Delay Compensation - HP 83522A Service Notes

Model 83522A Adjustments
ADJUSTMENTS
5-1 7.
FREQUENCY ACCURACY (Cont'd)
5 0 MHz Marker Accuracy Check
24. Press
mrxrr
and 50 MHz should be displayed.
Press
'W
4
26. Adjust
mpi\iTwT
control so the
m M m
lamp lights.
27. Press
%kTaT ' T
and 1.200 GHz should be displayed. The external frequency
counter should read 1.200 GHz 315 MHz. This indicates that the Frequency Accuracy
Adjustments have been properly performed.
5-1 8. DELAY COMPENSATION
REFERENCE:
Performance Test: 8350A Paragraph 4-13.
Service Sheet: A7
DESCRIPTION:
This circuit compensates for the delay in the RF sweep output that occurs at faster sweep
speeds. The Frequency Calibration procedure is first done to ensure that the proper
frequencies are referenced during the adjustment procedure. An 8350A amplitude marker is
used as the frequency reference (which will not change as sweep time is modified). At a slow
(0.5 second) sweep time, the 8350A amplitude marker is set adjacent to an 83522A 50 MHz
crystal marker at the frequency of interest Sweep time is then decreased to 10 milliseconds
and delay in the YO is observed as a shift in the spacing bemeen the 8350A amplitude
marker and the 83522A crystal marker. At sweep speeds faster than 100 milliseconds, delay
should not exceed +5 MHz (the difference between CW and Swept Frequency accuracies).
EQUIPMENT:
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Sweep Oscillator. HP 8350A
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Digital Voltmeter. HP 3455A
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Oscilloscope HP 1740A