Adjustment 7 - HP 8901B Operation And Calibration Manual

Adjustments
Model 8901B
Adjustment 7
15 KHZ AND >20 KHZ LOW-PASS FILTER GAIN
Service Sheet 12
Description
A
signal generator is amplitude modulated at a 1 kHz rate. The signal is demodulated by the Modulation
Analyzer with no low-pass, audio filtering. Using the ratio feature, the demodulated signal is referenced
to 100%. The low-pass filtering is then set to
>20
kHz and 15
kHz,
then the filter gain of each is
adjusted for a reading of 100%.
Equipment
Signal Generator.
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H P 8640B
Procedure
1 , Set the signal generator
to
11 MHz at 0 dBm with
30% AM at
a
1 kHz rate. Connect its
F W
output to the Modulation Analyzer's INPUT. (The signal source can be connected either to a
sensor module or directly to the Modulation Analyzer's INPUT.)
2. On the Modulation Analyzer, press the blue key then press INSTR PRESET (the AUTOMATIC
OPERATION key) to preset the instrument. Press AM.
Set DETECTOR
to
AVG.
3. Set
RATIO on (with LOG/LIN set for a linear display). The display should show between 99.95
and 100.05% REL.
4. Set LP FILTER
to
>20 kHz. Adjust A2R44
(
>20 kHz LPF GAIN) for a display of 99.95 to
100.05% REL.
5.
Set LP FILTER to 15 kHz. Adjust A2R40 (15
kHz
LPP GAIN) for a display of 99.95 to
100.05% REL.
5-14
Adjustment 7