether the LCL key returns the instrument to local control This check assumes that the Audio Analyzer is able to both handshake and recognize its own address Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON ENENC HN NC NNNM B Check that both the Audio Analyzer s REMOTE and ADDRESSED annunciators are on Send the Local message to the Audio Analyzer ici 728 LOCAL Check that the Audio Analyzer s REMOTE annunciator is off but its ADDRESSED annunciator is on Send the Remote message to the Audio Analyzer REMOTE 728 Check that both the Audio Analyzer s REMOTE and ADDRESSED annunciators are on Press the LCL key on the Audio Analyzer Check that the Audio Analyzer s REMOTE annunciator is now off but that its ADDRESSED annunciator remains on Send the Remote message by setting Remote Enable REN true and addressing the Audio Analyzer to listen Sending the Data Me
149. e as the source frequency only if the source is the stimulus for the input For an alternate method of programming frequency with high rapidity 3 ms typical see Rapid Source For a method which permits a faster frequency counting over HP IB see Rapid Frequency Count RELATED SECTIONS Amplitude Increment Rapid Frequency Count Rapid Source Frequency 3 75 Operation Model 8903B Hold Decimal Point Special Function 4 DESCRIPTION The position of the decimal point in the right display can be held in a specific position by using Special Function 4 PROCEDURE To hold the decimal point in the right display to a specific position key in the corresponding Special Function code then press the SPCL key Special Program Function Code Code Decimal Hold Position Automatic Selection 4 0 SPCL DDDD V Range 4 1 SPCL DDD D V Range 4 2 SPCL DD DD V Range 4 3 SPCL D DDD V Range 4 4 SPCL 0 DDDD V Range 4 5 SPCL DD DD mV Range 4 6 SPCL D DDD mV Range 4 7 SPCL 0 DDDD mV Range 4 8 SPCL The decimal point does not appear on the display It is shown to establish the position it would appear in the numeric value of the readout The zero does not appear on the display It is shown to clarify the position of the decimal point EXAMPLE To hold the decimal point after the first digit of a mV Range D DDD mV Code fFunction SPCL C B 4 7SP program codes
150. e Audio Analyzer Also included are references to other sections which contain related information The Detailed Operating Instructions are designed so that both casual and sophisticated users can rapidly find at one location all the information needed to apply the instrument to the task at hand SN en Model 8903B Operation Operating Information Pull Out Cards The Operating Information pull out cards are flexible plastic reference sheets attached to the Audio Analyzer by a tray located below the front panel They contain a complete listing of HP IB codes and data and error output formats Error codes and User Special Functions The cards are intended to be a reference for the user who already has a basic understanding of front panel operation Supplemental Information In addition to the information described above several other discussions pertinent to the operating of the Audio Analyzer to its fullest capabilities are contained in Section 1 of this manual Principles of Operation for a Simplified Block Diagram is a fundamental description of what the Audio Analyzer is and how it works This information supplements the block diagrams given in the Detailed Operating Instructions and provides a basis for applying the Audio Analyzer to various measurement situations Basics of Audio Measurements is a general discussion of audio measurements It is intended to provide an intuitive understanding of audio measurements rather than an in depth math
151. e Audio Analyzer the controller must send either an Abort message a new talk address or a universal untalk command Talk Only Mode If the internal address switches are set to a valid Talk address and the TON Talk Only switch is set to 1 the Audio Analyzer is placed in the Talk Only mode In this mode instrument is configured to send Data messages whenever the bus is in the data mode Each time the measurement is completed the measurement result will be output to the bus unless the listening device is not ready for data If the listener is not ready and the Audio Analyzer is not in a trigger mode another measurement cycle is executed Model 8908 xm Operation Talk Status Only Mode If all the internal address switches and the TON Talk Only switch are set to 1 but the LON Listen Only switch is set to 0 the Audio Analyzer is placed in the Talk Status Only mode In this mode the instrument is configured to send a one byte data message whenever the bus is in the data mode The byte sent is an exact copy of the Status Byte Each time this byte is successfully sent on the bus the internal Status Byte is cleared The Data Valid DAV handshake line is pulsed each time the one byte Data message is sent Data Output Format As shown below the output data is usually formatted as a real constant in exponential form first the sign then five digits leading zeros not suppressed followed by the letter E and a signed powe
152. e Request 3 114 Signal to NoE 5 4 24 xo e E IRR Ie NEC Oe as IET EES ow eee ees ee 3 116 Special Funcions c r 3 121 DW COD NS a a a Gate i ne a he ets CP 3 128 SWEEP RESOLTO a e Re CO do SL Ba we an ea ats ee Aga 3 131 Time Between Measurements 3 134 Xy Recordie E 2c d eps 3 135 CETERI RNLCLLICITTST IUIQUOITIVP PTT 4 1 Equipment Required vob Erb Ele e REOR woe i oe ie EL 4 1 jog Tel C rrrrTTM 4 1 Calibration Td Tr PPP aid ce ie ae Bs st Ge Ss Gd de os ok A GR eh re 4 1 Abbreviated Performance 4 1 Performance Test 1 AC Level Accuracy and Output Level Accuracy and Flatness 4 2 Performance Test 2 DC Level Accuracy 4 12 Performance Test 3 Distortion and Noise 4 14 Performance Test 4 Distortion SINAD and Signal to Noise Accuracy 4 16 Performance Test 5 Frequency Accuracy and Sensitivity 4 19 Performance Test 6 Audio Filters een 4 21 Performance Test 7 Input and Output 4 28 Performance Test 8 Common Mode
153. e beginning of a program string Frequency or Amplitude Increment Step Up or Step Down UP or DN When a Step Up UP or Step Down DN is executed the frequency or the amplitude is modified as determined by the established increment The parameter changed is dependent upon which increment command was executed last To insure the correct modification program either Frequency Increment FN or Amplitude Increment AN immediately before the UP or DN command Trigger Immediate and Trigger with Settling T2 T3 When either of the trigger codes 2 or T3 is received by the Audio Analyzer a measurement is immediately initiated Once the measurement is complete some bus commands can be processed without losing the measurement results However any HP IB program code sent to the Audio Analyzer before the triggered measurement results have been output will initiate a new measurement Thus trigger codes should always appear at the end of a program string and the triggered measurement results must be read before any additional program codes are sent Sending the Data Message Depending on how the internal address switches are set the Audio Analyzer can either talk only talk status only listen only or talk and listen both normal operation If set to both talk and listen the instrument sends Data messages when addressed to talk The instrument then remains configured to talk until it is unaddressed to talk by the controller To unaddress th
154. e commands to create a tone burst issue delays between commands For example when using an HP 9825A to obtain an approximate delay of 200 ms issue the command wait 200 Or when using an HP 85B issue the command WAIT 200 PROGRAM CODE RS is the program code for initiating the Rapid Source tuning mode The table below summarizes the Special Functions needed to acquire the tuning data Range 55 SP Coarse Tune 56 SP Fine Tune 57 SP INDICATIONS When in Rapid Source mode the Audio Analyzer s left display shows five dashes COMMENTS Within a single frequency range frequency switching is phase continuous RELATED SECTION Rapid Frequency Count 3 110 Rapid Source a a Model 8908 Operation RATIO and LOG LIN Special Function 11 DESCRIPTION The RATIO key can be used to compare any measurement except frequency and power to a reference value The reference value can be the result of a previous measurement or a keyboard entry The LOG LIN logarithmic linear key can be used to express the results in logarithmic or linear units The following table shows which units are applicable to the individual measurement modes Measurement RATIO On RATIO Ofi Mode PN NM NM AC LEVEL V or mV dBm into 6000 DC LEVEL V or mV dBm into 6000 SINAD dB SIG NOISE 96 dB DISTN 9o dB DISTN LEVEL dBm into 6000 After initial power on switchin
155. e message if issued and Local Lockout Sets the Service Request Condition to the 22 2 state Responds equally to Device Clear DCL and Selected Device Clear SDC bus DCL DC1 SDC commands RL1 Local The Audio Analyzer returns to local mode front panel control GTL RL1 Responds equally to the GTL bus command and the front panel LCL key When entering local mode no instrument settings or functions are changed but entries in progress are cleared In local triggering is free run only Local Disables all front panel keys including LCL and CLEAR Only LLO RL1 Lockout the controller can return the Audio Analyzer to local front panel control Clear The Audio Analyzer returns to local front panel control and RL1 local lockout is cleared when the REN bus contro line goes false When entering local mode no instrument settings or functions are changed but entries in progress are cleared In local triggering is free run only Lockout Set Local Pass Control The Audio Analyzer has no control capability CO Take Control Commands Control lines and Interface Functions are defined in IEEE Std 488 Knowledge of these might not be necessary if your controller s manua describes programming in terms of the twelve HP IB Messages shown in the left column 3 24 Model 8903B m Operation Table 3 3 Message Reference Table 2 of 2 ME Wl Require The Audio Analyzer sets the SRQ
156. e period of the signal is then counted the count is processed by the Controller and the frequency is displayed on the left display Source Frequency Measurement The Counter measures the frequency of the internal source only when the Oscillator is being tuned The frequency is normally not displayed To make a measurement of the source frequency the output of the Oscillator is fed into the Counter the period measured and the result processed by the Controller Source The source covers the frequency range from 20 Hz to 100 kHz It is tuned to the frequency entered from Keyboard by the Controller using a tune and count routine Note that the frequency is not obtained by frequency synthesis The switch following the Oscillator is normally closed except in the signal to noise ratio measurement mode or when an amplitude of 0V is entered from the Keyboard The output from the Oscillator is approximately 3V The Output Amplifier sets the source output level in fine steps The Floating Output Amplifier converts the single ended input into a floating signal either output can be grounded or floated up to 10V peak The Output Attenuator sets the output level in coarse steps The maximum signal to the OUTPUT connectors is 6V into an open circuit or 3V into the matching termination The output impedance of the source is HP IB programmable to either 50 or 6000 The keyboard selected level is the open circuit level General Information Model 8903B
157. e right display CCIR Weighting Filter Option 012 or 052 a Set HIGH PASS 400 Hz off if on Set FREQ to 6800 Hz Set RATIO off then back on b Press CCIR WEIGHTING Adjust A2A1R7 or A2A2R7 CCIR for a steady reading of 407 4 12 20 dB on the right display C Message Weighting Filter Option 013 or 053 a Set HIGH PASS 400 Hz off if on Set FREQ to 1 kHz Set RATIO off then back on b Press C MESSAGE WEIGHTING Adjust A2A1R6 or A2A2R6 CMSG for a steady reading of 100 0 on the right display 5 10 Adjustment 5 Model 8903B Adjustments CCIR ARM Weighting Filter Option 014 or 054 a Set HIGH PASS 400 Hz off if on Set FREQ to 6800 Hz Set RATIO off then back on b Press CCIR ARM WEIGHTING Adjust A2A1R7 or A2A2R7 CCIR for a steady reading of 213 8 6 6 dB on the right display A Weighting Filter Option 015 or 055 a Set HIGH PASS 400 Hz off if on Set FREQ to 1 kHz Set RATIO off then back on b Press A WEIGHTING Adjust A2A1R3 or A2A2R3 A WTD for a steady reading of 100 0 on the right display 3 Perform the Audio Filters Performance Test Performance Test 6 Adjustment 5 5 11 Adjustments Model 8903B Adjustment 6 NOTCH FILTER TUNE AND BALANCE ADJUSTMENT Reference Service Sheet 4 Description The Audio Analyzer is set to measure the distortion from its source The output from the notch filter is observed on an oscilloscope while the tuning and balance are adjust
158. e sweep are recognized and it is not necessary to hold them down while waiting for the Audio Analyzer to respond If the sweep is too fast for the X Y Recorder a delay of 1 second can be added between points by using Special Function 14 1 3 140 X Y Recording Model 8903B Operation RELATED SECTIONS AC Level DC Level SINAD Signal to Noise Distortion Distortion Level Plot Limit Special Functions Sweep Sweep Resolution Time Between Measurements X Y Recording 3 141 RELATIVE GAIN dB 98068 SPON 30 20 10 20 bk 1k 2k 500 FREQUENCY Hz 100 200 50 20 6 Theoretical RIAA Response Curve uorjered 8903 Performance Tests Section 4 PERFORMANCE TESTS 4 1 INTRODUCTION The procedures in this section test the instrument s electrical performance using the specifications of Table 1 1 as the performance standards All tests can be performed without access to the interior ofthe instrument A simpler operational test is included in Section 3 under Basic Functional Checks The Basic Functional Checks also test the instruments ability to function the automatic mode which is not thoroughly checked by the Performance Tests NOTE Unless otherwise noted a warm up period of 30 minutes is required for these tests Line voltage must be within 5 and 10 of the specified input voltage 100 120 220 or 240 Vac if the performance te
159. e to each instrument 3 11 Operation Model 8903B 3 5 BASIC FUNCTIONAL CHECKS Description Using only an oscilloscope the overall operation of the Audio Analyzer is verified OSCILLOSCOPE VERTICAL INPUT Figure 3 3 Basic Functional Checks Setup Equipment Oscilloscope METTE 1740 PROCEDURE Preliminary Check 1 Remove any cables from the Audio Analyzer s INPUT or OUTPUT Set the LINE switch to OFF then back to ON and note that the front panel LED annunciators display segments and decimal points and key lights turn on All LEDs should light for approximately three seconds 2 After the turn on sequence the left display should show 0 000 kHz and the right display should show a low flickering value in mV In addition the measurement cycle annunciator in the upper left hand corner of the right display should be blinking and the AC LEVEL and LOW PASS 80 kHz key lights should light 3 Connect a BNC to BNC cable between the HIGH OUTPUT and the HIGH INPUT See Figure 3 3 Set both FLOAT switches to the grounded position Set impedance to 500 by keying in 47 1 then pressing the SPCL button The SPCL key light should be lit 4 Connect the oscilloscope to the MONITOR output on the rear panel See Figure 3 3 AC Level and Output Level Check 5 Press AMPTD While the key is pressed 0 00 mV should show in the right display 6 Press 1 and V to set the amplitude to 1 Vrms The left display should show between 960 a
160. e vintage of the HP IB interface HP HPL used the Audio Analyzer s ADDRESSED annunciator may be either on or off The controller s display should read 0 00 HPL or 0 BASIC Require Service Message Description This check determines whether or not the Audio Analyzer can issue the Require Service message set the SRQ bus control line true This check assumes that the Audio Analyzer is able to handshake recognize its own address make the remote local changes and receive Data messages Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON then after the power up sequence is complete press the DISTN key Send the first part of the Remote message enabling the Audio Analyzer to remote Series 80 Controllers REMOTE 7 Series 200 300 Controllers REMOTE 728 OUTPUT 728 22 4SP Address the Audio Analyzer to listen completing the wrt 728 22 4SP Remote message then send a Data message enabling a Require Service message to be sent upon instrument Error Make the controller wait 2 seconds to allow time for wait 2000 WAIT 2000 the Audio Analyzer to send the Require Service message This step is not necessary if sufficient time is allowed Read the binary status of the controiler s HP IB interface and store the data in variable V in this Step 7 is the interface s select code rds 7 V Series 80 Controllers STATUS 7 V
161. ect sinusoid that is one whose frequency spectrum contains only a single spectral component Impurities are not always undesirable Impurities for example are what add character to the sound of musical instruments Pure signals in music sound monotonous However when testing a linear audio system if a pure signal is applied to the input anything but a pure signal at the output indicates that the system is degrading the signal There are several common classifications of impurities harmonic distortion harmonics of the fundamental intermodulation distortion beat signals of two or more non related signals noise random signals and spurious signals for example line hum and interference All but intermodulation distortion are easily measured by the Audio Analyzer Distortion Harmonic distortion on a spectrally pure signal is created by non linearities in the circuit through which it passes T he non linearities can arise in the transfer characteristics of the active devices or by running the active device into saturation or cutoff Often distortion can be reduced by reducing the signal level filtering or adding negative feedback According to Fourier mathematics the non linear terms in the circuit s transfer function give rise to harmonics of the signal Total harmonic distortion THD is usually defined as the ratio of the rms sum of the harmonics to the rms level of the fundamental The ratio is usually converted to or dB An o
162. ed wh 1 8 Electrical Equipment Available 1 8 HP IB Controllers ie iis oe ee Rie Beak we Bw Son he 1 8 Front to Rear Panel Connectors Retrofit Kit 1 8 Rear to Front Panel Connectors Retrofit Kit 1 8 Mechanical Equipment Available 1 9 Chassis Slide Mount Kit 9 luu ase ha UR VOY E ER OW E 1 9 Chassis Tilt Slide Mount 1 9 Recommended Test Equipment 1 9 Principles of Operation for Simplified Block Diagram 1 9 Voltmeter and Notch 1 10 ghi M c r 1 11 c c PX TT 1 11 Controllers cC 1 12 Basics of Audio Measurements 1 12 SP JE ET acento de oh E E Ee eee Se ek ws em eee ee a EET 1 12 BreQUOBCU hee ee a d s e ob LESE io up im 1 18 eS es ee te etd 1 18 Signal IMPUNES a 4 39 RU de de qd Edo t Hck AY cler p ote ge Sie 1 13 ro es We ee ac ne ey we 1 13 SINAD 5o
163. ed for a minimum The measured distortion is also monitored on the amplitude display Equipment OstilloBCODE owl EDI Made Pda doa Ed aa duce du HP 1740A OSCILLOSCOPE VERTICAL dila A me 92880 Bo c 88 56890 Eoo yer Fi AUDIO ANALYZER TEE Figure 5 3 Notch Filter Tune and Balance Adjustment Test Setup Procedure 1 On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Set the INPUT and OUTPUT switches both to ground Set AMPTD to 3V Set MEASUREMENT to DISTN Set LOG LIN to LOG 2 Connect the equipment as shown in Figure 5 3 3 Set the oscilloscope to view the ac signal at the rear panel MONITOR output Set the oscilloscope s trigger to external 4 Adjust A3R62 TUNE OFST and A3R63 BAL OFST for minimum signal and noise on the oscilloscope display 5 Observe the right display of the Audio Analyzer It should read 90 dB or less Readjust the two adjustments to minimize the reading on the display which must be 90 dB or less NOTE If the reading of step 5 cannot be brought within limit it may be that the source has excessive distortion 5 12 Adjustment 6 Model 8903B Adjustment Adjustment 7 VOLTMETER ADJUSTMENT Reference Service Sheets 6 and 7 Description The Audio Analyzer is set to measure the ac level from its source The internal ac to dc converter as yet uncalibrated produces a dc vol
164. ediately following the decimal point are optional For example when setting the load resistance to 10 19 1 is equivalent to 19 01 and 19 001 However 19 1 is not equivalent to 19 10 or 19 100 Note that 19 19 0 and 19 8 are equivalent that is they all specify an 8Q load resistance The displayed power level is accurate regardless of distortion unless the Audio Analyzer s audio detector is set to average responding Neither the RATIO nor the LOG function can be used with this Special Function RELATED SECTIONS AC level Detector Selection 3 56 Display Level in Watts uu Model 8903B Operation Display Source Settings Special Function 10 DESCRIPTION The currently programmed frequency and amplitude of the source can be simultaneously displayed by using Special Function 10 The programmed frequency is displayed in the left display and the programmed open circuit amplitude is displayed in the right display PROCEDURE display the currently programmed frequency and amplitude of the source press 10 0 then press the SPCL key EXAMPLE To display the source settings as Code Function LOCAL SPCL keystrokes 1 o 0 i x 10 0SP program codes Code Function PROGRAM CODES x 10 0SP is the HP IB code for Special Function 10 INDICATIONS As the numeric code is entered both displays will blank and the entered code will appear in the left display
165. eight appropriately to determine the number of cycle counts Assign that value to variable r6 Rapid Frequency Count 3 105 Operation Model 8903B Line 5 Since the Audio Analyzer uses a reciprocal counter the frequency of the input signal equals the number of input cycles r6 divided by total time elapsed during these input cycles T he denominator is determined by counting the number of 2 MHz clock counts that occur during these input cycles and multiplying by the frequency of the clock 2 MHz Total time equals number of clock counts divided by 2 10 6 Total time seconds Lib Thus Input frequency Hz A 2 2 106 Line 6 Displays the frequency count result Line 7 Terminates the program PROGRAM CODE x Program Code RF is the HP IB code that initiates the Rapid Frequency Count mode INDICATIONS When in Rapid Frequency Count mode the Audio Analyzer s left display will show gi COMMENTS The major advantage of Rapid Frequency Count mode is that data can be taken in rapid sequence and stored in an array in the computing controller Then at a later time when operations do not require immediate controller attention the packed binary data can be converted into decimal frequency data This way the time required for the Audio Analyzer to process the data into decimal frequency is eliminated This greatly increases its measurement speed for measuring tone burst sequences RELATED SECTION
166. ematical analysis Remote Operation 229 The Audio Analyzer is capable of remote operation visa the Hewlett Packard Interface Bus HP IB Instructions pertinent to HP IB operation cover all considerations and instructions specific to remote operation including capabilities addressing input and output formats the status byte and service requests At the end of the discussion is a complete summary of all codes and formats In addition to the section described above information concerning remote operation appears in several other locations Address setting is discussed in Section 2 Installation A summary of HP IB codes and output formats appear on one of the Operating Information pull out cards and numerous examples of program strings appear throughout the Detailed Operating Instructions described under Local Operation above 3 2 OPERATOR S CHECKS Operator s checks are procedures designed to verify the proper operation of the Audio Analyzer s main functions Two procedures are provided as described below Basic Functional Checks This procedure requires an oscilloscope and interconnecting cables It assumes that most front panel controlled functions are being properly executed by the Audio Analyzer HP IB Functional Checks This series of procedures require HP IB compatible computing controller and an HP IB interface and connecting cable The HP IB Functional Checks assume that front panel operation has been verified for example by
167. ement result would be 9 95 distortion instead of the true 10 Actually you can see that the distortion must really be excessive to affect the measurement significantly Now consider the case where other types of impurities are significant Suppose the actual total harmonic distortion is 1 but that there is an additional hum component that has a level 1 of the fundamental level The distortion measured by a distortion analyzer will be 1 4 that is 40 or 3 dB high How then can you be sure that the result is a valid measurement of distortion One way is to observe the rear panel MONITOR output with an oscilloscope If the waveform is clean and harmonically related to the fundamental the measurement is actual total harmonic distortion If it is not selectable filters are provided to remove unwanted signals Use the optional 400 Hz High Pass Filter to remove line hum Use the 30 kHz or 80 kHz Low Pass Filter to remove out of band noise However select only filters that do not affect the fundamental and the harmonics of interest Sometimes it is desired to include hum and noise as part of the distortion measurement For this reason the measurement is often referred to as a THD N total harmonic distortion plus noise measurement SINAD For most practical purposes the SINAD measurement as made by the Audio Analyzer is equal to the reciprocal of the distortion measurement It is usually expressed in dB The one subtle distinction is th
168. ench operation The plastic feet are shaped to ensure self aligning of the instruments when stacked The tilt stands raise the front of the instrument for easier viewing of the front panel Rack Mounting The Audio Analyzer is heavy for its size 12 3 kg 27 lb Care must be exercised when lifting to avoid personal injury Use equipment slides when rack mounting CAUTION DO NOT BLOCK the ventilation holes in the bottom panel Since this instrument does not use a cooling fan it is important that good ventilation be provided Allow for 1 to 2 inches clearance around the bottom panel Model 8903B Installation Table 2 1 Allowable HP IB Address Codes 4 Rack mounting information is provided with the rack mounting kits If the kits were not ordered with the instrument as options they may be ordered through the nearest Hewlett Packard office Refer to paragraph 1 13 Mechanical Options in Section 1 2 Installation Model 8903B 2 5 STORAGE AND SHIPMENT Environment The instrument should be stored in a clean dry environment The following environmental limitations apply to both storage and shipment Temberatiult ouai aa bcp ih ea en ada ea ee daba dne peines 55 C to 75 C HumilitU Sos ep eho IUE Ea qu N tuc Bae lt 95 relative PUG neve EORR RC E S iu es edo eee 15 300 meters 50 000 feet Packaging Original Packaging Containers and materia
169. ency and the amplitude settings entered for the source Special Function 10 Code Function LOCAL SPCL keystrokes a 0 ca Lo lt gt program codes Special Display When SPCL is pressed alone once and the following display results Q SUFFIXES PREFIXES 1 2 3 4 5 6 7 8 This display indicates that the following Special Functions were selected by the operator User Requested Setting Input Level Range Except DC Level 0 189V range Input Level Range DC Level only Automatic Selection Post Notch Gain Automatic Selection Hold Decimal Point DD DD mV range right display only Post Notch Detector Fast RMS Detector Filtering Except in SINAD Notch Tune Hold notch tuning SINAD Meter Range 0 to 24 dB range Error Disable Disable both analyzer and source errors Special Functions Model 8903B Operation Special Special Display When SPCL is pressed again while the Special Display is active and the following display results the actual instrument settings are tabulated below PLN u SUFFIXES PREFIXES it Actual instrument Setting Input Level Range Except DC Level 0 189V range Input Level Range DC Level only 300V range Post Notch Gain 60 dB Range Hold Decimal Point DD DD mV range Post Notch Detection Filtering Fast RMS Detector Except in SINAD Notch Tune Hold notch tuning SINAD Meter Range 0 to 24 dB range
170. end carriage return line feed or any other characters as delimiters The frequency data will be in the form shown below BYTE 1 BYTE 2 BYTE 3 BYTE 4 BBBB BBBB BBBB BBBB BBBB BBBB XXBB BBBB 260 minus 255 minus number of Least significant number of Most significant clock carries digit LSD of Cycle carries digit MSD of clock count clock count Second least significant Cycle count digit 2LSD of clock count To obtain the frequency compute Total clock counts LSD 16 2LSD 256 MSD 1024 260 BYTE 1 Total cycle counts Cycle count 16 255 BYTE 3 Frequency eyes Counts x 2 x 10 Where LSD Least significant digit of clock count 2LSD Second least significant digit of clock count MSD Most significant digit of clock count Rapid Frequency Count _ A MO ee NW Model 8903B Operation Using a BASIC controller such as the Hewlett Packard Model 85B Desktop Controller the computation is set up in seven steps as shown below 10 OUTPUT 728 USING K 46 1SPT3 RF 20 ENTER 728 USING B A B C D 30 T IP B 16 16 BINAND B 15 16 BINAND D 48 1024 260 A 40 E BINAND D 15 16 255 C 50 F IP E T 200000000 100 60 DISP F 70 END Explanation Line 10 Places the Audio Analyzer in the Rapid Count Mode 46 1SPT3 sets up the analyzer for transient free operation Line 20 Enter the four rapi
171. ent path flows from the INPUT connectors HIGH and LOW to the MONI TOR output on the rear panel and includes the Input RMS Average and Output RMS Average Quasi Peak Detectors dc voltmeter the Voltage to Time Converter and Counter and SINAD meter circuitry Measurements are made on the difference between the signals at the HIGH INPUT connector and the LOW INPUT connector or ground Differential and common mode levels can be as high as 300V Signals that are common to both the HIGH and LOW connectors are balanced out The input signal is ac coupled for all measurement modes except dc level The signal is scaled by the Input Attenuator to a level of 3V or less To protect the active circuits that follow the Over Voltage Protection circuit opens whenever its input exceeds 15V The differential signal is converted to a single ended signal that is a signal referenced to ground and amplified In the dc level mode the dc voltage is measured at this point by the dc voltmeter The signal is further amplified by a Programmable Gain Amplifier which is ac coupled The gain of this amplifier and the Differential to Single Ended Amplifier are programmed to keep the signal level into the Input Detector and Notch Filter between 1 7 and 3 Vrms to optimize their effectiveness and accuracy particularly in the distortion and SINAD modes The output from the first Programmable Gain Amplifier is converted to dc by the Ranging RMS Detector and measured by the dc
172. er of FREQUENCY Range Resolution Accuracy OUTPUT LEVEL Range Resolution Accuracy Flatness Distortion and Noise the higher of Impedance 80 dB or 17 uV 70 dB or 50 uV 65 dB or 50 uV 50 Hz to 100 kHz 0 to 99 99 dB 148 50 mV to 300V 85 dB or 17 uV 70 dB or 50uV 20 Hz to 100 kHz 0 396 increments 0 396 of setting 0 6 mV to 6V Better than 0 396 2 of setting 3 of setting 5 of setting 0 7 0 06 dB 2 5 0 22 dB 80 dB or 15uV 70 dB or 38uV 65 dB or 38uV 6000 1 500 2 20 Hz to 20 kHz 20 Hz to 50 kHz 50 kHz to 100 kHz 80 kHz BW 500 kHz BW Open circuit 60 mV to 6V open circuit 20 Hz to 50 kHz 6 mV to 6V open circuit 20 Hz to 100 kHz 0 6 mV to 6 mV open circuit 20 Hz to 100 kHz 20 Hz to 20 kHz 1 kHz reference 20 Hz to 100 kHz 1 kHz reference 20 Hz to 20 kHz 80 kHz BW 20 Hz to 50 kHz 500 kHz BW 50 kHz to 100 kHz 500 kHz BW Front panel selectable HP IB MEASUREMENT SINAD Fundamental Frequency Range Display Range Accuracy Input Voltage Range Residual Noise and Distortion the higher of rev 30DEC88 20 Hz to 100 kHz 0 to 99 99 dB 1 dB 2 dB 50 mV to 300V 80 dB 15 uV 70 dB or 45 uV 65 dB or 45 uV 20 Hz to 20 kHz unfiltered or with low pass filters 20 kHz to 100 kHz 20 Hz to 20 kHz 80 kHz BW 20 Hz to 50 kHz 500 kHz BW 50 kHz to 100 kHz 500 kHz BW General Information Model
173. feature gives the instrument greater flexibility in matching 500 or 6000 loads when making measurements The Audio Analyzer Source is set to 600 Impedance at power up PROCEDURE To select 500 impedance enter in Special Function code 47 1 then press the SPCL key To return the Source to 6000 impedance enter in Special Function code 47 0 and press the SPCL key or press the AUTOMATIC OPERATION key EXAMPLE To select 500 impedance s Code Function LOCAL SPCL keystrokes 4 em program codes PROGRAM CODE The above procedure gives the HP IB codes for special functions 47 0 and 47 1 Source Output Impedance may also be controlled over HP IB with these same special functions 47 0SP for 6000 impedance and 47 1SP for 500 impedance INDICATIONS The Impedance lamp will be on when the Source is set to 50 1 The Impedance lamp will be off when the Source is set to 6000 COMMENTS The most common line impedance used for RF applications is 500 With 500 line impedance you get higher short circuit current for a constant voltage and ten times the frequency response over a given length of cable than 6000 impedance For audio applications 6000 impedance is commonly used The following illustrations show the maximum power the instrument can deliver into various loads using the source output impedance feature Output Impedance 3 95 Operation OUTPUT IMPEDANCE SWITCH OUT
174. for the measurement results to be read While waiting the instrument can process most bus commands without losing the measurement results However if the instrument receives GTL Go To Local GET Group Execute Trigger its listen address or if it is triggered by the CLEAR key a new measurement cycle will be executed Once the data measurement results are read onto the bus the Audio Analyzer reverts to the Hold mode Measurement results obtained via Trigger Immediate are normally valid only when the instrument is in a steady settled state Trigger with Settling T3 Trigger with Settling is identical to Trigger Immediate except the Audio Analyzer inserts a settling time delay before taking the requested measurement This settling time is sufficient to produce valid accurate measurement results Trigger with Settling is the trigger type executed when a Trigger message is received via the bus Triggering Measurements with the CLEAR Key When the Audio Analyzer is in remote Hold mode and not in Local Lockout the front panel CLEAR key may be used to issue a Trigger with Settling instruction Place the instrument in Hold mode code T1 Each time the CLEAR key is pressed the Audio Analyzer performs one Trigger with Settling measurement cycle then waits for the data to be read Once the data is read out to the bus the instrument returns to Hold mode If data is not read between trigger cycles it will be replaced with data acquired from subsequen
175. g Special Function 16 1 Analog Meter active in SINAD only and for SINAD ratios lt 18 dB or lt 24 dB using Special Function 7 1 Accuracy 1 dB typical Tuning notch filter is tuned to analyzer source fre quency Time to Return First Measurement 1 5s typical Measurement Rate 2 0 readings s typical SIG NOISE Resolution Same as SINAD Measurement Rate One reading second for rms and average detectors one reading 2 seconds for quasi peak detector Detection True rms or rms calibrated average or quasi peak Time of Return First Measurement lt 2 5s typical Operation The Audio Analyzer displays the ratio of the input voltages as the internal source is switched on and off DISTORTION 3 dB Measurement Bandwidth 10 Hz to 500 kHz Detection True rms or rms calibrated average Displayed Resoiution 0 0001 lt 0 1 distortion 0 001 0 1 to 3 distortion 0 01 3 to 30 distortion 0 1 gt 30 distortion Time to Return First Measurement 1 5s typical Measurement Rate 2 readings s typical AC LEVEL AC Converter True rms responding detection for sig nals with crest factor of lt 3 rms calibrated aver age detection quasi peak detection Meets CCIR 468 3 standard 3 dB Measurement Bandwidth gt 500 kHz Time to Return First Measurement lt 1 5s typical Measurement Rate 2 5 readings s for rms and average detectors Quasi peak Detector Accuracy 20 Hz to 20 kHz 6 DC LEVEL Time to Retu
176. g measurement mode results in the configuration indicated by the asterisks In subsequent operations the last setting of the LOG LIN key is remembered for each measurement mode and applied to the new measurement When the RATIO LED is on the measurement result is compared to a reference value The reference value can be the result of a previous measurement or a keyboard entry The LOG LIN key allows any measurement result to be viewed in linear or logarithmic format The Audio Analyzer stores only one ratio reference at a time When in ratio if a new measurement is selected ratio is disabled When returning to the previous measurement it is possible to re enter the ratio mode with the same factor as before using Special Function 11 0 Additionally the ratio reference can be displayed using Special Function 11 1 PROCEDURE To use the RATIO key set the display to the desired reference value This can be done by adjusting the signal parameter being measured to a reference setting or by entering th reference on the numeric keys and then pressing RATIO If the numeric keys are used to enter the ratio reference the entry must be made in fundamental units that is for a ratio reference of 60 mV enter 06 regardless of the displayed value The display will show the measurement result relative to the reference value The units used with the right display depend upon the setting of the LOG LIN key see table above Pressing the LOG LIN key a
177. ght display should show 100 Reconnect the HIGH OUTPUT to the HIGH INPUT and set the INPUT switch to the ground position Press LOW PASS 80 kHz Verify that the LOW PASS 80 kHz key light goes off Press the STOP FREQ key While the key is pressed the left display should show 20 000 kHz the stop frequency setting at power up Press 100 kHz The left display should show between 99 70 and 100 30 kHz Press SWEEP During the sweep the SWEEP key light should light The source frequency sweeps Starting from approximately 20 Hz and stopping at approximately 100 kHz The right display should show between 96 and 104 throughout the entire sweep Filter Check 17 18 19 20 21 22 23 rev 0O40C T88 Press the LOG LIN key The right display should read approximately 0 00 dB Press LOW PASS 80 kHz Use the numeric data and units keys to set frequency but not the level of the source to approximately 80 kHz until the right display reads 3 dB The left display should show between 72 and 88 kHz Press LOW PASS 30 kHz The 30 kHz key light should light Adjust the frequency but not the level of the source to approximately 30 kHz until the right reads 3 dB The left display should show between 26 and 34 kHz Press LOW PASS 30 kHz again to turn it off If the instrument has Option 010 or 050 installed press the 400 Hz HIGH PASS key The 400 Hz HIGH PASS key light should light Adjust the frequency of the
178. gnal The output detector converts the residual noise distortion to dc The dc voltmeter measures the signal and the controller corrects for the programmed gain and attenuation The results are then displayed in the appropriate units The frequency of the input is also measured and displayed 3 60 Distortion Level Model 8903B Te J 1 FREQUENCY OUTPUT RMS AVG QUASI PEAK VOLTMETER im CONTROLLER HP 8P INPUT FILTERS NOTCH ATTENUATOR AMPLIFIER E FILTER E OUTPUT ATTENUATOR Cay Daum OSCILLATOR Use of the internal source is optional RMS DETECTOR bend AMPLIFIER Distortion Level Measurement Block Diagram RELATED SECTIONS Detector Selection Distortion Filters Monitor Notch tune RATIO and LOG LIN Operation COUNTER LEFT DISPLAY FREQUENCY 25500 WONITOR RIGHT DISPLAY AMPLITUDE Distortion Level 3 61 Operation Model 8903B Error Disable Special Function 8 DESCRIPTION The Error Disable Function is used to selectively disable operating error messages Using the 8 N Special Function allows the user to enable all operator error messages disable analyzer errors measurement related errors disable source errors output related errors or disable both analyzer and source errors PROCEDURE To selectively disable or enable operator error messages key in the corresponding Special Function code then press t
179. had been pressed last the programmed frequency or frequency increment would be changed Note that when using HP IB program codes the UP or DN commands increment or decrement the parameter that was last implemented for example FN or FR or AN or AP PROGRAM CODES lt gt Program Code Parameter a gt Frequency increment FN Amplitude Increment AN step up UP step down DN Frequency Units Hz kHz HZ KZ Amplitude Units V mV dB VL MV DB INDICATIONS The specific indications depend on the manner in which the keys are pressed For example momentarily pressing the FREQ INCR key will cause the currently programmed frequency increment to appear in the left display for approximately two seconds Pressing and holding the FREQ INCR key down will cause the currently programmed frequency increment to remain displayed until the key is released The AMPTD INCR key can be used in a similar manner to display the currently programmed value of the amplitude increment When using the 1 step up or step down keys the parameter that is incremented depends upon which of the source parameter keys that is FREQ FREQ INCR AMPTD or AMPTD INCR was pressed last Momentarily pressing causes the parameter to be incremented one step The new value of the source parameter can be observed by pressing FREQ or AMPTD as appropriate Remember that the programmed values for the source can differ from the displayed measure
180. he microprocessor then computes and displays the ratio of the on and off levels The ratio can be displayed in either 96 or dB In addition the source can be swept This makes measurements such as frequency response or complete distortion characterization simple to perform Microprocessor control allows flexible entry of source parameters and versatile display formats For example ac level can be displayed in V mV dBm into 6000 watts or as a ratio in or dB referenced to an entered or measured value Virtually all functions are remotely programmable through the Hewlett Packard Interface Bus HP IB Programming is easy and straightforward all measurements are made through a single input This eliminates the need to switch between multiple inputs under remote control and reduces software development time and hardware costs The Audio Analyzer measures the true rms level on all ac measurements True rms measurements assure greater accuracy when measuring complex waveforms and noise For those applications where average detection is required the analyzer can be switched to average responding rms calibrated detection through special functions Accurate distortion measurements typically can be made to less than 0 003 90 dB between 20 Hz and 20 kHz at a 1 5V level For those applications where quasi peak detection is required the analyzer Serial Prefix 2730A and above can be switched to this type of detection through special functions Th
181. he product input wiring terminals power cord or supplied power cord set SAFETY SYMBOLS Indicates instrument damage can occur if indicated operating limits are exceeded A Indicates hazardous voltages L Indicates earth ground terminal WARNING A WARNING note denotes a hazard It calls attention to a procedure practice or the like which if not correctly performed or adhered to could result in personal injury Do not proceed beyond a WARNING sign until the indicated conditions are fully understood and met CAUTION A CAUTION note denotes a hazard It calls attention to an operation procedure practice or the like which if not correctly performed or adhered to could result in damage to or destruction of part or all of the product Do not proceed beyond an CAUTION note until the indicated conditions are fully understood and met n M E 2 Chapter 1 Regulatory Information Updated March 1999 Safety Considerations for this Instrument WARNING This product is a Safety Class I instrument provided with a protective earthing ground incorporated in the power cord The mains plug shall only be inserted in a socket outlet provided with a protective earth contact Any interruption of the protective conductor inside or outside of the product is likely to make the product dangerous Intentional interruption is prohibited Whenever it is likely that the protect
182. he SPCL key Error Message Special Program Code Status Function Code um All error messages enabled 8 0 SPCL Disable analyzer error messages Errors 12 17 31 and 96 8 1 SPCL Disable source error messages Errors 18 and 19 8 2 SPCL Disable both analyzer and source error messages 8 3 SPCL EXAMPLE To disable the source error messages J Code Function LOCAL keystrokes x program codes Function PROGRAM CODES x For HP IB codes refer to Procedure above INDICATIONS As the numeric code is entered both displays will blank and the entered code will appear in the left display When the SPCL key is pressed the SPCL key will light except for Special Function 8 0 if it is not already on If it is already on it will remain on except for Special Function 8 0 Both displays then return to the display that is appropriate for the currently selected measurement mode 3 62 Error Disable Model 8903B Operation COMMENTS The error messages can be selectively disabled to prevent the analyzer error messages from halting the operation of the source section of the Audio Analyzer and vice versa The error messages can also be selectively disabled to prevent unwanted error interrupts to the HP IB bus controller Error messages are one means by which the instrument safeguards accurate measurements When these safeguards are disabled erroneous measurements can resul
183. he automatic notch tuning mode 3 78 Hold Settings 8908 RELATED SECTIONS Automatic Operation Special Functions Hold Settings 3 79 Operation x Model 8903B HP IB Address Special Function 21 DESCRIPTION The Audio Analyzer s present HP IB address can be displayed by using Special Function 21 This display is in binary or decimal When in binary Special Function 21 0 the right display shows whether the instrument is set to talk only or listen only and whether it is at present issuing a service request The left display shows the address in binary When in decimal Special Function 21 1 the display is shown as Addr NN where NN is the HP IB decimal address The address set at the factory is 28 in decimal 11100 in binary The HP IB address in decimal can also be viewed by pressing the shift key and then the LCL key PROCEDURE To display the HP IB address key in the appropriate Special Function code on the numeric keys then press the SPCL key To clear the display press the CLEAR key The instrument then reverts to the previous measurement mode A list of the Special Function codes is given below Program Code Display Special Function lt gt Binary 21 0 SPCL 21 0SP Decimal 21 1 SPCL 21 1SP A list of the allowable addresses for the Audio Analyzer is given below Allowable HP IB Address Codes Talk Address Switches Address Char Char 0 0
184. he cover door Figure 2 1 Line Voltage and Fuse Selection 2 3 Installation Model 8903B Cable Plug Plug 250V 8120 1351 90 STR BS1363A 8120 1703 90 90 250V 8120 1369 8120 0696 Mint Gray Mint Gray United Kingdom Cyprus Nigeria Rhodesia Singapore STR STR 79 Gray Austrailia NZSS198 ASC112 80 Gray New Zealand STR 90 250V 8120 1689 7 STR STR 79 Mint Gray East and West 8120 1692 2 STR 90 79 Mint Gray Europe Saudi 9 Arabia Egypt unpolarized in many nations 8120 1378 STR STR NEMA5 15P 80 Jade Gray United States 8120 1521 STR 90 80 Jade Gray Canada Mexico Phillipines Taiwan U S Canada 9 Jade Gray STR STR 100V STR STR Dark Gray Japan only Same plug as above STR 90 Dark Gray Japan only 0 90 90 250V STR STR SEV1011 79 Gray Switzerland 1959 24507 Type 12 8120 2296 STR 90 79 Gray 8120 3997 STR 90 177 Gray 79 79 9 4 4 250V 8120 0698 STR STR NEMA6 15P United States Canada 8120 2956 3 90 STR Gray Denmark 8120 2957 4 90 90 8120 3997 4 STR STR Black 7 Gray 59 31 8120 2191 STR 90 59 Jade Gray 8120 4379 90 90 80 Jade Gray Part number shown for plug is industry identifier for plug only Number shown for cable is HP Part Number for complete cable including plug E Earth Ground L Line N Neutrai STR Straight
185. ialize the instrument Set the INPUT switch to FLOAT Set LP FILTER off Key in 1 10 SPCL to set the input to the 4 76V range 19 Connect the ac calibrator output to the LOW INPUT of the Audio Analyzer Short the HIGH INPUT to ground 20 The right display of the Audio Analyzer should read between 4 4 and 4 6V Press RATIO 21 Set the ac calibrator frequency to 40 kHz Adjust A2C90 LOW 12 DB for a reading on the right display between 99 70 and 100 3 22 Set the ac calibrator frequency to 100 kHz Adjust A2C90 for a reading between 99 50 and 100 576 Repeat steps 21 and 22 as often as needed until the flatness at 40 kHz and 100 kHz is within the limits given See the following note Adjustment 2 Model 8903B 23 24 25 26 2 28 29 30 31 32 33 Adjustments NOTE If the flatness cannot be adjusted so that the 40 kHz and 100 kHz readings are both within the given limits change A2C89 as follows If the 100 kHz reading is higher than at 40 kHz decrease A2C4 by approximately 10 If the 40 kHz reading is higher than that at 100 kHz increase A2C89 by approximately 10 On the Audio Analyzer press RATIO to turn it off Key in 1 7 SPCL to set the input to the 18 9V range Set the ac calibrator frequency to 1 kHz and level to 15 Vrms The right display of the Audio Analyzer should read between 14 7 and 15 3V Press RATIO Set the ac calibrator frequency to 40 kHz Adjust A2C92 LOW 24 DB for a reading
186. ied functions Z Code s Functions LOCAL SPCL keystrokes 9 9 a gt 9 0SP program codes PROGRAM CODE x For HP IB code refer to Example above INDICATIONS As the numeric code is entered both displays will blank and the entered code will appear in the left display When the SPCL key is pressed the SPCL key LED will light if it is not already on If it is already on it will remain on The displays will then show the normal readings for the currently selected measurement mode COMMENTS Using Special Function 9 is equivalent to entering the following Special Functions from the keyboard 1 N Input Level Range Except DC Level 2 N Input Level Range DC Level Only 3 N Post Notch Gain 4 N Hold Decimal Point Right Display Only 6 1N Hold Notch Tuning For Special Functions 1 through 4 N is set equal to the currently selected value that the instrument is using for that function These values can be read by using the Special Special Display refer to Special Functions Note that using the Hold Settings Special Function can cause inaccurate measurements under some circumstances Once settings have been held by the Hold Settings Special Function one or more of them can be reset to their automatic modes by issuing the 0 suffix code of the corresponding Special Function As an example Hold Settings places the instrument in hold notch tuning mode Use 6 0 SPCL to re enter t
187. igit display NOTE The above numeric data input format information does not apply to the Rapid Source mode Refer to Rapid Source in the Detailed Operating Instructions Triggering Measurements with the Data Message feature that is only available via remote programming is the selection of free run standby or triggered operation of the Audio Analyzer During local operation the Audio Analyzer is allowed to free run outputting data to the display as each measurement is completed In remote except in sweep three additional operating modes are allowed Hold Trigger Immediate and Trigger with Settling In addition the CLEAR key can act as a manual trigger while the instrument is in remote The trigger modes and use of the Clear key are described below Free Run TO This mode is identical to local operation and is the mode of operation in effect when no other trigger mode has been selected The measurement result data available to the bus are constantly being updated as rapidly as the Audio Analyzer can make measurements A Device Clear message or entry into remote from local sets the Audio Analyzer to the Free Run mode NOTE Free Run triggering code TO is the only trigger mode allowed when using the sweep function code W1 Any other triggering codes T1 T2 or T3 or use of CLEAR key triggering will cause only the start frequency point to be displayed plotted and read to the HP IB Both the rear panel X AXIS and Y AXIS outputs
188. illustrated and described in Figure 3 1 For Option 001 the INPUT and OUTPUT HIGH and LOW connectors are located on the rear panel Rear panel features are shown in Figure 3 2 This figure provides a good quick reference for rear panel signal levels and also includes the impedance at the rear panel connections Detailed Operating Instructions The Detailed Operating Instructions provide the complete operating reference for the Audio Analyzer user The instructions are organized alphabetically by subtitle Not only do the instructions contain information on the various measurements that can be made listed under titles such as AC Level Distortion etc but there are also individual discussions of nearly all controls inputs and outputs for example Amplitude Monitor etc Also included are instructions for using the many User Special Functions for example Hold Settings Error Disable Special Functions etc The Detailed Operating Instructions are indexed by function in Table 3 2 Each section contains a general description which covers signal levels ranges and other general information Following the description are related procedures an operating example the relevant HP IB codes front panel indications and where pertinent a description of the technique the Audio Analyzer uses to make the measurement At the end of each discussion are comments intended to guide the user away from measurement pitfalls and to help get the most out of th
189. in watts into a specified resistance key in the corresponding Special Function code then press the SPCL key Resistance Special Function Program Code Q Code lt gt 19 0 SPCL 19 0SP 19 NNN SPCL where NNN 19 NNNSP corresponds to the load resistance in ohms EXAMPLE To set the right display to read INPUT signal level in watts into an external 160 speaker 4 Code a Functions LOCAL SPCL keystrokes a 9 C 1 6 8 x 19 16SP program codes PROGRAM CODES um For HP IB codes refer to Procedure above INDICATIONS As the numeric code is entered both displays will blank and the entered code will appear in the left display When the SPCL key is pressed the SPCL key will light if it is not already on If it is on it will remain on The right display shows a four digit readout of the ac power in watts but no units are indicated All measurement LEDs go off COMMENTS The load resistance in ohms must be an integer for example a resistance of 5 8 cannot be entered The decimal point has already been used when entering the Special Function attempt to enter a second decimal point is ignored Remember that the instrument assumes that the input voltage is being developed across the specified external load resistance If an incorrect resistance is entered the readout in watts is shown for the resistance entered Display Level in Watts 3 55 Operation Model 8903B Zeros imm
190. inserted into the audio signal path The filters limit the measurement bandwidth The high pass and bandpass filters are inserted before the notch filter control of the notch filter is covered in the Notch Tune discussion The low pass filters are inserted after the notch filter When in use the high pass bandpass and low pass filters always affect the signal at the rear panel MONITOR output PROCEDURE Select the desired signal filters by pressing the appropriate keys Only one high pass or bandpass and one low pass filter can be in use at a time To turn a filter off press the key again or select another filter in the same group HP IB codes for the different filter keys shown below turn on the selected filter defeating others in the group if on To turn a high pass or bandpass or low pass filter off via HP IB use code or LO respectively or select the alternate filter in the pair EXAMPLE To select the left high pass or bandpass filter and the 30 kHz low pass filter High Pass Bandpass Filter Low Pass Filter LOCAL HIGH PASS BANDPASS LOW PASS keystrokes 30 kHz x H1L1 program codes HP BP Fier Ld wipass Filter PROGRAM CODES x Program Program HP BP Filter Code LP Filter Code Both off Both off 750 kHz low pass Left HP BP Filter LOW PASS 30 kHz Right HP BP Filter LOW PASS 80 kHz INDICATIONS When a filter is activated by either automatic or manual selection the LED within that
191. ion has been impaired the instrument must be made inoperative and be secured against any unintended operation If this instrument is to be energized via an auto transformer for voltage reduction make sure the common terminal is connected to the earth terminal of the power source If this product is not used as specified the protection provided by the equipment could be impaired This product must be used in a normal condition in which all means for protection are intact only No operator serviceable parts in this product Refer servicing to qualified personnel To prevent electrical shock do not remove covers Servicing instructions are for use by qualified personnel only To avoid electrical shock do not perform any servicing unless you are qualified to do so The opening of covers or removal of parts is likely to expose dangerous voltages Disconnect the product from all voltage sources while it is being opened The power cord is connected to internal capacitors that my remain live for 5 seconds after disconnecting the plug from its power supply For Continued protection against fire hazard replace the line fuse s only with 250 V fuse s or the same current rating and type for example normal blow or time delay Do not use repaired fuses or short circuited fuseholders Always use the three prong ac power cord supplied with this product Failure to ensure adequate earth grounding by not using this cord may cause product
192. ion of the Hewlett Packard Interface Bus HP part number 5952 0156 ER rev 08A UG90 Model 8903B m Operation HP IB Compatibility The Audio Analyzer s complete bus compatibility as defined by IEEE Standard 488 and the identical ANSI Standard MC1 1 is described at the end of Table 3 3 Table 3 3 also summarizes the Audio Analyzer s HP IB capabilities in terms of the twelve bus messages in the left hand column Remote Mode Remote Capability In remote most of the Audio Analyzer s front panel controls are disabled exceptions are the LCL and CLEAR keys However front panel displays and the signal at various outputs remain active and valid In remote the Audio Analyzer may be addressed to talk or listen When addressed to listen the Audio Analyzer will respond to the Data Trigger Clear SDC and Local messages When addressed to talk the Audio Analyzer can issue the Data and Status Byte messages Whether addressed or not the Audio Analyzer will respond to the Clear DCL Local Lockout Clear Lockout Set Local and Abort messages and in addition the Audio Analyzer may issue the Require Service message Local to Remote Mode Changes The Audio Analyzer switches to remote operation upon receipt of the Remote message The Remote message has two parts They are e Remote enable bus control line REN set true e Device listen address received once while REN is true When the Audio Analyzer switches to remote both the R
193. ipment AC Calibrator obese HP 745A or Datron 4200 or Fluke 5200A Procedure High Input Flatness 1 Set the ac calibrator to 1 kHz at 4 5 Vrms 2 On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Set the INPUT switch to ground Set LP FILTER off Key in 1 10 SPCL to set the input to the 4 76V range 3 Connect the ac calibrator output directly to the HIGH INPUT of the Audio Analyzer 4 The right display of the Audio Analyzer should read between 4 4 and 4 6V Press RATIO 5 Set the ac calibrator frequency to 40 kHz Adjust A2C3 HIGH 12 DB for a reading on the right display between 99 70 and 100 396 6 Set the ac calibrator frequency to 100 kHz Adjust A2C3 for a reading between 99 50 and 100 5 Repeat steps 5 and 6 as often as needed until the flatness at 40 kHz and 100 kHz is within the limits given See the following note Adjustment 2 5 5 Adjustments Model 8903B 0 6 NOTE If the flatness cannot be adjusted so that the 40 kHz and 100 kHz readings are both within the given limits change A2C4 as follows If the 100 kHz reading is higher than at 40 kHz decrease A2C4 by approximately 10 If the 40 kHz reading is higher than that at 100 kHz increase A2C4 by approximately 10 7 On the Audio Analyzer press RATIO to turn it off Key in 1 7 SPCL to set the input to the 18 9V range 8 Set the ac calibrator frequency to 1 kHz and level to 15 Vrms 9 The right display of the
194. is detector is designed to meet the requirements specified by CCIR 468 3 Audio Testing The Audio Analyzer has numerous features which make audio testing simple and convenient These features include flexible data entry and display formats convenient source control and swept measurements capability For example distortion results can be displayed in or dB AC level measurements can be displayed in volts dBm into 6009 or watts Measurement results can be displayed in 96 or dB relative to a measured or entered value Finding the 3 dB points of filters and amplifiers is simplified by using the source frequency increment and decrement keys together with the relative display feature A major contribution of the Audio Analyzer is its ability to make swept measurements When sweeping the Audio Analyzer tuning steps its source frequency in logarithmic increments With an x y recorder hard copy measurement results can be obtained X axis scaling is determined by the entered start and stop frequencies Y axis scaling is determined by the measurement units selected and the plot limits entered through the keyboard valid display units except mV are allowed when plotting To change the scaling from frequency response to swept distortion plots simply key in new HP IB Not just IEEE 488 but the hardware documentation and support that delivers the shortest path to a measurement system 1 3 General Information Model 8903B val
195. ise time coupled with a slow decay time is used to capture impulse type signals or other signals noise or waveforms with high crest factors The Quasi peak Detector when used with the optional CCIR weighting Filter gives signal to noise measurement results which more accurately correlates with perceived signal to noise ratios Detector Selection 3 53 Operation Model 8903B COMMENTS Many ac voltmeters employ an average responding detector For those applications requiring the use of an average responding detector select either 5 2 SPCL for fast average or 5 3 SPCL for slow average special functions One feature of the Quasi peak Detector is that the displayed response drops as the repetition rate of the measured signal decreases Because there is only one Quasi peak Detector part of the Output Detector you will not get meaningful measurements for Distortion or SINAD Using the Quasi peak Detector for Distortion or SINAD measurements is not recommended RELATED SECTIONS AC Level Distortion Distortion Level SINAD Signal to Noise 3 54 Detector Selection Model 8908 Operation Display Level in Watts Special Function 19 DESCRIPTION The measurement mode can be set to read the ac input power in watts into a specified external load resistance by using Special Function 19 The range of the selectable load resistance in ohms is an integer value from 1 to 999 PROCEDURE To set the measurement to display the ac level
196. itch FLOAT switches the 10 or x10 keys and the Controller Reset Service Special Function In addition the Audio Analyzer may be triggered via data messages to make measurements at a particular time Receiving the Data Message Depending on how the internal address switches are set the Audio Analyzer can either talk only talk status only listen only or talk and listen both normal operation The instrument responds to Data messages when it is enabled to remote REN control line true and it is addressed to listen or set to Listen Only If not set to Listen Only the instrument remains addressed to listen until it receives an Abort message or until its talk address or a universal unlisten command is sent by the controller Listen Only If the internal LON Listen Only switch is set to 1 the Audio Analyzer is placed in the Listen Only mode when the remote enable bus control line REN is set true The instrument then responds to all Data messages and the Trigger Clear and Local Lockout messages However it is inhibited from responding to the Local or Abort messages and from responding to a serial poll with the Status Byte message Listen Only mode is provided to allow the Audio Analyzer to accept programming from devices other than controllers for example card readers Data Input Format The Data message string or program string consists of a series of ASCII codes With the exception of the Rapid Source mode each code is typi
197. ithin the SPCL key will turn on if not already on If the light is already on it will remain on The LED will not turn on if Special Function code 5 0 is entered The LED wil turn off when both 5 0 SPCL and 47 0 SPCL are entered 3 100 Post Notch Detector Filtering except SINAD rev 20 UN9I 8908 Operation COMMENTS When the Audio Analyzer is first turned on or when AUTOMATIC OPERATION is selected the fast rms detector is selected In SINAD additional low pass filtering is always used Fast detection either rms or average cannot be selected by means of keyboard entry using the SPCL key when in SINAD Slow detection can be used when in SINAD RELATED SECTIONS Automatic Operation Special Functions Post Notch Detector Filtering Except SINAD 3 101 Operation Model 8903B Post Notch Gain Special Function 3 DESCRIPTION The overall stage gain of the post notch circuit can be manually set by keyboard entry using the SPCL key The gain is selectable from 0 dB to 60 dB in 20 dB steps In automatic operation mode the instrument will automatically select the optimum post notch gain PROCEDURE To manually set the gain of the post notch circuit or to re enter the automatic selection mode key in the corresponding Special Function code then press the SPCL key P Post Notch Gain Special Function Code Aum Automatic Selection 3 0 SPCL 0 dB gain 3 1 SPCL 20 dB gain 3 2 SPCL 40 dB g
198. itude SERE EL _ lt ee Model 8903B Operation COMMENTS The Audio Analyzer powers up with the source frequency set to 1 kHz and amplitude set at OV NOTE When the source output is set to OV maximum output attenuation ts not necessarily selected to minimize wear on the output attenuator If full output attenuation is not selected then noise is not held to a minimum level For minimum noise first select 6 mV source output then select 0V When the AMPTD key is pressed and held the right display shows the currently programmed amplitude It is important to realize that the value shown in the right display is the programmed value which can differ from the actual value at the OUTPUT For example when the source output impedance is 6000 the voltage developed across an external 6000 load will be half the programmed value RELATED SECTIONS Display Source Settings Frequency Increment Output Impedance Amplitude 3 45 Operation Model 8903B Automatic Operation DESCRIPTION The AUTOMATIC OPERATION key sets the instrument functions to automatic that is each function is allowed to automatically range to the appropriate setting It also cancels all functions that light the SPCL key light PROCEDURE To set the Audio Analyzer to automatic operation press the AUTOMATIC OPERATION key EXAMPLE To set the Audio Analyzer to automatic
199. key AC level results can be displayed in V mV dBm into 6002 watts or as the ratio to an entered or measured value The Audio Analyzer powers up displaying ac level in linear units mV or V To obtain a display in dBm that is dB relative to 1 milliwatt into a 6002 load equivalent to dBre 0 775V press the LOG LIN key To return to linear simply press the LOG LIN key again If the ac level is to be displayed relative to a reference refer to RATIO and LOG LIN EXAMPLE To measure the ac level of a signal at the INPUT jacks 7 Measurement LOCAL AC LEVEL keystrokes gm 423 1 program codes Measurement PROGRAM CODE x M1 is the program code for AC LEVEL INDICATIONS When ac level is selected the LED within the AC LEVEL key will light The right display shows the ac level with the appropriate units The Audio Analyzer automatically ranges for maximum resolution and accuracy The left display shows the input signal frequency If the input level to the frequency counter is too small the left display will show 0 000 kHz This will often occur when the signal is in the stop band of the optional high pass or weighting bandpass filters but not the low pass filters MEASUREMENT TECHNIQUE In ac level the Audio Analyzer acts as an ac voltmeter The Audio Analyzer automatically sets the input attenuation and the gain settings of the various amplifiers so that the input signal amplitude lies within the range of the outp
200. l are per formed with power supplied to the instrument while protective covers are removed Energy available at many points may if contacted re sult in personal injury Capacitors inside the instrument may still be charged even if the instrument has been dis connected from its source of supply For continued protection against fire hazard replace the line fuse s only with 250V fuse s of the same current rating and type for exam ple normal blow time delay etc Do not use repaired fuses or short circuited fuseholders Model 8903B ATTENTION Static Sensitive Devices This instrument was constructed in an ESD electro static dis charge protected environment This is because most of the semi conductor devices used in this instrument are susceptible to damage by static discharge Depending on the magnitude of the charge device substrates can be punctured or destroyed by contact or mere proximity of a static charge The results can cause degradation of device performance early failure or immediate destruction These charges are generated in numerous ways such as simple con tact separation of materials and normal motions of persons working with static sensitive devices When handling or servicing equipment containing static sensitive devices adequate precautions must be taken to prevent device dam age or destruction Only those who are thoroughly familiar with industry accepted techniques for handling stati
201. l contains information required to install operate test adjust and service the Hewlett Packard Model 8903B Audio Analyzer This manual documents options installed in the Audio Analyzer such as rear panel connections and internal plug in filters This section of the manual describes the instruments documented by the manual and covers instrument description options accessories specifications and other basic information This section also contains principles of operation on a simplified block diagram level and basic information on audio measurements The other sections contain the following information Section 2 Installation provides information about initial inspection preparation for use including address selection for remote operation and storage and shipment Section 3 Operation provides information about panel features and includes operating checks operating instructions for both local and remote operation and maintenance information Section 4 Performance Tests provides the information required to check performance of the instrument against the critical specifications in Table 1 1 Section 5 Adjustments provides the information required to properly adjust the instrument Section 6 Replaceable Parts provides ordering information for all replaceable parts and assemblies Section 7 Instrument Changes provides instrument modification recommendations and procedures Section 8 Service provides the information required to
202. l of the input signal The output detector converts the residual noise 4 distortion to dc The dc voltmeter measures both dc signals The controller then corrects for the programmed gain and attenuation computes the ratio of the two signals and then displays the results in appropriate units The frequency of the input signal is also measured and displayed COMMENTS Distortion can be measured with either the true rms or average responding detector Most applications specify true rms detection Using the Quasi peak Detector for Distortion measurements is not recommended COUNTER LEFT DISPLAY FREQUENCY FREGUENCY OUTPUT RMS AVG FILT NOTCH ERUATOR dcus FILTER QUASI PEAK voLTMETER RIGHT DISPLAY L FILTER DETECTOR CONTROLLER AMPLITUDE meme 75 ieee Tea S N D RANGING at ira cr DETECTOR AMPLIFIER ATTENUATOR OSCILLATOR Use of the internal source optional Distortion Measurement Block Diagram RELATED SECTIONS Detector Selection Distortion Level Filters Notch Tune RATIO and LOG LIN Distortion 3 59 Operation Model 8903B Distortion Level DESCRIPTION The Audio Analyzer measures the distortion level by removing the fundamental of the input signal and then measuring the ac level of the remaining noise and distortion The mV and V units are displayed in the linear mode or the values are converted to dBm that is dB relative to 1 milliwatt into 6002 load equiva
203. l s size loudness frequency pitch and shape timbre You can also determine if these parameters change with time or are stable and you can even make some quantitative measurements on it for example peak level dc offset period risetime etc Many times however the parameter sought does not lend itself to easy visual analysis Thus the Audio Analyzer was designed It combines into one instrument a series of general and specialized instruments under microprocessor control that make it easy for you to obtain accurate quantitative measurements on audio signals of any general waveshape AC Level Consider the very common measurement of a signal s ac rms level To make this measurement with an oscilloscope you must first decide the nature of the signal because from it the relationship of the peak level to the rms level can be mathematically determined If the signal is sinusoidal for example the rms value is the peak amplitude divided by 2 This measurement is greatly simplified with a rms voltmeter which electronically measures the rms level and displays the result However no other information about the signal is provided The Audio Analyzer contains both an rms and an average responding voltmeter The rms level of the signal is displayed whenever the AC LEVEL mode is selected The average level can be displayed by entering 5 2 SPCL The quasi peak level can be displayed by entering 5 7 SPCL A special function is also provided whi
204. lay resolution measurement selection and many other operations can be manually controlled Manual Operation All Audio Analyzer operations except the LINE switch two FLOAT switches and the 10 and x 10 FREQ AMPT ADJUST keys can be controlled via the Hewlett Packard Interface Bus Remote Operation Operation Model 8903B 3 3 FRONT PANEL FEATURES Figure 3 1 Front Panel Features 1 HP IB Annunciators indicate remote operation status 2 LCL local key returns the Audio Analyzer to keyboard control from remote HP IB control 3 START and STOP FREQ keys display or initiate entry of the start and stop frequencies of the SWeep 4 FREQ and FREQ INCR keys display or initiate entry of the frequency and frequency increment of the source 5 AMPTD and AMPTD INCR keys display or initiate entry of the amplitude or amplitude increment of the source 6 The two Numeric Displays show the frequency measurement results numeric key entries error codes or instrument or Special Function status 7 Frequency Display Annunciators indicate the frequency units 8 MEASUREMENT CYCLE indicator blinks after each measurement cycle 9 Unit keys select units and complete manual data entry 10 AUTOMATIC OPERATION key switches instrument to automatic ie functions allowed to automatically range as appropriate 11 Measurement Display Annunciators indicate the measurement result units 12 RATIO key causes measurement
205. lect code of the controllers HP IB interface is assumed to be 7 The address of the Audio Analyzer is assumed to be 28 its address as set at the factory This select code address combination that is 728 is not necessary for these checks to be valid However the program lines presented here would have to be modified for any other combination These checks are intended to be as independent of each other as possible Nevertheless the first four checks should be performed in order before other checks are selected Any special initialization or requirements for a check are described at its beginning Initial Setup The test setup is the same for all of the checks Connect the Audio Analyzer to the bus controller via the HP IB interface Do not connect any equipment to the Audio Analyzer s INPUT Equipment HP IB Controller HP 9825A 98213A General and Extended I O ROM UO ERNEUT TERR Oe beeen HP 85B Option 007 NOCT NUTRIT T HP 9000 Model 226 or any HP 9000 series 200 Computer Address Recognition Description This check determines whether or not the Audio Analyzer recognizes when it is being addressed and when it is not This check assumes only that the Audio Analyzer can properly handshake on the bus Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON Set the Remote Enable REN bus control line false icl 7 LOCAL 7 Send the Audio Analyzer s listen ad
206. lent to 0 7 5 V The RATIO key can be used to compare the measured results to a predetermined ratio reference refer to RATIO and LOG LIN PROCEDURE To make a distortion level measurement press the S Shift and DISTN LEVEL keys If the internal source is to be used as a stimulus signal key in the desired frequency and amplitude The filters are used to limit the bandwidth The Audio Analyzer powers up with the LOW PASS 80 kHz filter activated EXAMPLE To measure distortion level on an external source signal in a 30 kHz bandwidth 7 Measurement Filter LOCAL Le jjo LOW PASS 30 kH keystrokes LEVEL x S3L1 program codes Measurement Filter PROGRAM CODE m S3 is the HP IB code for distortion level INDICATIONS When distortion level is selected the LEDs in the S Shift key and the DISTN LEVEL key will light The frequency and amplitude of the input signal are displayed and the appropriate annunciators will light see Description above MEASUREMENT TECHNIQUE In the distortion level measurement mode the controller automatically sets the input attenuation and the gain settings of various amplifiers This control ensures that the signal amplitude is within the proper range for the output detector The notch filter removes the fundamental from the input signal The notch filter automatically tunes to the component whose frequency is measured by the counter usually the fundamental of the input si
207. limits first press the PLOT LIMIT key to initiate entries To enter an upper plot limit press the appropriate numeric data keys then the UPPER LIMIT key Similarly to enter a lower plot limit press the appropriate numeric data keys then the LOWER LIMIT key Once the PLOT LIMIT key has been pressed new plot limits can be successively entered until another source function key for example FREQ key is pressed To display the currently programmed plot limits press and hold the PLOT LIMIT key EXAMPLE To enter an upper limit of 20 and a lower plot limit of 10 Function 7 Data jermination 2 0 fas Data Termination s LOWER LIMIT UPPER LIMIT LOCAL keystrokes PL20UL 10LL x Function program codes Data Data Terminator PROGRAM CODE uM omo xm PLOT LIMIT PL UPPER LIMIT UL LOWER LIMIT LL 3 98 Plot Limit ig pg ML ee LIUM Model 8903B Operation INDICATIONS When the PLOT LIMIT key is pressed both displays will show the currently programmed plot limits The upper limit appears on the right display and the lower limit appears on the left display As a new upper or lower plot limit is entered it will appear on the left display When the UPPER LIMIT or LOWER LIMIT key is pressed the left display returns to show the input signal frequency and the right display returns to show the measurement previously selected
208. lly used in the Talk Only Mode when logging data to a monitoring device Note that when set to Listen Only the Audio Analyzer can not place data on the bus If it is set to talk and listen both front panel control is relinquished and HP IB codes RR and RL determine the data output PROCEDURE To set the Audio Analyzer to output data to the HP IB from either the left or right display key in the corresponding Special Function code and then press the SPCL key Display Special Function Program Code Read Code m Right 20 0 SPCL 20 0SP or RR Left 20 1 SPCL 20 1SP or RL EXAMPLE To read the left display to the HP IB keystrokes x 20 1SP OR RL program codes Function PROGRAM CODES x For HP IB codes refer to the table in the Procedure above INDICATIONS As the numeric code is entered both displays will blank and the entered code will appear in the left display When the SPCL key is pressed the SPCL key does not light However both displays will again blank and four dashes will momentarily appear in the right display Both displays then return to the display that is appropriate for the current measurement mode 3 114 Read Display to HP IB Model 8903B Operation HP IB OUTPUT x The instrument outputs data from the display in the following format t DDDDDE NNCRLF Bytes 11 and 12 CR LF carriage return line feed Bytes 9 and 10 Two digit exponent Byte 8 Sign of e
209. ls identical to those used in factory packaging are available through Hewlett Packard offices If the instrument is being returned to Hewlett Packard for servicing please fill out one of the blue tags located at the end of this manual Include on the tag the type of service required return address model number and full serial number and attach it to the instrument Mark the container FRAGILE to assure careful handling In any correspondence refer to the instrument by model number and full serial number Other Packaging The following general instructions should be used for re packaging with commer cially available materials 1 Wrap the instrument in heavy paper or plastic If shipping to a Hewlett Packard office or service center complete one of the blue tags mentioned above and attach it to the instrument 2 Use a strong shipping container doublewall carton made of 1 9 MPa 275 psi test material is adequate 3 Use enough shock absorbing material 75 to 100 mm layer 3 to 4 inches around all sides of instrument to provide a firm cushion and prevent movement in the container Protect the front panel with cardboard 4 Seal the shipping container securely 5 Mark the shipping container FRAGILE to assure careful handling Model 8903B Installation SIGNAL GROUND SHIELD CONNECT TO P O TWISTED PAIR WITH 11 ATN EARTH P O TWISTED PAIR WITH 10 SRO GROUND SHOULD BE GROUNDED P O TWISTED PAIR WITH 9 IFC
210. lternates the display between the LOG and the LIN functions When the measurement mode is changed the last setting of the LOG LIN key for that mode is remembered and applied to the new measurement RATIO and LOG LIN 3 111 Model 8903B To re enter ratio with the previous ratio reference or to read the reference key in the corresponding Special Function code and press the SPCL key The Special Function codes are listed as follows Program Code Ratio Operation Special Function Code Re enter ratio with the previous reference 11 0 SPCL Read ratio reference 11 1 SPCL EXAMPLES If the display shows 100 mV to enter this value as the RATIO reference for future measurements Ration LOCAL keystrokes lt gt program codes If the display shows 0 100V to compare this to a value of 2V y7 Data Ratio LOCAL keystrokes 2 e RATIO gt program codes PROGRAM CODES The HP IB codes for re entering ratio or for reading the reference are given above The HP IB codes for the RATIO and LOG LIN keys are given below LOG LG LIN RATIO Off RATIO On 3 112 RATIO and LOG LIN Model 8903B Operation INDICATIONS When the instrument is displaying a ratio measurement the RATIO key lights The status of the LOG LIN key can be determined by observing the current measurement mode the measurement unit lights and the table above COMMENTS The ra
211. mal value of the instrument s HP IB address 28 if it has not been changed EXAMPLES To display the HP IB address in binary and the status of the L and S bits s Code Function LOCAL SPCL keystrokes 2 1 0 lt gt program codes If the following is displayed then the HP IB address is 11100 in binary 28 in decimal In ASCII the talk address is and the listen address is lt The instrument is not set to talk or listen only but it is issuing a service request setting the SRQ control line true HP IB Address 3 81 Operation Model 8903B To display the HP IB address in decimal sm Code Function LOCAL SPCL keystrokes m 21 1SP ee ee program codes Assuming the same address the following will be displayed PROGRAM CODE x For HP IB codes refer to Procedure COMMENTS The HP IB address display is continuously updated This makes setting the address easy since the result of changing a switch setting is immediately visible on the display For information on setting the HP IB address of the Audio Analyzer refer to Section 2 of this manual The factory set address is as shown in the examples decimal 28 The T and L bits are set to 0 T he S bit is 0 at instrument power up RELATED SECTIONS Special Functions Remote Operation Hewlett Packard Interface Bus 3 82 HP IB Address Model 8903B Operation In
212. ment values Pressing and holding the 1 or keys down causes the parameter to be stepped continuously The effect of the change on the measurement results can be seen on the displays Pressing the or x 10 key modifies the currently programmed parameter that is active as indicated Note that to repeat the division or multiplication of the parameter the key must be pressed again Holding these keys down do not cause additional multiplication or division of the source parameter COMMENTS Neither the or x 10 keys are HP IB programmable Remember that all FREQ AMPTD ADJUST key operations depend upon source parameter informa tion previously input to the Audio Analyzer for example FREQ AMPTD etc The amplitude can be incremented in either linear units V or mV or logarithmic units dB regardless of the units used to program the amplitude originally Incrementing frequency in relatively small steps may give unexpected results due to the tuning routine The frequency may increment not at all more or less than requested or even in the opposite direction When a new frequency is entered whether as an absolute frequency or as a frequency increment the controller tunes the source until the frequency is within 0 2 of the entered input The tuning routine is repeated for each new input When within the 0 2 range of the new input tuning ceases whether the entered increment has occured or not 3 84 Increment Model 8903B Operation REL
213. mmand whether addressed or not The Clear message clears any pending Require Service message and resets the Service Request Condition Special Function 22 such that the Require Service message will be issued on HP IB code errors only 22 2 SPCL Receiving the Trigger Message When in remote and addressed to listen the Audio Analyzer responds to a Trigger message by executing one settled measurement cycle The Audio Analyzer responds equally to a Trigger message the Group Execute Trigger bus command GET and a Data message program code T3 Trigger with Settling Refer to the paragraph Triggering Measurements with the Data Message under Receiving the Data Message 4 8903 3 32 Receiving the Remote Message The Remote message has two parts First the remote enable bus control line REN is held true then the device listen address is sent by the controller These two actions combine to place the Audio Analyzer in remote mode Thus the Audio Analyzer is enabled to go into remote when the controller begins the Remote message but it does not actually switch to remote until addressed to listen the first time No instrument settings are changed by the transition from local to remote but the Trigger mode is set to Free Run code TO When actually in remote the Audio Analyzer lights its front panel REMOTE annunciator When the Audio Analyzer is being addressed whether in remote or local its fron
214. n Model 8903B Errors which are signified by the two dashes or four dashes on the right display stop the sweep but do not take the instrument out of sweep mode soon as the error causing condition is removed the sweep starts again from where it left off Nonrecoverable errors such as Error 10 Error 11 etc require that the error causing condition be removed and the error message be cleared before another sweep can be initiated Note that the sweep cannot continue from the frequency point at which the error first occurred The time required to complete a sweep depends on factors such as measurement mode sweep width sweep resolution and input signal level RELATED SECTIONS 3 132 Plot Limit Sweep Resolution X Y Recording Sweep Model 8908 Operation Sweep Resolution Special Function 17 DESCRIPTION The Audio Analyzer powers up with a sweep resolution of 10 points decade However the sweep resolution can be manually selected from 1 to 500 points decade by keyboard entry using the SPCL key PROCEDURE To select a different sweep resolution key in the corresponding Special Function code then press the SPCL key Sweep Resolution Special Function Code um Cade 10 points decade 17 0 SPCL 1 point decade 17 1 SPCL 2 points decade 17 2 SPCL 5 points decade 17 3 SPCL 10 points decade 17 4 SPCL 20 points decade 17 5 SPCL 50 points decade 17 6 SPCL 100 points decade 17 7 SPCL 200 points decade 17 8 SPCL
215. n Accuracy 0 075 dB to 0 3 mV range Computing HP IB compatibility as defined by IEE std 488 and the HP 9825A Controller identical ANS1 Std MC1 1 SH1 AH1 T2 TEO L2 LEO SRO 98034A 98213A PPO DCO DTO and C1 2 3 4 5 or HP 85B Opt 007 DC Standard Output Range 3 mV to 300V HP 7408 or Accuracy 0 1 0 3mV Datron 4000 or Fluke 893AR AC Accuracy 0 2 at 6 Vrms and 1 kHz HP 3455A DC Accuracy 0 2 at 1V Feedthrough Impedance 500 HP 11048C Termination Impedance Accuracy 1 Maximum Dissipation 180 mW Feedthrough Impedance 6000 HP 11095A Termination Impedance Accuracy 1 iul Maximum Dissipation 100 mW Standard Accuracy 1 ppm Oscilloscope Bandwidth 3 dB down 0 to 10 MHz HP 1740C CAT Sensitivity 5mV per division minimum Input Impedance 1 MQ Triggering Internal and External Power Supply Output to 15V Resistor 100k Accuracy 0 1 HP 0698 7497 EM Signature Because the signatures documented are unique to a given HP 5005A T Analyzer signature analyzer type no substitution of types is recommended Output 30 Vpp HP 8904A HP 8904A Multifunction Texscan Synthesizer FP 50 20dB Frequency Range 20Hz to 350 kHz Frequency Accuracy 4 ppm Output Range 9V p p into 500 Flatness 0 09dB 20Hz to 350kHz 20 dB Pad Attenuation 20 dB 0 1 dB Frequency Range 20 Hz to 100 kHz Impedance 500 C Operator s Check
216. n circuit 20 Hz to 100 kHz 5 of setting 0 6 mV to 6 mV open circuit 20 Hz to 100 kHz Flatness 0 7 0 06 dB 20 Hz to 20 kHz 1 kHz reference 2 5 0 22 dB 20 Hz to 100 kHz 1 kHz reference MEASUREMENT AC LEVEL Accuracy 50 mV to 300V 20 Hz to 20 kHz 50 mV to 300V 20 kHz to 100 kHz 0 3 mV to 50 mV 20 Hz to 100 kHz Description For each ac range ac level accuracy is determined by measuring the output of an ac calibrator In addition for the lowest range the output of an audio synthesizer is set to the lowest level of the just completed calibration This level is established as a ratio reference then the signal is attenuated by a precise amount This procedure is run with the ac calibrator connected to the high input and the low input grounded then with the ac calibrator connected to the low input and the high input grounded The output level accuracy and flatness of the Audio Analyzer source are determined by measuring the output of the source directly with the Audio Analyzer s voltmeter which has just been calibrated Voltages up to 300 Vrms will be applied to the Audio Analyzer s input connectors Equipment AC Calibrator HP 745A and HP 746A Datron 4200 or Fluke 5200A and Fluke 5215A Audio Synthesizers repe cee edward aes HP 3336C 4 2 Performance Test 1 Model 8903B Performance Tests Procedure High Level High Input AC Level Accuracy 1 On the Audio Analyzer key in
217. n multiply by 100 The computed result should be within the limits indicated Limits of Computed Results o 95 105 95 105 95 105 95 105 12 For the readings of steps 10 and 11 for each source amplitude setting subtract the readings for each frequency from the reading for 1000 Hz Ignoring the sign the difference should be within the limits given below SOURCE Frequency Hz 20 1 000 20 000 100 000 Output Level Flatness Amplitude V Frequency Hz Actual Maximum 20 20 000 50 000 100 000 20 20 000 50 000 100 000 20 20 000 50 000 100 000 20 20 000 100 000 Performance Test 1 4 11 Performance Tests Model 8903B Performance Test 2 DC LEVEL ACCURACY PERFORMANCE TEST Specification MEASUREMENT DC LEVEL Accuracy 1 of reading 600 mV to 300V z6 mV 600 mV Description The output from a dc standard is applied to the input of the Audio Analyzer and the voltage on the display is compared against the output from the standard This procedure is run with the dc standard connected to the high input and the low input grounded then with the dc standard connected to the low input and the high input grounded Voltages up to 300 Vdc will be applied to the Audio Analyzer s input connectors Equipment DC Standard 4 vote Rb DEOR Ke qe Schein HP 740B Datron 4000 or Fluke 893AR Procedure High Input DC Level Accuracy 1 On the Audio Analyzer key
218. nals power cord or supplied power cord set Whenever it is likely that this protection has been impaired the product must be made inoperative and be secured against any unintended operation If this instrument is to be energized via an external autotransformer make sure the autotransformer s common terminal is connected to the earthed pole of the power source Line Voltage and Fuse Selection CAUTION BEFORE PLUGGING THIS INSTRUMENT into the Mains line voltage be sure the correct voltage and fuse have been selected Verify that the line voltage selection card and the fuse are matched to the power source Refer to Figure 2 1 Line Voltage and Fuse Selection Fast blow fuses may be ordered under HP part numbers 2110 0043 1 5A for 100 120 Vac operation and 2110 0001 1 0A for 220 240 Vac operation Power Cables BEFORE CONNECTING THIS INSTRUMENT the protective earth terminals of this instrument must be connected to the protective conductor of the Mains power cord The Mains plug shall only be inserted in a socket outlet provided with a protective earth contact The protective action must not be negated by the use of an extension cord power cable without a protective conductor grounding This instrument is equipped with a three wire power cable When connected to an appropriate ac power receptacle this cable grounds the instrument cabinet The type of power cable plug shipped with each instrument depends on the country of des
219. nces and selection of Special Functions OPERATING INFORMATION pullout cards are quick operating references that list Special Function HP IB and error codes FREQ AMPTD ADJUST keys change the source frequency or amplitude in specified increments The x10 and 10 keys modify the specified increment SWEEP key initiates or restarts a logarithmic sweep between the START and STOP FREQ settings PLOT LIMIT key displays or initiates entry of plotter limits LINE switch applies power to the Audio Analyzer when set to ON FLOAT switch provides floating output when required SOURCE OUTPUT provide 0 6 mV to 6V open circuit 20 Hz to 100 kHz signal IMPEDANCE light indicates 500 source output impedance if lit 6000 when off Operation SIMPLIFIED OPERATION SOURCE FREQUENCY AND AMPLITUDE Frequency To set source frequency to 500 Hz es 8 Amplitude To set source amplitude to 3V se or 3 Frequency Increment To set frequency increment step to 10 Hz 88 C 8 Amplitude Increment To set amplitude increment step to 200 mV 9 3 8 S Stepping increments To step frequency up 10 Hz as set above press s holding lt down causes frequency to move up slowly in 10 Hz steps MEASUREMENT For ac level SINAD or distortion measurements AC LEVEL SINAD DISTN ress re or ee or Fen p e e e For dc level signal to noise or distortion level me
220. nd 1040 Hz the frequency the source is set to during power up The right display should show between 0 960 and 1 040V The oscilloscope should show a 1 kHz 1 ms period sine wave of approximately 7 Vpp 7 Press RATIO The RATIO key light should light The right display should show 100 3 12 Basic Functional Checks rev 040C T88 Model 8903B 10 11 12 13 14 15 16 Operation NOTE In this and the following steps the displays may vary a few least significant digits Key in 5 2 SPCL to measure ac level with the average responding detector The SPCL key light should remain lit The right display should remain at approximately 100 Key in 5 0 SPCL to measure ac level again with the rms responding detector Set impedance by 6000 by keying in 47 0 then pressing the SPCL button The SPCL key light should The right display should drop by approximately 0 6 down to approximately 99 4 Set the impedance back to 500 by keying in 47 1 then pressing the SPCL button Set the OUTPUT FLOAT switch to FLOAT Move the cable from the HIGH OUTPUT to the LOW OUTPUT Short out the HIGH OUTPUT connector inner conductor to outer conductor The right display should show approximately 9596 Remove the short from the HIGH OUTPUT reconnect the HIGH INPUT to the HIGH OUTPUT and set the OUTPUT switch to the ground position Move the cable from the HIGH INPUT to the LOW INPUT Set the INPUT switch to FLOAT The ri
221. ngs are changed by the transition from remote to local but all measurements are made in a free run mode n DC LLLI ll x d eg es ee Model 8903B m Operation When the Audio Analyzer goes to local mode the front panel REMOTE annunciator turns off However when the Audio Analyzer is being addressed whether in remote or local its front panel ADDRESSED annunciator lights If the Audio Analyzer is not in local lockout mode pressing the front panel LCL local key might interrupt a Data message being sent to the instrument leaving the instrument in a state unknown to the controller This can be prevented by disabling the Audio Analyzer s front panel keys entirely using the Local Lockout message Receiving the Local Lockout Message The Local Lockout message is the means by which the controller sends the Local Lockout LLO bus command If in remote the Audio Analyzer responds to the Local Lockout Message by disabling the front panel LCL local and CLEAR keys In remote CLEAR initiates a Trigger with Settling cycle The local lockout mode prevents loss of data or system control due to someone accidentally pressing front panel keys If while in local the Audio Analyzer is enabled to remote that is REN is set true and it receives the Local Lockout Message it will switch to remote mode with local lockout the first time it is addressed to listen When in local lockout the Audio Analyzer can be returned to local only
222. nion 1973 pp 87 91 CCITT Recommendation P53 See the International Redio Consultative Committee CCIR Recommendations and Reports of the CCIR 1978 Vol X pp 162 163 CCIR recommendation 409 3 Performance Test 6 4 2 Performance Tests Model 8903B Characteristic Performance Limits C Message Weighting Filter Option 013 or 053 Deviation from ideal Response CCIR ARM Weighting Filter Option 014 or 054 Deviation from Ideal Response A Weighting Filter Option 015 or 055 Deviation from Ideal Response See the Bell System Technical Reference 41009 May 1975 2 0 dB 1 4 dB 11 0 dB 0 85 dB 0 7 dB 0 55 dB 0 5 dB 0 2 dB 0 4 dB 0 6 dB 0 8 dB 1 2 dB 1 65 dB 2 0 dB 2 8 infdB 2 5 dB 2 0 dB 1 5 dB 1 0 dB 1 5 2 0dB 1 5 3 0dB 2 0 4 0dB 3 0 6 0dB 3 0 infdB 4 See Dolby Laboratories Inc Engineering Field Bulletin No 19 4 5 See the American National Standard Specification for Sound Level Meters 1971 pp 8 10 American National Standard S1 4 1971 Description 60 Hz to 300 Hz 300 Hz to 3 kHz at 1 kHz 3 kHz to 3 5 kHz 3 5 kHz to 5 kHz 31 5 Hz to 63 Hz 63 Hz to 100 Hz 100 Hz to 200 Hz 200 Hz to 400 Hz 400 Hz to 800 Hz 800 Hz to 1 kHz 1 kHz to 6 3 kHz 6 3 kHz to 8 kHz 8 kHz to 9 kHz 9 kHz to 10 kHz 10 kHz to 12 5 kHz 12 5 kHz to 14 kHz 16 kHz to 20 kHz 20 kHz to 31 5 kHz at 31 5 kHz 20 Hz to 25 Hz 25 Hz to
223. nput is fully balanced it can reject signals which are common to the HIGH and LOW inputs with the INPUT FLOAT switch in the FLOAT position However for valid measurement results there are limitations to the maximum level of common mode signals QVER VOLTAGE PROTECTION HIGH INPUT DIFFERENTIAL TO ATTENUATOR SINGLE ENDED CONVERTER TO PROGRAMMABLE GAIN AMPLIFIER OVER VOLTAGE RANGING PROTECTION DETECTOR LON INPUT ATTENUATOR Analyzer Input Block Diagram Common mode signal limitations exist because the instrument s ranging detector which determines the input voltage range is designed to read only the differential signal between the high and low inputs Thus the instrument can set an incorrect input range if a large common mode signal is present Erroneous measurements may be obtained as a result The block diagram above illustrates that the ranging detector senses the voltage difference between the HIGH and LOW input lines Common mode signals are ignored by the ranging detector while differential signals are measured The block diagram also illustrates that the HIGH and LOW input lines have over voltage protection circuits that open when the input voltage differential or combined common mode and differential exceeds 300V EXAMPLE If a common mode signal of 10V is on the analyzer s inputs with a 1V differential signal the ranging detector selects the 1 19V range The signal that is present on each input is actu
224. nted at the MONITOR output RELATED SECTIONS AC Level DC Level Distortion Distortion Level Input Level Range DC Level Input Level Range Except DC Level Signal to Noise SINAD Special Functions 3 92 Monitor Model 8903B Operation Notch Tune Special Function 6 DESCRIPTION In distortion and distortion level modes the Audio Analyzer automatically tunes the notch filter to the input frequency In the SINAD mode the notch filter is tuned to the frequency of the internal source However by means of keyboard entry using the SPCL key the notch filter can be held to the current notch filter frequency setting PROCEDURE freeze the notch filter enter Special Function code 6 1 then press the SPCL key To return to the automatic tuning mode press the AUTOMATIC OPERATION key or key in the Special Function code 6 0 then press the SPCL key Hitch Tine Special Function Program Code Code Automatic Notch Tuning 6 0SPCL 6 0SP or NO Hold Notch Tuning 6 1SPCL 6 1SP or N1 EXAMPLE To freeze the notch filter Code Function LOCAL SPCL keystrokes a EB x 6 1SP program codes TN L Function PROGRAM CODE x The above procedure gives the HP IB codes for special functions 6 0 and 6 1 Notch Tuning may also be controlled over HP IB with the commands NO and N1 INDICATIONS As
225. o Analyzer will output one byte the status byte each measurement cycle Setting all switches to 1 defeats HP IB operation 5 Reinstall the top cover by reversing the procedure in step c above 6 Connect the line Mains power cable to the Line Power Module and reconnect the HP IB cable to the HP IB connector 7 To confirm the setting refer to HP IB Address in the Detailed Operating Instructions in Section 3 of this manual Interconnections Interconnection data for the Hewlett Packard Interface Bus is provided in Figure 2 4 Mating Connectors Interface Connector The HP IB mating connector is shown in Figure 2 4 Note that two securing Screws are metric Coaxial Connectors Coaxial mating connectors used with the Audio Analyzer should be the 500 BNC male connectors 2 9 Installation Model 8903B Figure 2 3 HP IB Address Switch Shown as Set by the Factory The Address Shown is 11100 in Binary with Both Talk Only and Listen Only Off 2 4 OPERATING ENVIRONMENT The operating environment should be within the following limitations IGHIDOrat Ute ba ud na qned catu eed e ed S pu 0 to 55 Hamidi Soa ste aue ases da baratas us sae ibas qud Pads lt 95 relative PGA iis sched eee ee eee lt 4570 meters 15 000 feet Bench Operation The instrument cabinet has plastic feet and foldaway tilt stands for convenience in b
226. o 2922A and all Major changes that apply to your instrument rev 20JUN91 For additional important information about serial numbers refer to INSTRUMENTS COVERED BY THIS MANUAL in Section 1 Fourth Edition This material may be reproduced by or for the U S Government pursuant to the Copyright License un der the clause at DFARS 52 227 7013 APR 1988 Copyright OHEWLETT PACKARD COMPANY 1985 EAST 24001 MISSION AVENUE TAF C 34 SPOKANE WASHINGTON U S A 99220 Operation and Calibration Manual HP Part 08903 90079 Other Documents Available Service Manual Volume 1 2 HP Part 08903 90062 Microfiche Operation and Service Manual HP Part 08903 90080 Printed in U S A November 1989 U HEWLETT PACKARD 1 Regulatory Information Updated March 1999 Regulatory Information Updated March 1999 Safety Considerations GENERAL This product and related documentation must be reviewed for familiarization with safety markings and instructions before operation This product has been designed and tested in accordance with Publication 1010 Safety Requirements for Electronic Measuring Apparatus and has been supplied in a safe condition This instruction documentation contains information and warnings which must be followed by the user to ensure safe operation and to maintain the product in a safe condition SAFETY EARTH GROUND uninterruptible safety earth ground must be provided from the main power source to t
227. o Analyzer and all related documentation must be reviewed for familiarization with safety markings and instructions before operation Refer to the Safety Considerations page found at the beginning of this manual for a summary of the safety information Safety information pertinent to the task at hand installation performance testing adjustment or service is found throughout the manual 1 4 INSTRUMENTS COVERED BY MANUAL Serial Numbers This instrument has a two part serial number in the form 0000400000 which is stamped on the serial number plate attached to the rear of the instrument The first four digits and the letter constitute the serial number prefix and the last five digits form the suffix The prefix is the same for all identical instruments It changes only when a change is made to the instrument The suffix however is assigned sequentially and is different for each instrument The contents of this manual apply directly to instruments having the same serial prefix es as listed under SERIAL NUMBERS on the title page Options Electrical Option 001 internal plug in filter options and various mechanical options are documented in this manual The differences are noted under the appropriate paragraph such as Options in Section 1 the Replaceable Parts List and the schematic diagrams 1 5 MANUAL UPDATES 1 2 instrument manufactured after the printing of this manual may have a serial prefix that is not listed on the title page
228. o select the Quasi peak Detector press 5 7 SPCL for quasi peak detection Special Function Program Code Detector Code ux rms 5 0 SPCL AO or 5 0SP average 5 2 SPCL A1 or 5 28P quasi peak 5 7 SPCL 5 7SP EXAMPLE PROGRAM CODES AO is the HP IB code for RMS Detector A1 is the HP IB code for Average Detector The Quasi peak Detector HP IB program code is 5 7 SP INDICATIONS When 5 0 SPCL is entered there is no change in the instrument display since rms detection is the default at power up When 5 1 SPCL is entered the SPCL key light is lit to indicate a special function has been selected slow rms detection When 5 2 SPCL fast average detection 5 3 SPCL slow rms detection or 5 7 SPCL quasi peak detection is entered the SPCL key light is lit to indicate a special function has been selected MEASUREMENT TECHNIQUE When measuring complex waveforms or noise a true rms detector will provide a more accurate measurement result than an average responding detector that has been calibrated to indicate the rms value For a sine wave both the true rms and the average responding detectors give correct rms readings However when the signal is a complex waveform or when significant noise is present the average responding detector reading can be in error The amount of error depends upon the particular signal being measured For noise an average responding detector reads low The Quasi peak Detector which has a fast r
229. of an audio synthesizer is measured at various levels with the Audio Analyzer s counter After verification of the counter accuracy the frequency of the internal audio source is then verified by the counter Equipment Audio Synthesizer ioo uae DE EN eaa aden o ea a adis s Nod e HP 3336C NOTE The audio synthesizer s time base accuracy must be 4 ppm or better Procedure 1 On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Set the INPUT and OUTPUT switches to ground Set AMPTD to 1V and set the 80 kHz LOW PASS FILTER off 2 Connect the audio synthesizer s output to the Audio Analyzer s HIGH INPUT 3 Set the audio synthesizer frequency and level open circuit as indicated below For each setting the Audio Analyzer s left display should agree with the frequency setting of the synthesizer to within the limits indicated If needed the synthesizer level can be checked with the Audio Analyzer in its ac level mode Performance Test 5 4 19 Performance Tests Model 8903B Frequency Limits Hz Audio Synthesizer Frequency MEASUREMENT Minimum Actual Maximum 20 AC LEVEL 19 99 20 01 20 DISTN 19 99 20 01 99 900 DISTN 99 895 99 905 99 900 AC LEVEL 99 895 99 905 150 000 AC LEVEL 149 980 150 020 4 Connect the HIGH OUTPUT to the HIGH INPUT in place of the audio synthesizer 5 Key the SOURCE frequencies into the Audio Synthesi
230. operation AUTOMATIC OPERATION LOCAL keystrokes m NT program codes Function PROGRAM CODE ED AU is the HP IB code for AUTOMATIC OPERATION INDICATIONS When the key is pressed the right display blanks and then shows four dashes When the key is released the display is dependent upon the current measurement mode and input COMMENTS If the Audio Analyzer is in the 10 0 Special Function Display Source Settings the instrument returns to the ac level measurement mode The converse of the automatic operation mode is the Hold Settings Special Function prefixed 9 Refer to Hold Settings For information on which specific Special Functions are turned off by the AUTOMATIC OPERATION key refer to Special Functions Since AUTOMATIC OPERATION affects Special Functions it is a good practice to place the AU code at the beginning of a program string when programming the instrument RELATED SECTIONS Display Source Settings Hold Settings Special Functions 3 46 Automatic Operation SS 1 Mn ee ee Model 8903B Operation Common Mode DESCRIPTION Common mode rejection ratio or common mode as it is usually referred to is a measure of the ability of an amplifier to reject signals that are common to both amplifier inputs while allowing the differential signal which may or may not be the weaker signal to be amplified and passed on to the measurement circuitry Since the analyzer i
231. or 50 V The higher of 80 dB or 15 uV The higher of 70 dB or 38 V The higher of 65 dB or 38 V The higher of 80 dB or 15 uV The higher of 70 dB or 45 pV The higher of 65 dB or 45 uV Source and analyzer combined 20 Hz to 20 kHz 80 kHz bandwidth 20 Hz to 50 kHz 500 kHz bandwidth 50 kHz to 100 kHz 500 kHz bandwidth 80 kHz bandwidth 500 kHz bandwidth 20 Hz to 20 kHz 80 kHz bandwidth 20 Hz to 50 kHz 500 kHz bandwidth 50 kHz to 100 kHz 500 kHz bandwidth 20 Hz to 20 kHz 80 kHz bandwidth 20 Hz to 50 kHz 500 kHz bandwidth 50 kHz to 100 kHz 500 kHz bandwidth The output of the Audio Analyzer is connected to its input and the combination of distortion and noise is measured at various frequencies and levels The test measures the distortion and noise of the instrument as a system that is of the source and analyzer combined but compares performance to the individual specifications which are tighter If either the source or the analyzer is out of specification a known good source or analyzer can be substituted to determine which part of the instrument is not within specification Equipment Feedthrough Termination 502 Procedure e atv 9 9 9 9 9 9 9 FF G MR PE 11048 1 Key in 41 0 SPCL to initialize the instrument Set the INPUT and OUTPUT switches both to ground Key in 47 1 SPCL to set the Source impedance to 500 Connect
232. ource frequency changes in discrete steps rather than in a continuous analog manner The number of frequency points in a sweep is determined by the sweep width the ratio of the entered stop and start frequencies and the sweep resolution selected The maximum number of points allowable in one sweep is 255 For more information about the number of points in a sweep and sweep resolution refer to Sweep Resolution Using the sweep feature in conjunction with one of the Audio Analyzer measurement modes provides swept measurement capability Swept response measurement can be plotted by connecting an X Y recorder to the Audio Analyzer recorder x and y axis outputs which are located on the rear panel Any measurement result can be plotted as the source is swept in frequency PROCEDURE Sweep Range Selection The START FREQ and the STOP FREQ keys are used to set the starting and stopping points of the frequency sweep To select a start frequency press the START FREQ key then the appropriate numeric data and unit keys To select a stop frequency press the STOP FREQ key then the appropriate numeric data and unit keys To display the currently programmed start or stop frequency press and hold the respective START FREQ or STOP FREQ key Sweep Mode Selection The SWEEP key puts the instrument in the sweep mode The source does not start sweeping until a signal is sensed at the INPUT At the end of the sweep the sweep circuitry is turned off no longer in sweep
233. output data In certain applications the controller must perform other tasks while controlling the Audio Analyzer Figure 3 7 illustrates a flow chart for developing device subroutines using the instrument s ability to issue the Require Service message when data is ready This subroutine structure frees the controller to process other routines until the Audio Analyzer is ready with data Sending the Status Byte Message The Status Byte message consists of one 8 bit byte in which 3 of the bits are set according to the enabled conditions described above under Sending the Require Service Message If one or more of the three conditions previously described are both enabled and present all the bits corresponding to the conditions and also bit 7 the RQS bit will be set true and the Require Service message is sent If one of the above conditions occurs but has not been enabled by Special Function 22 neither the bit corresponding to the condition nor the RQS bit will be set and the Require Service message will not be sent The bit pattern of the Status Byte is shown in the table labeled STATUS Byte under paragraph 3 7 HP IB Syntax and Characteristics Summary on the following pages Once the Audio Analyzer receives the serial poll enable bus command SPE it is no longer allowed to alter the Status Byte When addressed to talk following SPE the Audio Analyzer sends the Status Byte message NOTE Since the Audio Analyzer cannot alter the S
234. performing the Basic Functional Checks The procedures check all of the applicable bus messages summarized in Table 3 3 8 8 NENNEN CE E Operation Model 8903B Operator s Maintenance For continued protection against fire hazard replace the line fuse with a 250V fast blow fuse of the same rating only Do not use repaired fuses or short circuited fuseholders The only maintenance the operator should normally perform is the replacement of the primary power fuse located within the Line Power Module A14 For instructions on how to change the fuse refer to Figure 2 1 steps 1 and 3 Fuses may be ordered by looking up the reference designator F1 in Section 6 Replaceable Parts and ordering the correct part number for 100 120 Vac or for 220 240 Vac operation both fuses are 250V fast blow NOTE If the instrument does not operate properly and is being returned to Hewlett Packard for service please complete one of the blue repair tags located at the end of this manual and attach it to the instrument Refer to Paragraph 2 7 in Section 2 for packaging instructions 3 4 Model 8903B Operation Table 3 1 Operating Characteristics Summary Operating Parameter Capabilities Frequency 20 Hz to 100 kHz Level 0 6 mV to 6V open circuit Impedance 500 or 600 selectable floating output can be selected Output Limits Frequency 20 Hz to 100 kHz 150 kHz ac level Level 0 to 300V a
235. plot limit would correspond to 20 dB RELATED SECTIONS RATIO and LOG LIN X Y Recording Plot Limit 3 99 Operation Model 8903B Post Notch Detector Filtering Except SINAD Special Function 5 DESCRIPTION The Audio Analyzer normally makes audio measurements using a fast responding detector By means of keyboard entry using the SPCL key additional low pass filtering can be added after the post notch detector The additional low pass filtering slow detector is useful in stabilizing measurements on unstable or noisy signals or whenever display jitter is considered excessive PROCEDURE To change the Audio Analyzer post notch filtering response from fast to slow or vice versa enter the corresponding Special Function code then press the SPCL key Post Notch Special Function Program Code Detector Response Code Fast RMS Detector 5 0 SPCL Slow RMS Detector 5 1 SPCL Fast AVG Detector 5 2 SPCL Slow AVG Detector 5 3 SPCL EXAMPLE To enter a slow rms detector response mode Code n Functions LOCAL SPCL keystrokes 5j C EB B program codes Function PROGRAM CODE x For HP IB codes refer to the Procedure above INDICATIONS As the numeric code is entered it will appear on the left display When the SPCL key is pressed the display returns to show the input signal frequency When Special Function code 5 1 5 2 or 5 3 is entered and the SPCL key is pressed the LED w
236. r of ten multiplier Refer to Rapid Frequency Count in the Detailed Operation Instructions for the only exceptions to this format The string is terminated by a carriage return CR and a line feed LF string positions 11 and 12 Data is always output in fundamental units for example Hz volts dB etc and the decimal point not sent is assumed to be to the right of the fifth digit of the mantissa Data values never exceed 4 000 000 000 Data Output Format DDDDDESNNCRLF Signed Mantissa Line Feed Indicates Exponent Follows Carriage Return Exponent Sign Exponent Magnitude NOTE For the only exception to the above format refer to Rapid Frequency Count in the Detailed Operating Instructions When an error is output to the bus it follows the same twelve byte format described above except most of the numeric digits have predetermined values as shown below Error outputs always exceed 9 000 000 000 The two digit error code is represented by the last two digits of the five digit mantissa The error code can be derived from the string by subtracting 9 x 10 then dividing the results by 100 000 Error Output Format 900DDE 05CRLF Line Feed Error Code Carriage Return Receiving the Clear Message The Audio Analyzer responds to the Clear message by assuming the settings detailed in Table 3 5 The Audio Analyzer responds equally to the Selected Device Clear SDC bus command when addressed to listen and the Device Clear DCL bus co
237. rding Sweep Resolution 3 135 SS SS SS SS a OH C Operation Model 8903B Time Between Measurements Special Function 14 DESCRIPTION A one second delay between measurements can be added using Special Function 14 This one second delay is normally used when making plots with a relatively slow X Y recorder It can also be used to allow the device under test to settle before making the measurement PROCEDURE To add or delete the one second time delay between measurements key in the corresponding Special Function code and then press the SPCL key Time Delay Between Special Program Code Measurements Function Code x Minimum 14 0 SPCL 14 0SP Add 1 second 14 1 SPCL 14 1SP EXAMPLE To set a one second time delay between measurements Function LOCAL keystrokes 3 a n x program codes PROGRAM CODES um For HP IB codes refer to Procedure above INDICATIONS As the numeric code is entered both displays will blank and the entered code will appear in the left display When the SPCL key is pressed the SPCL key lights if it is not already on If it is on it will remain on Both displays then return to the display that is appropriate for the currently selected measurement mode RELATED SECTIONS Automatic Operation Special Functions X Y Recording 3 136 Time Between Measurements Model 8908 Operation X Y Recording DESCRIPTION
238. required to remove the error causing condition are given Additional information pertaining to particular errors is also given Message Action Required Comments Operating Errors Reading too large for display Calculated value out of range Notch cannot tune to input Input level exceeds instrument specifications This error code indicates that although the required calculation is within the capability of the instrument the result of the calculation exceeds the display capabilities Enter new RATIO reference Refer to RATIO and LOG LIN Adjust input frequency to within specified limits Refer to Table 1 1 This error code indicates that the input overload detector has tripped not in range hold This could be caused by too large an ac signal or too much ac on a dc signal NOTE Although error codes 17 18 and 19 are officially listed here under Operating Errors they should be considered rather as diagnostic indications Error Message Summary 3 65 Operation Error Messages cont d Model 8903B Operating Errors Cont d This error code indicates that the counter has failed to return a value This can only be caused by a malfunction in the counter Refer to Service Sheet 14 This error code indicates a malfunction in the counter and or the oscillator Refer to Service Manual Internal voltmeter cannot make measurement Source cannot tune as requested
239. rn First Measurement lt 1 5s typical Measurement Rate 3 reading s FREQUENCY MEASUREMENT Measurement Rate same as measurement mode se lected Counting Technique reciprocal with 2 MHz time base AUDIO FILTERS 400 Hz High Pass Filter Rejection gt 40 dB at 240 Hz gt 65 dB at 60 Hz REAR PANEL INPUTS AND OUTPUTS Recorder Outputs X Axis 0 to 10 Vde corresponding to the log of the os cillator frequency Output Resistance 1k Y Axis 0 to 10 Vdc corresponding to the displayed value and entered plot limits Output Resistance 1 Pen Lift TTL output Monitor Output Output Impedance 6002 In ac level mode provides scaled output of measured input signal In SINAD distortion and distortion level modes pro vides scaled output of input signal with the fundamental removed The meter has hysteresis The trip point for the 24 dB range is gt 18 dB and the trip pont for the 18 dB range is lt 17 dB rev 30DEC88 Model 8903B General Information Tuble 1 3 Recommended Test Equipment Critical Specifications Suggested Model AC Calibrator Accuracy 0 5 7 mV to 300V 20 Hz to 100 kHz HP 745A and Flatness 0 1 20 Hz to 100 kHz lt 6V HP 746A Output Current 60 mA Datron 4200 or Frequency Accuracy 5 Fluke 5200A and Fluke 5215A Audio Synthesizer Frequency Range 20 Hz to 500 kHz HP 3336C Frequency Accuracy 4ppm Output Range 0 6 Vrms into 500 Output Attenuatio
240. rn on a specific filter has no effect that is the filters cannot be toggled on and off using the same HP IB command The individual filter characteristics are given in Table 1 1 Specifications and in Table 1 2 Supplemental Information The optional weighting bandpass plug in filter assemblies weights the frequency response of the Audio Analyzer as shown in their respective curve plots Filters 3 69 Operation Model 8903B RESPONSE 4B on d o TP at igs He at rT AHHH A T 1 IL T EN INCI Filter Fd d TEE aL PEN RESPONSE dB 1 kHz 100 kHz FREQUENCY Hz CCIR and CCIR ARM Weighting Filter Plot 3 70 Filters Model 8903B ao ul 2 ue uJ a a Oe es AE ME a ATN PME gt ac a M SOE A OD Temesa WT Tt Weighting VlA do LI 4 LEE d LY LL g l d 1 kHz 100 kHz FREQUENCY Hz A Weighting and C Message Weighting Filter Plot RELATED SECTIONS AC Level Distortion Distortion Level Signal to Noise SINAD Filters Operation 3 71 NEM E c 2 Operation Model 8903B
241. s P Performance Tests A Adjustments T Troubleshooting rev 30DEC88 1 23 General Information Model 8903B Digital Test Extender Board Extender Board 44 contacts 2 x 22 3 required HP 08901 60084 Extender Board 30 contacts 2 x 15 2 required HP 08901 60085 Conductive polyurethane foam 12 x 12 x 0 25 inches nonmagnetic HP 4208 0094 Refer to Section 8 paragraph 8 11 of this manual for application Tabie 1 4 Service ccessories HP 08903 60018 No substitution recommended NOTE The performance tests adjustments and troubleshooting procedures are based on the assumption that the recommended test equipment is used Substituting alternate test equipment may require modification of some procedures 1 24 rev 30DECS88 Model 8903B Installation Section 2 INSTALLATION 2 1 INTRODUCTION This section provides the information needed to install the Audio Analyzer Included is information pertinent to initial inspection power requirements line voltage and fuse selection power cables inter connection mating connectors operating environment instrument mounting storage and shipment In addition this section also contains the procedure for setting the internal HP IB talk and listen address switches 2 2 INITIAL INSPECTION To avoid hazardous electrical shock do not perform electrical tests when there are signs of shipping damage to any portion of the outer enclosure covers
242. s a Bode magnitude plot if dB is used MM S c B x Lo a E NNNM NN Model 8903B General Information Frequency Another common and basic measurement is frequency With an oscilloscope you simply determine the time interval between like points on the repetitive waveform and take the reciprocal With a frequency counter frequency is measured electronically and displayed The measurement is easier and usually much more accurate than could be made visually with an oscilloscope The Audio Analyzer contains a counter which displays the frequency of the input signal for all ac measurements It should be noted that the counter is a reciprocal type it measures the period of the signal as you do with an oscilloscope and computes the reciprocal to obtain the frequency The advantage of this technique is that for low audio frequencies higher resolution is obtained in a shorter measurement time DC Level Although not part of an audio signal dc level is a quantity often encountered in audio equipment for example bias voltages and outputs from ac to dc converters Sometimes plots of dc level vs frequency are desired as in the case of an ac to dc converter The Audio Analyzer has dc level as one of its measurement modes Signal impurities Distortion SINAD and signal to noise ratio are used to describe the impurity content of a signal These terms are somewhat related and can often be confused A pure signal is defined as a perf
243. s setting refer to the discussion titled HP IB Address in the Detailed Operating Instructions near the end of this section 3 23 a gt Model 8903B Table 3 3 Message Reference Table 1 of 2 Related Commands HP IB Message Applicable Response and Controls All Audio Analyzer operations except the LINE switch FLOAT switch and the 10 and x10 functions are Yes bus programmable All measurement results special displays and error outputs except the display are available to the Remote Yes Remote mode is enabled when the REN bus control line is true However remote mode is not entered until the first time the Audio Analyzer is addressed to listen The front panel REMOTE annunciator lights when the instrument is actually in the remote mode When entering remote mode no instrument settings or functions are changed but all front panel keys except LCL and CLEAR are disabled and entries in progress are cleared Interface Functions bus If in remote and addressed to listen the Audio Analyzer GET DT1 makes a settled measurement according to previously programmed setup It responds equally to bus command GET and program code T3 Trigger with Settling a Data message Sets SOURCE to 1 kHz and 0 mV MEASUREMENT to AC LEVEL with the 80 kHz LP FILTER on and sets the trigger mode to free run Resets many additional parameters as shown in Table 3 5 Clears Status Byte RQS bit Require Servic
244. s to be displayed in or dB relative to a reference 13 LOG LIN key causes results to be displayed in logarithmic or linear units 3 6 Model 8903B 14 15 16 17 18 18 20 21 22 23 24 20 26 27 28 29 30 31 Operation MEASUREMENT keys command the Audio Analyzer to make and display the selected measure ment SINAD meter is marked for EJA and CEPT sensitivity and selectivity readings when within limits INPUT couples measurement signal into the instrument FLOAT switch provides floating input when required LOW PASS 30 kHz and 80 kHz filters reject high frequency noise RIGHT MOST OPTIONAL PLUG IN FILTER key selects the filter that is installed in the right most filter slot The CCITT WEIGHTING band pass FILTER Option 051 weights receiver testing according to CCITT recommendation P53 LEFT MOST OPTIONAL PLUG IN FILTER key selects the filter installed in the left most filter slot The 400 Hz HIGH PASS filter option 010 rejects line related noise and squelch tones SPCL key completes entry of Special Function codes for accessing instrument operations additional to those having dedicated front panel keys Also permits reading of Special Function or hardware status CLEAR key erases keyboard entries in progress In remote hold CLEAR initiates a Trigger with Settling measurement cycle Numeric keys are used for manual entry of frequency amplitude limits RATIO refere
245. scilloscope gives only a rough indication of the amount of distortion present on a signal general rule of thumb is that if the non linearity causing the distortion is gentle for example not clipped a trained eye can discern distortion as low a 5 on an oscilloscope display Figure 1 6 shows several examples of waveforms with 5 THD and the components that combined to produce them 5 distortion would be considered quite high in a quality hi fi amplifier An audio spectrum analyzer which allows the user to see the magnitude of all harmonics is perhaps the best instrument to measure harmonic distortion The audio spectrum analyzer method however requires a fairly expensive instrument and some mathematical manipulation 1 13 General Information Model 8903B uy Ay Y SIN X AND 0 05 SIN 2X SIN X AND 0 05 COS 2X SIN X 0 05 SIN 2X SIN X 0 05 COS 2X V V SIN X AND 0 05 SIN 3X SIN X AND 0 05 COS 3X ave j SIN X 0 05 SIN 3X SIN X 0 05 COS 3X Figure 1 6 Several Waveforms Each With 5 THD and the Signal Components Which Produced Them The traditional method of measuring distortion accepted by the Institute of High Fidelity and others is with a distortion analyzer The method is simple and adequate for most situations With a distortion analyzer you simply measure the signal level and set it up as a reference then you insert a notch filter tuned to the frequency of the fundamental and measure the outp
246. sembly A6 Output Attenuator Assembly A7 Latch Assembly A8 Controller Counter Assembly A9 Remote Interface Assembly A10 Remote Interface Connector Assembly A11 Series Regulator Socket Assembly A12 Connector Filter Assembly A13 Power Supply and Motherboard Assembly A14 Line Power Module Basic functional Checks Power Up Checks P Paragraph PT Performance Test ADJ Adiustment rev 15MAYS88 5 3 Adjustments Model 8903B Adjustment 1 INTERNAL REFERENCE FREQUENCY ADJUSTMENT Reference Service Sheet 15 Description An oscilloscope triggered by an external reference is used to monitor the internal reference frequency while it is adjusted Equipment PYEQUCHCY Standard E ERE UU IE DELE House Standard OSCILLOSCOPE add Et Erin beUi i E eb ue HP 1740A EXTERNAL VERTICAL TRIGGER INPUT FREQUENCY STANDARD 8903B AUDIO ANALYZER Figure 5 1 Internal Reference Frequency Adjustment Test Setup Procedure 1 Allow the equipment to warm up for 15 minutes 2 Connect the equipment as shown in Figure 5 1 For instruments with Serial Prefix 2922A and below connect the oscilloscope to ASTP15 For instruments with Serial Prefix 2948A and above connect the oscilloscope to ASTP2 The figure shows the setup for house standard frequencies of 2 MHz or lower If the frequency of the frequency standard is 5
247. set to a specified level on and off and measures the ac level for both conditions This is similar to the experience you have when listening to a recording at a comfortable volume then lifting the tone arm and listening to the level of the residual hiss and hum General Information Model 8903B Internal Source The internal source is used when a low distortion stimulus for the device under test is desired Its distortion is about the same as that of the Audio Analyzer s measurement system The combination permits measurements of distortion as low as 0 003 90 dB Plotting When used in conjunction with the sweep mode any of the measurements vs frequency can be plotted using the rear panel X and Y AXIS outputs and an x y recorder The internal source is used as the stimulus This simplifies traditionally time consuming measurements such as flatness gain distortion and SINAD vs frequency and does not require the use of an external controller although this too can be used via HP IB 1 16 Model 8903B period General Information Tuble 1 1 Specifications 1 of 5 All parameters describe performance in automatic operation or with properly set manual controls with 1 5 hour warmup SYSTEM SPECIFICATIONS ome DISTORTION Residual Distortion and Noise the higher of 80 kHz BW 500 kHz BW SIG NOISE Frequency Range Display Range Accuracy Input Voltage Range Residual Noise the high
248. source to approximately 400 Hz until the right display reads 3 dB The left display should show between 360 and 440 Hz Press the filter key listed in the following tables for the filter options installed in the instrument The respective key light should light For each filter set the source frequency as shown in the table Verify that the level ratio shown in the right display is within the limits shown for each frequency Basic Functional Checks 3 13 Table for CCITT Weighting Filter Option 011 or 051 Oscillator RATIO Frequency Hz Limits dB 12 1 to 9 1 0 4 to 0 4 7 1 to 4 1 11 5 to 5 5 40 0 to 32 0 Table for CCIR Weighting Filter Option 012 or 052 Oscillator RATIO Frequency Hz Limits dB 31 4 to 28 4 14 5 to 13 1 12 0 to 12 4 11 7 to 12 3 7 5 to 87 23 7 to 20 7 Table for C Message Weighting Filter Option 013 or 053 Oscillator RATIO Frequency Hz Limits dB 44 0 to 41 0 9 0 to 6 0 0 2 to 0 2 4 0 to 1 0 30 0 to 27 0 Table for CCIR ARM Weighting Filter Option 014 or 054 Oscillator RATIO Frequency Hz Limits dB 37 0 to 34 0 20 1 to 18 7 6 4 to 46 8 6 1 to 6 7 1 9 to 3 1 29 3 to 26 3 Model 8903B Model 8903B Operation Table for Weighting Filter Option 015 or 055 Oscillator RATIO Frequency Hz Limits dB
249. ssage Description This check determines whether or not the Audio Analyzer properly issues Data messages when addressed to talk This check assumes that the Audio Analyzer is able to handshake and recognize its own address Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON then after the power up sequence is complete press the DISTN key Address the Audio Analyzer to talk and store its red 728 V ENTER 728 V output data in variable V The output is E96 since there is no signal at its INPUT Display the value of V dsp V PRINT V Check that the Audio Analyzer s REMOTE annunciator is off but that its ADDRESSED annunciator is on The controller s display should read 9009600000 00 HPL or 9009600000 BASIC Operation x Model 8903B Receiving the Data Message Description This check determines whether or not the Audio Analyzer properly receives Data messages The Data messages sent also cause the 7 least significant HP IB data lines to be placed in both their true and false states This check assumes the Audio Analyzer is able to handshake recognize its own address and properly make the remote local transitions Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON ee Send the first part of the Remote message rem 7 REMOTE 7 enabling the Audio Analyzer to remote Address the Audio Analyzer to listen completing wrt 728 M2 OUTPUT 728 M2 the Remo
250. st RMS Detector N Detector Slow RMS Detector Y Filtering except Fast Average Detector Y in SINAD Slow Average Detector Y Quasi Peak Detector Y Notch Tune Automatic notch tuning N Hold notch tuning Y SINAD Meter to 18 dB range N Range 0 to 524 dB range Y All errors enabled N Disable Analyzer errors Y Errors 12 17 31 and 96 Disable Source errors Error 18 and 19 Disable both Analyzer and Source errors Y Error Disable Hold Settings Display Source Settings Hold input level ranges post notch gain decimal point and notch tuning at present settings lt Display source settings as entered Frequency in left display amplitude in right display Restore last RATIO reference and enter RATIO mode if allowed Dispiay RATIO reference Re enter Ratio Mode lt lt Signal to Noise Automatic Selection Measurements 200 ms delay Delay 400 ms delay 600 ms delay Continued 800 ms delay on next page 1 0s delay ANE EE lt lt lt N No Not Applicable Y Yes Except the LCL S Shift and Numeric Keys Special Functions 3 125 Operation Special Function Code co em Signal to Noise Cont d X Y Recorder 13 0 13 0SP 13 1 13 1SP 14 0SP Time Between 14 0 Measurements 14 1SP SINAD and 16 0 16 0SP Signal to Noise Dispiay 16 1 Resolution 16 1SP
251. sts are to be considered valid 4 2 EQUIPMENT REQUIRED Equipment required for the performance tests is listed in Table 1 3 Recommended Test Equipment in Section 1 of this manual Any equipment that satisfies the critical specifications in the table may be substituted for the recommended models NOTE The performance tests are based on the assumption that the recommended test equipment is used Substituting alternate test equipment may require modification of some procedures 4 3 TEST RECORD Results of the performance tests may be tabulated on the Test Record shown in Table 4 1 at the end of the procedures The Test Record lists all of the tested specifications and their acceptable limits The results recorded at incoming inspection can be used for comparison in periodic maintenance and troubleshooting and after repairs or adjustments 4 4 CALIBRATION CYCLE This instrument requires periodic verification of performance Depending on the use and environ mental conditions the instrument should be checked using the following performance tests at least once every vear 4 5 ABBREVIATED PERFORMANCE TESTING No abbreviation of performance testing is recommended rev 20 U NUI Performance Tests Model 8903B Performance Test 1 AC LEVEL ACCURACY AND OUTPUT LEVEL ACCURACY AND FLATNESS TEST Specification SOURCE OUTPUT LEVEL Accuracy 2 of setting 60 mV to 6V open circuit 20 Hz to 50 kHz 3 of setting 6 mV to 6V ope
252. t Frequency Right Display ance ae ca tenes eee Seeds Gener vieta eb Input AC Level Source Output Impedance sesasi aod ERES MUS UA V wa REED 6002 Service Request Condition ccccescccces eese ehh n HP IB Code Error Only Status Dybe e dq Lu LER E Su cci Cleared Trisger WOdE teeta dd ep Free Run Code TO ze fp PPP All Special Functions OFF or in their zero suffix ehe oe et ie oett M uu DS E Enable KAXI qe qi cC r EE OV PENTI E bn meae dtc SEI T ME rep TTL high NOTE The two Front Panel FLOAT switches are set manually RELATED SECTIONS RATIO and LOG LIN Service Request Condition 1 See RATIO and LOG LIN Detailed Operation Sections 2 Except Service Request Condition which is set to 22 2 HP IB Code Error 3 52 Default Conditions and Power up Sequence O 1 1 L L Model 8903B Operation Detector Selection DESCRIPTION The Audio Analyzer contains a high accuracy wide band voltmeter with three types of detectors true rms average responding and quasi peak PROCEDURE select the true RMS Detector press 5 0 SPCL for fast rms detection or 5 1 SPCL for slow rms detection To select the Average Detector press 5 2 SPCL for fast average detection or 5 3 SPCL for slow average detection T
253. t is in the sweep mode Note the light does not necessarily mean that the source is sweeping When the sweep is completed the light will turn off COMMENTS The Audio Analyzer powers up with start and stop frequencies of 20 Hz and 20 kHz respectively Reverse sweep that is sweeping from a higher frequency to a lower frequency is obtained by simply entering a start frequency which is higher than the stop frequency During the sweep mode all the front panel keys remain active hence they affect the sweep function Pressing certain front panel keys while the instrument is in the sweep mode can cause an undefined state or an error condition Therefore it is recommended that only the following keys be pressed during a sweep CLEAR STOP FREQ START FREQ AUTOMATIC OPERATION and SWEEP The function of these keys during sweep mode is described below CLEAR and AUTOMATIC OPERATION When pressed the keys stop the sweep The source remains tuned to the frequency point where the sweep was stopped However the sweep cannot be restarted from that point START FREQ and STOP FREQ These keys when pressed stop the current sweep and tune the source to either the currently programmed start or stop frequency Which frequency the source is tuned to depends upon which key was pressed SWEEP The sweep key stops the current sweep retunes the source frequency back to the start frequency and restarts the sweep from that point Sweep 3 131 Operatio
254. t measurements Special Considerations for Triggered Operation When in free run mode the Audio Analyzer must pay attention to all universal bus commands for example serial poll enable SPE local lockout LLO etc In addition if it is addressed to listen it must pay attention to all addressed bus commands such as go to local GTL group execute trigger GET etc As a consequence of this the Audio Analyzer must interrupt the current measurement cycle to determine whether any action in response to these commands is necessary Since many elements of the measurements are transitory the measurement must be reinitiated following each interruption Thus if much bus activity occurs while the Audio Analyzer is trying to take a measurement that measurement may never be completed Trigger Immediate and Trigger with Settling provide a way to avoid this problem When the Trigger Immediate T2 and Trigger with Settling T3 codes are received the Audio Analyzer will not allow its measurement to be interrupted indeed even handshake of bus commands are inhibited until the measurement is complete Once the measurement is complete bus commands will be processed as discussed under Trigger Immediate above with no loss of data Thus in an HP IB environment where many bus commands are present Trigger Immediate or Trigger with Settling should be used for failsafe operation 3 29 x Model 8903B 3
255. t normally available from dedicated front panel keys They are intended for the user who has an understanding of the instrument and the service technician who needs arbitrary control of the instrument functions Special Functions are accessed via keyboard or HP IB entry of the appropriate numeric code and terminated by the SPCL key or HP IB code refer to Procedures below The codes comprise a prefix decimal and suffix Special Functions are disabled by a variety of means depending upon the function Refer to the comprehensive listings below for actions which clear or disable any Special Function Special Functions are grouped by their prefixes into three categories as follows Prefix 0 This is the Direct Control Special Function and is intended for use in servicing the Audio Analyzer All instrument error messages and safeguards are inactive This is discussed in detail in Section 8 If the Direct Control is entered inadvertently press AUTOMATIC OPERATION Prefixes 1 to 39 These are the User Special Functions which are used during normal instrument operation when a special configuration a special measurement or special information is required All error messages and some safeguards remain in effect unless the operator disables them T hese Special Functions are described below Prefixes 40 to 99 These are the Service Special Functions used to assist in troubleshooting an instrument fault The functions available are quite diverse spe
256. t panel ADDRESSED annunciator turns on Tuble 3 5 Response to a Clear Message mw _ Start Frequency 20 Hz Stop Frequency 20 kHz Plot Limits Lower 100 0 Upper 100 0 X Y Recorder Enabled Frequency 1000 0 Hz 1000 0 Hz 0 00 mV 0 100V AC Level RMS 80 kHz Low Pass On Frequency increment Amplitude Amplitude Increment Measurement Detection Low Pass LP Filter High Pass HP Bandpass BP Filter SPCL AI off All Special Functions off or set to their zero suffix mode except Service Request Condition set to 22 2 HP IB code error Off Linear refer to RATIO and LOG LIN Detailed Operating instructions Enabled HP IB Code Error Only Cleared Free Run Code TO Cleared Ratio Log Lin Right Display Read Service Request Condition Status Byte Trigger Mode Local Lockout Receiving the Local Message The Local message is the means by which the controller sends the Go To Local GTL bus command If addressed to listen the Audio Analyzer returns to front panel control when it receives the Local message If the instrument was in local lockout when the Local message was received front panel control is returned but lockout is not cleared Unless it receives the Clear Lockout Set Local message the Audio Analyzer will return to local lockout the next time it goes to remote No instrument setti
257. t under certain conditions This should be kept in mind when operating the instrument with error messages disabled RELATED SECTIONS Automatic Operation Error Message Summary Special Functions Error Disable 3 63 MM LA Operation Model 8903B Error Message Summary DESCRIPTION The instrument generates error messages to indicate operating problems incorrect keyboard entries or service related problems The error message is generally cleared when the error condition is removed Error 31 is an exception The Error Messages are grouped by error code as follows Error 10 through Error 39 and Error 90 through Error 99 These are Operating and Entry Errors which indicate that not all conditions have been met to assure a calibrated measurement or that an invalid key sequence or keyboard entry has been made Operating Errors can usually be cleared by using the front panel controls The Error Disable Special Function 8 N can be used to selectively disable certain operating error messages Entry Errors require that a new keyboard entry or function selection be made Error 65 through Error 89 These are Service Errors which provide additional service related information Service Errors must be enabled to appear and do not necessarily represent failures within the instrument Service Errors are discussed in Section 8 Service volumes 2 and 3 HP IB OUTPUT FORMAT x The HP IB output format for errors is shown below 900DDE 05CRLF
258. tage that is read by the internal dc voltmeter and monitored by an external dc voltmeter The sensitivity of the internal dc voltmeter is adjusted so that the amplitude display of the Audio Analyzer agrees with the level measured by the external dc voltmeter The ac at the source s output jack is then monitored by an external ac voltmeter The ac to dc converter is adjusted so that the amplitude display of the Audio Analyzer agrees with the level measured by the external ac voltmeter at two different levels Since there are two ac to dc converters one true rms responding and one average responding two separate adjustments are made Equipment Digital VolUnDetBf orrir sirr oe oO EIS E Derbi qi ir M ael E HP 3455A A4TP1 DC OUT STEP 2 1 INPUT DIGITAL VOLTMETER step 4 Figure 5 4 Voltmeter Adjustment Test Setup Procedure 1 On the Audio Analyzer key in 41 0 SPCL to initialize the instrument Key in 1 11 SPCL to set the input range to 3 00V Key in 3 1 SPCL to set the post notch amplifier gain to 0 dB Set AMPTD to 3V Key in 49 3 SPCL to read the output rms detector voltage directly Set the INPUT and OUTPUT switches both to ground Connect the equipment as shown in Figure 5 4 Connect the voltmeter to A4TP1 DC OUT Set the voltmeter to read dc volts Adjust A4R125 DC CAL for a reading on the right display of the Audio Analyzer that is the same as the reading on the voltmeter within 0 5 mV
259. tatus Byte while in serial poll mode it is not possible to continually request the Status Byte while waiting for a condition to cause a bit to be set After the Status Byte message has been sent it will be cleared if the Serial Poll Disable SPD bus command is received if the Abort message is received or if the Audio Analyzer is unaddressed to talk Regardless of whether or not the Status Byte message has been sent the Status Byte and any Require Service message pending will be cleared if a Clear message is received If the instrument is set to Talk Only the Status Byte is cleared each time the one byte Data message is issued to the bus Sending the Status Bit Message The Audio Analyzer does not respond to a Parallel Poll Enable PPE bus command and thus cannot send the Status Bit Message Receiving the Abort Message The Abort Message is the means by which the controller sets the Interface Clear IFC bus control line true When the Abort message is received the Audio Analyzer becomes unaddressed and stops talking or listening Model 8903B x Operation START 8903B INTERRUPT ON SRQ SET TRIGGER READ STATUS BYTE MODE TO HOLD FROM 8903B HP 1B CODE T1 TO OTHER INSTRUMENT NO SRQ FROM SERVICE ROUTINES 8903B YES CONF I GURE MEASUREMENT TEST OTHER 89038 NO SRQ CONDITIONS TRIGGER MEASUREMENT HP 18 CODE T en 1 READ DATA FROM 89038 ENABLE SRQ ON DATA READY 1 CODE 22 38P 8903B
260. te message then send a Data message selecting the SINAD measurement Check that both the Audio Analyzer s REMOTE and ADDRESSED annunciators are on Check also that its SINAD key light is on Local Lockout and Clear Lockout Set Local Messages Description This check determines whether or not the Audio Analyzer properly receives the Local Lockout message disabling all front panel keys The check also determines whether or not the Clear Lockout Set Local message is properly received and executed by the Audio Analyzer This check assumes that the Audio Analyzer is able to handshake recognize its own address and properly make the remote local transitions Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON ee Send the first part of the Remote message REMOTE 7 enabling the Audio Analyzer to remote Send the Local Lockout message LOCAL LOCKOUT 7 Address the Audio Analyzer to listen completing OUTPUT 728 the Remote message Check that both the Audio Analyzers REMOTE and ADDRESSED annunciators are on Press the Audio Analyzer s LCL key Both its REMOTE and ADDRESSED annunciators should remain on Send the Clear Lockout Set Local message LOCAL 7 Check that the Audio Analyzer s REMOTE annunciator is off but its ADDRESSED annunciator is on Clear Message Description This check determines whether or not the Audio Analyzer properly responds to the Clear message This check assumes that
261. the Audio Analyzer is able to handshake recognize its own address make the remote local changes and receive Data messages Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON Model 8903B Operation Send the first part of the Remote message enabling rem 7 REMOTE 7 the Audio Analyzer to remote Address the Audio Analyzer to listen completing the wrt 728 M2 OUTPUT 728 M2 Remote message then send a Data message that selects the SINAD measurement Check that both the Audio Analyzer s REMOTE and ADDRESSED annunciators are on and that the SIN AD key light is also on Send the Clear message setting the Audio cir 728 RESET 728 Analyzer s measurement to AC LEVEL Check that both the Audio Analyzer s REMOTE and ADDRESSED annunciators are on and that the AC LEVEL key light is on Abort Message Description This check determines whether or not the Audio Analyzer becomes unaddressed when it receives the Abort message This check assumes that the Audio Analyzer is able to handshake recognize its own address make the remote local changes and enter serial poll mode Before beginning this check set the Audio Analyzer s LINE switch to OFF then to ON Send the Remote message to the Audio Analyzer REMOTE 728 Check that both the Audio Analyzer s REMOTE and ADDRESSED annunciators are on Send the Abort message unaddressing the Audio cli 7 ABORTIO 7 Analyzer to listen Check that the Au
262. the X AXIS output is gt 10 3 Vdc at full scale increase the value of A7R10 if the voltage is 9 7 Vdc reduce the value 5 5 POST REPAIR TESTS ADJUSTMENTS AND CHECKS Table 5 2 lists the performance tests adjustments and checks needed to calibrate or verify calibration of a repaired assembly T he tests adjustments and checks are classified by assembly repaired The table is also useful as a cross reference between performance tests and assemblies when the failure is a specification that is slightly out of limits After all repairs perform the Basic Functional Checks paragraph 3 5 and the Internal Reference Frequency Adjustment Adjustment 1 The Basic Functional Checks utilize automatic tuning and measurements which exercise nearly every circuit in the instrument except the Remote Interface Assembly 5 6 RELATED ADJUSTMENTS The procedures in this section can be done in any order but it is advisable to check the time base reference first 5 2 rev 15MAY88 Model 8903B Adjustments Table 5 2 Post Repair Tests Adjustments and Checks Assembly Repaired Test Adjustment or Check Ret Power Up Checks P 8 27 Service Special Functions Use 60 0 SPCL Key Scan and 8 23 exercise all keys AC Level Accuracy and Output Level Accuracy and Flatness Performance Test Check ac level accuracy only DC Level Accuracy Performance Test Distortion and Noise Performance Test Audio Filters Performance Test Common Mode Rejec
263. the numeric data and the unit keys are used to program the output level of the source The source level can be entered in V mV or dBm that is dB relative to 1 milliwatt into a 6000 load equivalent to dBre 0 775V The amplitude entered is the open circuit value The output impedance can be either 6000 or 500 The AMPTD key is also used to display the currently programmed output level The amplitude range is 0 6 mV to 6V The maximum resolution is better than 0 3 PROCEDURE To set the source output level press the AMPTD key and then the appropriate numeric data and unit keys Once the AMPTD key has been pressed new data and unit entries can be made to select different amplitudes until another source function key for example the FREQ key is pressed To display the currently programmed amplitude press and hold the AMPTD key EXAMPLE To set the source output level to 1 5V P x Function fo Data _ _ Unit s LOCAL eod x AP1 5VL Function Unit ata program codes PROGRAM CODE um AP is the program code for the AMPTD key INDICATIONS When the AMPTD key is pressed the right display shows the currently programmed output level As the new output level data is entered it will appear on the left display When the units key is pressed the left display returns to show the input signal frequency When the amplitude is set to the output is set to zero but the oscillator remains on 3 44 Ampl
264. the reading on the right display by the entry in the table of step 4 which corresponds to the ac calibrator setting of 0 007 Vrms at the current frequency Divide the result by 5 01 The computed ratio should be within the limits indicated below For example if the reading in step b was 5 0396 and the corresponding reading of step 4 is 101 596 the computed result is 5 0396 x 101 596 101 501 4 8 Performance Test 1 Model 8903B Performance Tests Displayed Reading of Step b Synthesizer Frequency Hz 20 Limits of Computed Result 104 1 000 96 104 20 000 96 104 100 000 104 Low Level High input AC Level Accuracy 7 Remove the short from the Audio Analyzer s INPUT Connect the audio synthesizer s output directly to the Audio Analyzer Set the Audio Analyzer s INPUT switch to ground 8 Set the audio synthesizer to the frequency indicated in the table below For each setting perform the following procedure a Press RATIO if it is on Set the audio synthesizer to 7 mV rms as read on the Audio Analyzer Press RATIO b Decrease the level of the audio synthesizer by exactly 26 dB Note the reading of the right display of the Audio Analyzer c Multiply the reading on the right display by the entry in the table of step 2 which corresponds to the ac calibrator setting of 0 007 Vrms at the current frequency Divide the result by 5 01 Displayed Limits of Computed
265. tination Refer to Figure 2 2 for the part numbers of the power cables available 2 2 Model 8903B Installation HP IB Address Selection xr This task should be performed only by service trained persons who are aware of the potential shock hazard of working on an instrument with protective covers removed To avoid hazardous electrical shock the line Mains power cable should be disconnected before attempting to change the HP IB address In the Audio Analyzer the HP IB talk and listen addresses are selectable by an internal switch The following procedure explains how the switches are to be set Refer to Table 2 1 for a listing of the talk and listen addresses The address is factory set for a Talk address of V and a listen address of lt In binary this is 11100 in decimal it is 28 To change the HP IB address the top cover of the Audio Analyzer must be removed To avoid the possibility of hazardous electrical shock do not operate this instrument at line voltages greater than 126 5 Vac with line fre quencies greater than 66 Hz leakage currents at these line settings may exceed 3 5 mA Open cover door pull the FUSE PULL lever and rotate to left Remove the fuse Remove the Line Voltage Selection Card Position the card so the line voltage appears at top left cover Push the card firmly into the slot Rotate the Fuse Pull lever to its normal position Insert a fuse of the correct value in the holder Close t
266. tio mode can also be used to view an extra digit of resolution when the right display is only showing three digits Depending upon the current value displayed pressing either 100 RATIO or 1 RATIO will cause an unscaled right display readout that is the numbers are correct but the decimal point may not be in the correct position However an extra digit of resolution is displayed for example if 1 58 was originally displayed the new display might indicate 1 576 Note that the units annunciator will change to and should be interpreted properly Ratio cannot be used with a frequency measurement Also if a negative reference is entered the ratio indication will be displayed in absolute unsigned value The LOG function cannot be used with a reference that is zero or negative If the reference is zero Error 20 entered value out of range is displayed If the reference is negative Error 11 calculated value out of range is displayed RELATED SECTIONS AC Level DC Level Distortion Distortion Level Error Message Summary Signal to Noise SINAD Special Functions RATIO and LOG LIN 3 113 Model 8903B Read Display to HP IB Special Function 20 DESCRIPTION The Audio Analyzer can be set to read the information shown in either the left or right display to the HP IB Special Function 20 allows the operator to manually determine which display s information will be placed on the HP IB This capability is typica
267. tion Page Source ATpIIRUde S PLEX VEI IRE PEDES 3 44 Display Source Setting 3 57 Frogu NCY 3 74 I i6remelit 6408605552 ita a esas 3 83 Output Impedance 3 95 Measurements AC L8VOl d DEP ILE E IEEE 3 42 Common Mode 3 47 DG LOVE EUNDI ERAS EIU PE DNI 3 50 Detector Selection 3 53 iuto s roi 3 58 Distortion Level I e 3 60 Signal to Nosie 3 118 SINAD 3 120 Filters Filters Low Pass High Pass Bandpass NEA RES 3 68 UNG cire pP sede ber REN aer e ers 3 93 Post Notch Detector Filtering 3 100 Sweep and X Y Recording Plot DII d coco 3 98 Po edad es 3 130 Sweep Resolution 3 133 Time Between Measurements 3 136 Recording sire E RER UTE EIER En 3 137 Data Manipulation Display Level is Watts 3 55 Hold Decimal Point 3 76 RATIO and LOG LIN 3 111 Errors Error DISaDIG o nost eder 3 62 Error Message Summary 3 64 1 The detailed operating instructions are arranged in alphabetical order at the end of the Operation section
268. tion Ration Performance Test Input Flatness Adjustment Common Mode Rejection Adjustment Input DC Offset Adjustment 400 Hz High Pass and Weighting Bandpass Filters Adjustment Distortion and Noise Performance Test Distortion SINAD and Signal to Noise Accuracy Performance Test Notch Filter Tune and Balance Adjustment AC Level Accuracy and Output Level Accuracy and Flatness Performance Test Check ac level accuracy only DC Level Accuracy Performance Test Distortion and NOise Performance Test Distortion SINAD and Signal to Noise Accuracy Performance Test Voltmeter Adjustment SINAD Meter Adjustment Ac Level Accuracy and Output Level Accuracy and Flatness Performance Test Distortion and Noise Performance Test Frequency Accuracy and Sensitivity Performance Test Oscillator and Output Attenuator Adjustment AC Levei Accuracy and Output Level Accuracy and Flatness Performance Test Distortion and Noise Performance Test Input and Output Impedance Test Basic Functional Checks Frequency Accuracy and Sensitivity Performance Test Power Up Checks Basic Functional Checks Frequency Accuracy and Sensitivity Performance Test Internal Reference Frequency Adjustment Power Up Checks HP IB Functional Checks Power Up Checks A1 Keyboard and Display Assembly A2 Input Amplifier Assembly Notch Filter Assembly ADJ6 A4 Output Amplifier Voltmeter Assembly A5 Oscillator As
269. tions Input Level Range Except DC Level 3 89 Operation Model 8903B Monitor DESCRIPTION The rear panel MONITOR output provides a means of monitoring the ac signal into the output rms detector The auto ranging MONITOR output level is normally a 0 3 to 3 Vrms signal which is proportional to the input signal In ac level and dc level the MONITOR output provides a scaled representation of the ac component of the input signal In SINAD distortion and distortion level the MONITOR output provides a scaled representation of the input signal with the fundamental removed The output is dc coupled with a 600 output impedance and a BNC female connector The MONITOR output can be used to drive other test instruments such as an oscilloscope wave analyzer or spectrum analyzer for further analysis BLOCK DIAGRAM simplified block diagram of the Audio Analyzer measurement circuits illustrating the relationships between the MONITOR output and the other circuit blocks is shown below The MONITOR output block diagram illustrates the signal path from the INPUT to the MONITOR output The diagram is that of a programmable gain amplifier with a tunable notch filter In ac level dc level and signal to noise the notch filter is bypassed In SINAD distortion and distortion level the notch filter is switched into the signal path removing the fundamental frequency 477 INPUT STAGE GAIN eom POST NOTCH GAIN INTERNAL PLUG IN HP BP INPU
270. ues for the plot limits No adjustment of the x y recorder is necessary The Audio Analyzer also features high accuracy The instrument can typically measure flatness to 0 596 0 05 dB over the range of 20 Hz to 20 kHz and swept distortion over the same range to 0 003 90 dB See Figures 1 1 and 1 2 RESPONSE dB 2 20Hz SOHz 100Hz 200Hz S500Hz 1kHz 2kHz 5kHz 10kHz 20 kHz SOKHz 100 FREQUENCY Figure 1 1 Typical Combined Source and AC Level Flatness MmayzerOny DN RUNE AES Aa NN ASNT 20Hz 50Hz 200 Hz 500 Hz 2kHz 5kHz 20 kHz FREQUENCY J RESIDUAL DISTORTION and NOISE dB o t f p 3 5 3 v lt N i l E e Figure 1 2 Typical Combined Source and Analyzer Residual Distortion With Vsource Set to 1 5V 80 kHz BW Balanced input The Audio Analyzer has a selectable balanced input configuration for testing balanced devices For example in the quest for higher output power many audio amplifiers use bridged output stages Such amplifiers can be difficult to characterize because their outputs cannot be grounded To test these devices the usual approach has been to use a balanced calibrated isolation transformer connected to an analyzer with an unbalanced input Balanced inputs on the Audio Analyzer make transformers unnecessary With the analyzer input in the float position connect the bridged devi
271. um accuracy is desired it is recommended that this data be reacquired approximately each hour or each time a different Audio Analyzer is used Entering and Terminating Rapid Source Mode Rapid Source mode is entered immediately when the Audio Analyzer receives the HP IB code RS Rapid Source mode is terminated whenever any Audio Analyzer front panel key is pressed or whenever the Attention bus control line is set true that is whenever any bus command or talk or listen address is placed onto the bus NOTE Once the Rapid Source code has been issued to the Audio Analyzer no bus activity should occur until the tuning is completed Bus activity may cause the Rapid Source mode to be prematurely terminated EXAMPLE To obtain the tuning data to tune the Audio Analyzer to 1000 Hz first tune the Audio Analyzer by conventional techniques Function Datas Unit LOCAL keystrokes 1 Ed Unit IA LL program codes Function Now use the Special Functions to obtain the tuning data First get the range data Code s Function LOCAL SPCL keystrokes Ls 5 C a gt 55 SP L Function program codes For example the right display on the Audio Analyzer shows a 1 decimal which equals 0001 in binary 3 108 Rapid Source Model 8903B Operation Now obtain the coarse tune data rm Code Function LOCAL keystrokes Cs O B 5 x
272. umeric data and unit keys Once the FREQ key has been pressed new data and unit entries can be made to select different frequencies until another source function key for example the AMPTD key is pressed To display the currently programmed source frequency press and hold the FREQ key EXAMPLE To set the source frequency to 500 Hz Function s Data A Unit LOCAL aere AOR x FR500HZ AE sis program codes Data PROGRAM CODES a J FREQ FR Hz HZ kHz KZ INDICATIONS When the FREQ key is pressed the left display shows the currently set frequency setting the new frequency data is entered it will appear on the left display When the unit key is pressed the left display returns to show the input signal frequency 3 74 Frequency _ _ Model 8903B Operation COMMENTS When the FREQ key is pressed and held the left display shows the currently programmed frequency It is important to realize the value shown in the left display is the programmed value which can differ from the actual frequency at the output This difference is caused by the fact that the source is a programmable oscillator and not a synthesizer However the source frequency is within 0 3 of the entered value Also realize that the displayed count is the frequency of the input signal and is the sam
273. unction code 2 0 was entered the light within the SPCL key will turn on if not already on If the light is already on it will remain on 3 86 Input Level Range DC Level Model 8903B Operation COMMENTS When the Audio Analyzer powers up or when AUTOMATIC OPERATION is selected the input level range is placed in the automatic selection mode If the input level range is set such that the input signal level causes the input overload detector to trip Error 30 will be displayed Manually selecting the gain of the input level circuitry can cause measurement error Measurement accuracy is not specified whenever the gain of the input level circuitry is manually selected because the selected gain setting may be less than optimum It is important to note that error messages indicating invalid measurements due to incorrect gain settings are not generated unless overload conditions occur Automatic operation ensures accurate measurements for all combinations of input signals and measurement modes RELATED SECTIONS Automatic Operation DC Level Input Level Range Except DC Level Monitor Special Functions Input Level Range DC Level 3 87 __ _ Operation Model 8903B Input Level Range Except DC Level Special Function 1 DESCRIPTION In all measurement modes the input level range can be manually set by key
274. ure and select a measurement X Y RECORDER PEN LIFT OUTPUT AUDIO ANALYZER DEVICE UNDER TEST X Y Recording Setup 2 The START FREQ and STOP FREQ keys are used to establish the two reference points needed for adjusting the X Y recorder X and Y axes These two references determine the plotting area or plot dimension The START FREQ key sets both the X AXIS and Y AXIS outputs to 0 volts This reference point corresponds to the lower left corner of the graph To set the lower left corner point press the START FREQ key and adjust the zero controls on the X Y recorder to position the pen to the lower left corner of the graph The STOP FREQ key sets both the X AXIS and Y AXIS outputs to 10 volts This reference point corresponds to the upper right corner of the graph To set the upper right corner point press the STOP FREQ key and adjust the vernier controls on the X Y recorder to position the pen to the upper right corner of the graph X Y Recording 3 137 LL Operation Model 8903B 3 The Y axis scaling unit is determined by the displayed measurement unit in th e right display Any displayed measurement unit except mV can be used when plotting To scale the Y axis key in the desired upper and lower plot limit 4 The X axis corresponds to the frequency span of the Audio Analyzer source The frequency scaling of the X axis is in logarithmic units To scale the X axis key in the desired start and stop frequencies
275. ureau of Standards to the extent allowed by the Bureau s calibration facility and to the calibration facilities of other International Standards Organization members WARRANTY This Hewlett Packard instrument product is warranted against defects in material and workmanship for a period of one year from date of shipment During the warranty period Hewlett Packard Company will at its option either repair or replace products which prove to be defective For warranty service or repair this product must be returned to a service facility designated by HP Buyer shall prepay shipping charges to HP and HP shall pay shipping charges to return the product to the Buyer However Buyer shall pay all shipping charges duties and taxes for products returned to HP from another country HP warrants that its software and firmware designated by HP for use with an instrument will execute its programming instructions when properly installed on that instrument HP does not warrant that the operation of the instrument or software or firmware will be uninterrupted or error free LIMITATION OF WARRANTY The foregoing warranty shall not apply to defects resulting from improper or inadequate maintenance by Buyer Buyer supplied software or interfacing unauthorized modification or misuse operation outside of the environmental specifications for the product or improper site preparation or maintenance NO OTHER WARRANTY IS EXPRESSED OR IMPLIED HP SPECIFICALLY DI
276. used Monitor 3 91 Ss ee et oo Model 8903B In SINAD distortion and distortion level the fundamental frequency is removed suppressed by more than 80 dB The output after the notch filter includes all harmonics of the fundamental plus any noise hum and other spurious signals that may be present These signal impurities are amplified and are available at the MONITOR for further analysis The following equations express the MONITOR output level as a function of the parameter being measured the displayed reading Use linear Net Gain For distortion V _ Displayed Reading in 96 x Vin x Net Gain oui 0 10 Or Vou 10P splayed Reading in dB 20 X Net Gain For distortion level Vou Displayed Reading in volts x Net Gain Or are 102 splayed Reading in dBm 20 S Net Gain For SINAD I 100 Vout Reading m 09 Vi X Net Gain Vout Displayed Reading in Vout 10 7 Displayed Reading in dB 20 X Net Gain In the above equations is the MONITOR output level as measured with a true rms voltmeter and Vi is the input signal level In the SIG NOISE measurement mode the source is turned on and off Therefore the signal level at the MONITOR output is constantly alternating The MONITOR output does not respond to dc signals presented at the INPUT In the dc level measurement mode only the ac components of the input signal are prese
277. ut detector The output detector converts the ac level to a dc voltage which is then measured by the dc voltmeter After correcting input gain and attenuation the signal level is displayed in appropriate units The frequency of the input signal level is also measured and displayed 3 42 AC Level Model 8903B m Operation COUNTER LEFT DISPLAY FREGUENCY INTERNAL DO T FILTERS AV VOLTMETER LON PASS DETECTOR RIGHT DISPLAY INPUT ATTENUATOR AMPLITUDE H INPUT PROGRAMABLE PROGRAMABLE AMPLIFIER GAIN AMPLIFIER GAIN AMPLIFIER CS MONITOR AC Level Measurement Block Diagram COMMENTS The Audio Analyzer powers up in the ac level measurement mode with the 80 kHz low pass filter activated The 80 kHz low pass filter reduces the measurement bandwidth from 750 kHz to 80 kHz CAUTION THE INPUT SIGNAL IS NOT TO EXCEED 300V EITHER WITH RESPECT TO GROUND OR DIFFERENTIAL Some input signal limitations apply to the level of common mode signals See the Common Mode detailed operating instruction for details NOTE See the Detector Selection section for more detailed information concerning rms and average detecting RELATED SECTIONS Common Mode Detector Selection Display Level in Watts Filters Monitor RATIO and LOG LIN Special Functions AC Level 3 43 Model 8903B Amplitude DESCRIPTION The Audio Analyzer contains a low distortion audio source The AMPTD key
278. ut of the filter relative to the input This is the method used by the Audio Analyzer in the DISTN mode where the tuning and measuring are done automatically When using the distortion analyzer method it is important to understand that the measurement result is not total harmonic distortion as defined above except under the condition that the distortion is not too excessive but that it does predominate over any other signal impurities Some examples will illustrate these restrictions 2 The Institute of High Fidelity Inc Standard Methods Of Measurement For Audio Amplifiers The Institute of High Fidelity Inc New York 1978 p 9 1 14 Model 8903B General Information Consider the case of excessive harmonic distortion Let us use the example of a signal with 1096 actual total harmonic distortion in which all the distortion comes from the second harmonic The second harmonic is then 20 dB below the fundamental as viewed on a spectrum analyzer When this signal is measured by a distortion analyzer an error results from tbe first part of the measurement measuring the input level because the input level is not quite the same as the level of the fundamental If the fundamental level were 1 Vrms the second harmonic level would be 0 1 Vrms one tenth of the fundamental The total input level measured with a true rms voltmeter is the rms sum of the two components namely Input 4 1 0 1 1 005V or 0 5 high Thus the measur
279. vel greater than 2 4V then drop to a TTL low level less than 0 4V and remain there until the sweep is complete The display should then show a TTL high level 3 15 m Model 8903B 3 6 HP IB FUNCTIONAL CHECKS 3 16 Description The following ten procedures check the Audio Analyzer s ability to process or send all of the applicable HP IB messages described in Table 3 3 In addition the Audio Analyzer s ability to recognize its HP IB address is checked and all of the bus data handshake and control lines except DIO8 the most significant data line which is not used by the Audio Analyzer are set to both their true and false states These procedures do not check whether or not all Audio Analyzer program codes are being properly interpreted and executed by the instrument however if the front panel operation is good the program codes in all likelihood will be correctly implemented The validity of these checks is based on the following assumptions e The Audio Analyzer performs properly when operated via the front panel keys that is in local mode This can be verified with the Basic Functional Checks e The bus controller properly executes HP IB operations e The bus controller s HP IB interface properly executes the HP IB operations If the Audio Analyzer appears to fail any of these HP IB checks the validity of the above assumptions should be confirmed before attempting to service the instrument The se
280. xponent or Byte 7 E exponent Bytes 2 6 DDDDD reading from display where Byte 6 corresponds to the least significant digit of the reading in the display Byte 1 Sign or Data is always output in fundamental units that is Hz dB or V Error messages and the voltage value in dc level mode are always read out regardless of the status of the Read Display to HP IB commands RELATED SECTION Special Functions Read Display to HP IB 3 115 Operation Model 8903B Service Request Condition Special Function 22 DESCRIPTION The Audio Analyzer will issue a Require Service message under various circumstances For example a Require Service message will always be issued if an HP IB code error occurs Using the keyboard and the SPCL key the operator may enable one or more conditions to cause the Require Service message to be issued Whenever the enabled condition occurs it sets both the bit corresponding to the condition and bit 7 RQS bit in the Status Byte The bits set in the status byte and the Require Service message are not cleared unless the status byte is read by serial polling a Clear message is received and executed by the Audio Analyzer or a Controller Reset or Controller Clear Service Special Function is performed The enabled Service Request conditions are always disabled again whenever a Clear message is received and executed by the Audio Analyzer or whenever a Controller Reset or Controller Clear Servi
281. yzer input and output circuitry isolates the LOW center conductor of the Audio Analyzer from chassis ground Thus the Audio Analyzer input and output circuits are grounded only through the device under test Note that the system common line is now grounded at a single point A simplified diagram of the source output circuit is shown below Note that in the float mode there is no ground present at the output actually the center conductor of the LOW terminal is connected to chassis ground through a 1 resistor 8903B SOURCE 50 600 qv Simplified Schematic of the Audio Analyzer Source Output In the float mode the output can be used as a summing circuit An external source either ac or dc can be applied to either the HIGH or LOW connectors The output signal is the sum of the internal source plus the external source The OUTPUT LOW and HIGH connectors can be floated up to 10V peak CAUTION Do not allow the voltage at the OUTPUT LOW or OUTPUT HIGH connector to be greater than 10V or less than 10V ac Float 3 73 Model 8908 Frequency DESCRIPTION The Audio Analyzer provides a low distortion sine wave output from 20 Hz to 100 kHz The FREQ key along with numeric data and unit keys are used to program the frequency of the source The FREQ key is also used to display the currently programmed frequency PROCEDURE To set the source frequency press the FREQ key and then the appropriate n
282. zer listed in the following table For each setting the Audio Analyzer s left display should read within the limits indicated Frequency Limits Hz j SOURCE Frequency Hz 200 6 2 006 20 060 100 300 4 20 Performance Test 5 Model 8903B Performance Tests Performance Test 6 AUDIO FILTERS PERFORMANCE TEST Specification IS 0 emo Limits MEASUREMENT AUDIO FILTERS 30 kHz Low Pass Filter 3 dB Cutoff Frequency 80 kHz Low Pass Filter 3 dB Cutoff Frequency 400 Hz High pass Filter Option 010 or 050 3 dB Cutoff Frequency CCITT Weighting Filter Option 011 or 051 Deviation from Ideal Response CCIR Weighting Filter Option 012 or 052 Deviation from Ideal Response 30 kHz 2 kHz 80 kHz 4 kHz 400 Hz 40 Hz 2 0 dB 1 4 dB 1 0 dB 0 85 dB 0 7 dB 0 55 dB 0 5 dB 0 2 dB 0 4 dB 0 6 dB 0 8 dB 1 2 dB 1 65 dB 2 0 dB 2 8 infdB at 800 Hz 300 Hz to 3 kHz 50 Hz to 300 Hz 3 kHz to 3 5 kHz 3 5 kHz to 5 kHz 31 5 Hz to 63 Hz 63 Hz to 100 Hz 100 Hz to 200 Hz 200 Hz to 400 Hz 400 Hz to 800 Hz 800 Hz to 1 kHz 1 kHz to 6 3 kHz 6 3 kHz to 8 kHz 8 kHz to 9 kHz 9 kHz to 10 kHz 10 kHz to 12 5 kHz 12 5 kHz to 14 kHz 16 kHz to 20 kHz 20 kHz to 31 5 kHz at 31 5 kHz See the International Telegraph and Telephone Consultative Committee CCITT Fifth Plenary Assembly 1972 Telephone Transmission Quality The International Telecommunication U

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