HP 8901B Operation And Calibration Manual page 361

Model 8901B Performance Tests
Lower Actual
2.88
-
2.88
-
2.88
-
2.88
-
Description
Upper
3.12
3.12
3.12
3.12
All audio measurements are made on external audio signals. Level accuracy is measured by comparing
the voltage reading on the Modulation Analyzer with the output from a more accurately set audio
oscillator. Residual distortion and noise is measured by making a distortion measurement on a low-
distortion oscillator. Measurements must be made at several frequencies within the notch filter range to
verify proper nulling of the fundamental. Distortion accuracy is measured by summing a low-distortion
output from one oscillator with the output of an oscillator which is set to generate a second through
fifth harmonic of known magnitude. The audio counter is checked by counting the signal from a audio
frequency synthesizer set
to
both high and low levels.
Lower Actual
96
96
96
96
Equipment
Upper
1 04
1 04
1 04
1 04
Audio Analyzer
...................................................................
HP 8903B
Audio Synthesizer.
................................................................
HP 3336C
Procedure
Audio
RMS
Accuracy
1.
On the Modulation Analyzer, press the blue key then press INSTR PRESET (the AUTOMATIC
OPERATION key)
to
preset the instrument. Key in 30.0
SPCL
to
set the Modulation Analyzer
to measure external audio
rms
level.
2. Set the audio synthesizer
to 50 Hz at +16.54 a m . (To produce 3V, the synthesizer is set to
deliver 1.5V or +16.54 dBm into 500; this becomes 3V when applied to the 100 kS1 audio input
of the Modulation Analyzer.)
3. Connect the audio synthesizer output
to
the Modulation Analyzer's MODULATION OUT-
PUT/AUDIO INPUT connector.
4.
Set the audio synthesizer to the frequencies shown in the following table. For each setting, the
Modulation Analyzer's display should read between the limits indicated in the table.
c
Audio
Synthesizer
Frequency (Hz)
50
500
5 000
40
000
5. Set the audio synthesizer level
to -13.01 dBm (100 mV at the audio input). Set the audio
synthesizer to the frequencies shown in the following table. For each setting, the Modulation
Analyzer's display should read between the limits indicated in the table.
Audio
Synthesizer
Frequency (Hz)
40
000
5 000
500
50
Performance Test 5
4-21