SJ 20255-1993 Verification procedures for HP3779C base group multiplexing analyzer
Some standard content:
Military Standard of the Electronic Industry of the People's Republic of China FL0150
SJ20255—93
Verification regulation of naodelHP 3779 C primary multiplexer
analyzer (CEPT)
Published on February 9, 1993
China Electronics Industry Corporation
Implemented on May 1, 1993
Military Standard of the Electronic Industry of the People's Republic of China HP3779C Primary Multiplexer
Verification regulation of modelHP 3779 C primary multiplex
analyzer(CEPT)
1 Scope
1.1 Subject content
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This verification procedure specifies the verification conditions, verification items, verification methods, verification result processing and verification cycle of HP3779C base group multiplex analyzer. 1.2 Applicable scope
This verification procedure is applicable to the verification of HP3779C base group multiplex analyzer only, and other types of base group multiplex analyzers and voice channel characteristic measuring instruments can also be used for reference. 2 Referenced documents
There are no provisions in this chapter.
3 Definitions
There are no provisions in this chapter.
General requirements
China Electronics Industry Corporation 1993-02-09 Issued 1993-05-01 Implementation
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4.1 Purpose and principle of the inspected measuring instrument
HP3779C base group multiplexing analyzer can be used to test the main voice path characteristics of the PCM and FDM system terminals, as well as the characteristics of the PCM encoder and decoder. The instrument is mainly composed of analog generators, analog receivers, digital generators, digital receivers, etc.
4.2 Technical requirements
4.2.1 Analog generator part (output terminal Tx, output impedance 6000 balanced) 4.2.1.1 Sine wave signal output
4.2.1.1.1 Frequency range: 40Hz～40kHzl4.2.1.1.2 Frequency error: ±50ppmg
4.2.1.1.3 Level range: +13~ -76.9dBm 4.2.1.1.4 Level error (at 1kHz): =0.5dB4.2.1.1.5 Frequency response (based on 1kHz): 40Hz～10kHz±0.05dB 4.2.1.2 Dual sine signal outputbzxz.net
4. 2.1.2.1 Frequency range: 40Hz～4kHz#4.2.1.2.2 Frequency error: 50ppm1
4.2.1.2.3 Level range: +10~-76.9dBm#4.2.1.2.4 Level error (at 1kHz): ±0.5dB. 4.2.1.3 Noise signal output
4.2.1.3.1 Attenuation/frequency response: in accordance with CCITT recommendation 0·131: 3dB bandwidth ≥100HIz;
4.2.1.3.2 Crest factor: 10.5dB±0.5dB. 4.2.1.4 T, return loss: 40Hz~～40kHz, ≥30dB. 4.2.1.5T, signal balance ratio: 40Hz~40kHz, ≥40B4.2.2 Analog receiver part (input terminal R, input impedance 6002 balanced) 4.2.2.1R, wave loss: 40~~300Hz, ≥30dB2
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300Hz~4kHz, ≥46dB
4.2.2.2R, signal balance ratio: 40~3400Hz, ≥75dB; 40Hz~4kHz.2G 0dB;
4~40kHz,246dB.
4.2.3 Digital generator part
4.2.3.1 Internal clock output
4.2.3.1.1 Output frequency: 2048kbits±50ppm;4.2.3.1.2 Voltage amplitude: high level, 3V10%: low level, ≤0.3V;
4.2.3.1.3 Pulse width; 244ns±12%4.2.3.1.4 Overshoot; ≤10%.
4.2.3.2 PCM data signal input period
4.2.3.2.1 Voltage amplitude: high level, 2.37V, 10%: low level, ≤0.24V:
4.2.3.2.2 Overshoot ≤10%;
4.2.3.2.3 Rise and fall time: ≤30ns4. 2. 3. 2. 4 Pulse width: 244ns±12%, 4.2.4 A-A measurement accuracy
4. 2. 4. 1 A-A gain accuracy
200Hz～4kHz.T, and R, when the level is ≥-25dBm.±0.04dB. 4. 2. 4. 2A-A Intermodulation accuracy
R, level (signal A)
R level (combination)
Signal A/1
≥36dBmz
≥-76dBm
≤30dB,=0.2dB
≤40dB.=0. 3dB:
≤50dB,=0. 1dB.
4. 2. 4. 3A - A Gain frequency characteristics Reference frequency 200Hz~3.4kHz can be selected arbitrarily, output level ≥-25dBm3
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Receiving bandwidth is 40Hz:
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40~-200Hz,
Main 0. 16a3:
200Hz~3.4kHz±0.07dB;
3.4～4kHz,±0.I0dB;
Receiving bandwidth 3kHz:
±0.6B.
200~3400Hz,±0.09dB:
3400~4000Hz,±0.12dB.
4.2.4.4AA gain level characteristic (noise) accuracy (reference level -10dBm):
R level
≥-52
T, electric power
±heart,18
pain degree
4.2.4.5AA air-road noise (noise meter) accuracy R, level ≥-80dBm: ±0.5dB; R, level ≥90tBm: -1.1dB.
4.2.4.6AA quantization distortion (noise) accuracy R. Distortion level
(dEnt)
4.3 Verification conditions
4.3.1 Environmental conditions
Quasi-phosphorus (dB)
±26
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20±2℃
a. Ambient temperature: 2
b. Relative humidity: 45%~75%
e. Atmospheric pressure: 86~106kPa:
d. Power supply: 220V±2%, 50Hz±1%; e. Surrounding environment: no mechanical vibration and electromagnetic field interference that may affect normal operation. 4.3.2 Calibration equipment
4.3.2.1 Spectrum analyzer
Frequency range: 40Hz～40kHz
Level accuracy: ±0.5dB;
Reference model: 3580A spectrum analyzer. 4.3.2.2 Digital multimeter
Measurement accuracy: 40Hz～20kHz
20~~40kHz
±0.15%;
Reference model: PM2519 digital multimeter. 4.3.2.3 Dual-trace oscilloscope
Bandwidth: DC～100MHz;
Voltage accuracy: 2%,
Time base accuracy: ±1.5%;
Reference model: 2235 oscilloscope.
4.3.2.4 Frequency counter
Rated frequency range: 40Hz～40kH2;
Frequency accuracy: ±1×10-;
Reference model: E312 general purpose counter. 4.3.2.5 Level oscillator
Frequency range: 40Hz～40kHz;
Output level error: ≤±0.IdB:
Reference model: PSE-11 level oscillator, 4.3.2.6 Frequency selective level meter
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Frequency range:
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40Hz～40kHz:
Selection bandwidth: 8Hz:
Level error: ≤±0.1dB;
Frequency error: ≤±1X10-5;
Reference model: SPM-11 frequency selective level meter. 4.3.2.7 Variable attenuator
Frequency range: 40Hz~40kHz
Attenuation range: 0～40dB;
Attenuation accuracy: ≤0.008dB
Impedance, 6000 balance;
Reference model: D110 variable attenuator (for use with correction value). 4.3.2.8 Signal balance ratio measurement bridge
Signal balance ratio measurement bridge that complies with CCITT Recommendation 0·121. 4.3.2.9 Standard zero-level meter
Frequency range: 40Hz~40kHz;
Zero-level error: ±0.015;
Reference model: EPM-1 standard zero-level meter. 4.3.2.10 Return loss measurement bridge
Frequency range: 40Hz~40kHz
Impedance: 6000;
Reference model: RF1-12 impedance reflection bridge. 4.3.2.11 Power divider
Frequency range: 40Hz～40kHz
Impedance: 6000
Attenuation at any two ends: 6.02dB±0.05dB;Reference model: Homemade.
5 Detailed requirements
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5.1 Verification items and verification methods
5.1.1 Appearance and normal working inspection
5.1.1.1 The base group multiplexing analyzer under inspection (hereinafter referred to as the inspected instrument) shall be accompanied by the product technical manual and necessary accessories. If it is not the first verification, the previous verification certificate shall be attached.
5.1.1.2 The instrument under test should have no mechanical damage that affects its normal operation, and the switches and buttons should be reliable.
5.1.1.3 After the instrument under test is powered on, operate according to the steps in the manual, perform self-calibration and interrogation measurement mechanism inspection, and it should work normally.
5.1.1.4 Use a digital voltmeter and frequency meter to test the output voltage and frequency of the analog receiver standard source. The output voltage of the standard source should be within 3.535Vrms and 0.2%; the frequency should be 1kHz±50ppm.
5.1.2 Verification of the analog part
5.1.2.1 Verification of the sine wave frequency
5.1.2.1..1 Connect the instrument according to Figure 1.
Tested Instrument
Frequency
5.1.2.1.2 Set the tested instrument to the outer loop mode, and set the impedance to 6000. 5.1.2. 1. 3 Set the test frequency points of the tested instrument according to Table A1 in Appendix A (Supplement), read the measured frequency value displayed by the frequency meter, calculate the frequency error 8 according to formula (1), and record the result in Table A1.
8=fx×100%
Where: The nominal value of the auxiliary output frequency of the tested instrument: f, — the measured value of the output frequency of the tested instrument. 5.1.2.2 Verification of Sine Wave Level
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5.1.2.2.1 Connect the tester according to Figure 2.
Tested instrument
Selected frequency meter
5.1.2.2.2 Set the output impedance of the tested instrument to 6000, the frequency to 1kHz, the output level to 0dBm, and read the measured value of the level on the frequency-selective level meter. 5.1.2.2.3 Set the nominal value of the output level of the tested instrument according to Table A2, read the measured value of the level from the frequency-selective level meter, calculate the level error AP according to formula (2), and record the result in Table A2.
Where: Px—nominal value of the output level of the tested instrument, dBm: P..-----measured value of the output level of the tested instrument, dBm. 5.1.2.3 Verification of sine wave response
5.1.2.3.1 Connect the instrument according to Figure 3.
Tested instrument
Standard level meter
5.1, 2. 3. 2 Set the output impedance of the tested instrument to 60002, the frequency to 1kHz, take 0 dBm as the reference, change the frequency according to Table A3, and read the zero-level measured value of each frequency point on the standard level meter. Calculate the new response error 4P according to formula (3) and record the result in Table A3.
APr=P,-Pe
Where: P,——zero-level measured value of each frequency point, dB; Pro——1kHz zero-level measured value, dB. 5.1.2.4 Verification of the frequency of double sine wave signal 8
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5.1.2.4.1 Connect the instrument according to Figure 2.
5.1.2.4.2 The output impedance of the instrument under test is set to 6000, the output level is 0dBm, and the frequencies of signals A and B are changed according to Table A4. However, the frequency interval between signals A and B must be greater than 50Hz.
5.1.2.4.3 The impedance of the frequency-selective level meter is set to 6002. The frequency-selective bandwidth is set to 8Hz. Tune to the maximum level indication at each corresponding test frequency point, then read the frequency display value, calculate the frequency error using formula (1), and record it in Table A4. 5.1.2.5 Verification of the output level of double sine wave signals 5.1.2.5.1 Connect the instrument according to Figure 2.
5.1.2.5.2 The output impedance of the instrument under test is set to 6002, signal A is set to 1kHz, the frequency interval between signal B and signal A is >50Hz, and the output level is set to 0dBm; the impedance of the frequency-selective level meter is set to 600α, and the bandwidth is set to 8Hz. Tune the frequency-selective level meter to maximize the level indication, read the measured value of the signal A level, and record it in Table A5.
5.1.2.5.3 Change the level of the instrument under test as specified in Table A5, read the corresponding measured value of the level from the frequency-selective level meter, calculate the level error AP according to formula (2), and record the result in Table A5.
5.1.2.5.4 Verify the output level error of signal B according to the methods in 5.1.2.5.2 to 5.1.2.5.3, and record the result in Table A5. 5.1.2.6 Verification of noise signal attenuation/frequency characteristics 5.1.2.6.1 Connect the instrument as shown in Figure 4.
Tested instrument
Spectrum analyzer
5.1.2.6.2 Set the output impedance of the tested instrument to 600Ω, the output level to 0dBm, and adjust the spectrum analyzer. The displayed graph is shown in Figure 5, which should comply with CCITT 0·131 recommendations.
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350H580Hs
5.1.2.6.3 Read the 3dB bandwidth and record it in Table A6. 5.1.2.7 Verification of the peak factor of the noise signal 5.1.2.7.1 Connect the instrument according to Figure 6.
Tested instrument
8001000
Music instrument
Digital multimeter
5.1.2.7.2 Set the output impedance of the tested instrument to 6000, connect it to the oscilloscope, and read the peak-to-peak value of the media signal voltage.
5.1.2.7.3 Disconnect the oscilloscope, connect the digital multimeter, and read the effective value of the noise signal voltage (10 times average).
Calculate the peak factor CFo and the peak factor error ACFn according to formulas (4) and (5) respectively, and record the results in Table A?.
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CFo=20lg
-peak-to-peak value of noise signal voltage, V;
Vm effective value of media signal voltage, V
△CF,=CFx-CF. .....
Where: CFx is the nominal value of the return factor of the instrument under test; CF is the measured value of the return factor of the instrument under test.
5.1.2.8 Verification of analog output and input return loss 5.1.2.8.1 Connect the instrument according to Figure 7.
Standard resistor
Level oscillator
Commercial wave attenuation
Measurement bridge
Inspect instrument
5.1.2.8.2 Set the impedance of all instruments to 6000. (5)
Frequency-selective level meter
5.1.2.8.3 Adjust it to balance according to the method of using the echo consumption measurement bridge.The level oscillator and the frequency-selective level meter are synchronized according to the test frequency points in Table A8. 5.1.2.8.4 At each frequency point, read the level reading P of the frequency-selective level meter when the instrument under test is not connected, then connect the instrument under test and read the level reading Px of the frequency-selective level meter.
Calculate the return loss A, according to formula (6), and record the result in Table A8. A,-P.Px ++r+++++*++++++++++++++++ (6)TKAONKAca-
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