HP 8901B Operation And Calibration Manual page 171

Model 8901B
Operation
HP
89016
MODULATION
ANALYZER
MODULATION
AUDIO
INPUT
0
0 0
0 0 0 0 0 0
0
0000
0
I
I
I
SIGNAL GENERATOR
OSCILLOSCOPE
IO
INPUT
I
(STEP
32)
(STEP
3 3 )
Figure 3-10. External Audio
RMS
Level Check Setup
Audio Detector Check
34. Disconnect the signal generator's audio output. Press the FM key. Set the signal generator's AM
off and set the FM on with a peak deviation of 50 kHz and a rate of 1 kHz. Press the RATIO
key then the LOG/LIN key to
%
to establish a reference of 100%. Set DETECTOR to PEAK-.
The Modulation Analyzer should display between 95 and 105% REL depending upon the signal
generator's
FM
distortion.
35. Set DETECTOR to PEAKi/2 by pressing both the PEAK+ and PEAK- keys simultaneously.
The Modulation Analyzer should display a value between
100%
and the value read in
step
34.
36. Press the AVG key. The instrument should display between 69.3 and 72.1% REL. Turn the ratio
function off by pressing the RATIO key again.
37. Press the PEAK+ key then press the PEAK
HOLD
key. Switch the signal generator's FM off.
The Modulation Analyzer's display should retain the largest value obtained after pressing PEAK
HOLD.
Turn
off the peak hold function by pressing the PEAK+ key.
IF Level Check
38. Press the S (Shift) key then the IF LEVEL key (the OM key). The Modulation Analyzer should
display between 99.9 and 100.1%.
IF Frequency
and
LO Frequency
39. Set the signal generator to 100.000 MHz CW at 0 dBm. (Accurately set its frequency.) Press the
AUTOMATIC OPERATION key then key in 34.0 and press the SPCL key to display the IF
frequency. The frequency displayed should be between 1.45 and 1.55 MHz.
40. Key in 33.0 and press the SPCL key to display the LO frequency. The frequency displayed should
be between 101.45 and 101.55 MHz.
41. Key in 3.1 and press the SPCL key. (Special Function 3.1 switches the IF bandwidth back to 455
kHz.)
The
frequency displayed should be between 100.44 and 100.46 MHz.
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