HP 8901B Operation And Calibration Manual page 352

Performance Tests Model
8901B
Audio
Synthesizer
Frequency (HZ)
50 000
100 000
50
20
16. Set the audio synthesizer to 10 kHz at +5 dBm. Connect its output to the audio input of the
AM/FM test source. (See Figure 4-2.) Fine adjust the level for a Modulation Analyzer display of
100
kHz
times the calibration factor of step 5. (For example, if the calibration factor of step 5 is
100.4%, set the level
for
a display
of
100.4
kHz.)
FM Limits (kHz)
Lower Actual Upper
98.9
-
101.1
94.9
-
105.1
98.9
-
101.1
94.9
-
105.1
NOTE
Flatness
of
the audio synthesizer i s critical for this test. If the audio
synthesizer
has
leveling capabilio, switch it on.
17. Set the audio synthesizer
to the frequencies in the following table. For each setting, the Modulation
Analyzer's display should read between the limits indicated in the table.
I
I I
I
I
18. On the Modulation Analyzer, set HP FILTER
to
50
Hz
and LP FILTER
to
3 kHz.
19. Set the audio synthesizer frequency to 1 kHz. Set the level for a Modulation Analyzer display of
20. On the Modulation Analyzer, press AM. Momentarily disconnect the audio input
to the AM/FM
50 kHz peak deviation.
test source and note the residual AM displayed on the Modulation Analyzer.
Residual
AM:
%
21. Reconnect the audio input of the AM/FM test source. Note the AM displayed on the Modulation
Analyzer. The displayed
AM
minus one-half the residual
AM
noted in step 20 should be 0.2%
or less.
FM Rejection at 1 kHz Rate; 50 kHz Peak Deviation:
0.2%
FM
Distortion, Accuracy, and Rejection-455
kHz IF
22. Connect the FMt32 output of the AM/FM
test source to the Modulation Analyzer's INPUT.
23. On the Modulation Analyzer, key in 3.1 SPCL to set the IF to 455 kHz. Press FM.
24. Set the audio synthesizer level for a Modulation Analyzer display of 5 kHz peak deviation.
25. On the Modulation Analyzer, press AM. Momentarily disconnect the audio input to the AM/FM
(See Figure 4-2.)
test source and note the residual AM displayed on the Modulation Analyzer.
Residual AM
%
26. Reconnect the audio input of the AM/FM test source. Note the AM displayed on the Modulation
Analyzer. The displayed AM minus one-half the residual AM noted in step 25 should be 0.2%
or less.
FM Rejection at
1
kHz Rate; 5 kHz Peak Deviation:
0.2%
4-12
Performance Test 2