HP 8901B Operation And Calibration Manual page 350

Performance Tests Model 8901B
NOTE
I n the following procedure the RF modulation source can be connected
either to a sensor module (which
is
connected to the Modulation Analyzer)
or directly to the Modulation Analyzer's INPUT connector. The procedure
is
written for the latter case.
Procedure
Residual
FM
1. On the AMFM
test source, set the test mode to residual FM. Connect its low-residual(560 MHz)
2.
On the Modulation Analyzer, press the blue key then press INSTR PRESET (the AUTOMATIC
output to the Modulation Analyzer's INPUT. (See Figure
4-2.)
OPERATION key)
to
preset the instrument. Set the other controls as follows:
Measurement
.................................................................
FM
H P
Filter..
................................................................
. 5 0 Hz
L P Filter
..................................................................
. 3 kHz
Detector.
....................................................................
AVG
The display should read
4
Hz or less.
Residual FM at 560 MHz; 50 Hz to 3
kHz
bandwidth
4
Hz
NOTE
The equation for determining the residual FM limits
i s :
residual FM
in
Hz
=
5.83 x carrier frequency
in
GHz
+
0.42
Hz.
For a carrier of
560
MHz, the residuul FM limit
is
3.7 Hz. Allowing for one
digit of uncertainty gives a limit of approximately
4
Hz.
FM Accuracy
at
10 kHz
Rate
3. Connect the Modulation Analyzer's CALIBRATE AM/FM OUTPUT to the INPUT. (See
Figure
4-2.)
NOTE
For greatest accuracy, allow the Modulation Analyzer to warm up for at
least one-half hour.
4.
On the ,Modulation Analyzer, press CALIBRATE. Allow at least two readings (approximately
40
seconds) to pass
.
The display should read between 99 and 101%. Record this value for future
reference.
FM Calibration Factor;
40
kHz Modulation Range: 99
101%
4-10
Performance Test 2