HP 8901B Operation And Calibration Manual page 259

Operation
Model 8901B
Front-Panel Key
Special Function Code
or
Measurement
Mode
Action:
FM Calibration
Factor
Enter the appropriate front-panel key
or
special function code
to
manipulate the FM Calibration Factor
as described in the following table:
Program Code
e
Disable
Enable
Display
Any
17.0 SPCL 17.0SP
sc
FM
(Blue Key)
(From CALIBRATE
mode)
SAVE CAL
Any
17.1
SPCL 17.1SP
Yo
CAL FACTOR'
FM
Any
17.2
SPCL 17.2SP
CF
(Blue Key)
Calibrating
or
Cross Checking Another HP 8901
or
8902 RF Signal Analyzer
To compute an FM calibration factor for another RF signal analyzer that
has
no internal calibrator,
or that has an internal calibrator that is to be cross checked, use the Modulation Analyzer and its
calibrator as follows:
1. Connect the Modulation Analyzer's CALIBRATION AM/FM OUTPUT
to
the RF input of the
other RF signal analyzer.
2. Key in 12.0 SPCL into the Modulation Analyzer. Record the value that appears in the display.
This is the computed, calibrated, peak FM deviation (excluding noise).
3. Key in 12.1 SPCL into both instruments. Record the value that appears on the display of the
RF
signal analyzer.
(If
display jitter makes readings difficult, key in 5.1 SPCL.) The displayed value is
the weighted, peak, residual FM deviation of the calibrator's unmodulated output as demodulated
by the RF signal analyzer.
4. Key in
12.2 SPCL for both instruments. Record the value that appears on the display of the
RF signal analyzer.
(If
display jitter makes readings difficult, select 5.1 SPCL.) The displayed
value is the demodulated, positive, peak FM deviation of the calibrator's modulated output
(including noise).
5. On the RF signal analyzer, select PEAK-. Note the value displayed on the
RF signal analyzer. If
the difference between the results of steps 4 and 5 is three counts or less in the least significant
digit, an average between the two need not be computed; use the result from step
4.
If
the difference
between the two readings is greater than three counts in the least significant digit, compute the
average as follows:
(result
of
step
4)
+
(result of step 5)
2
(12.2 result) =
6. Compute the FM calibration factor of the RF signal analyzer as follows:
(12.2 result) - (12.1 result)
(12.0 result)
F M Calibration Factor (%)
=
100
x
7.
TO use this FM calibration factor to correct FM measurements made with the RF signal analyzer,
enter the value as a ratio reference and use the Ratio function in the RF signal analyzer.
3-156
FM Calibration