HP 8559A Operation And Service Manual page 49

MODEL 8559A
4-14. NOISE SIDEBANDS (Cont'd)
Comb Generator:
COMB FREQUENCY
INTERPOLATION AMPLITUDE
OUTPUT AMPLITUDE
Connect equipment as shown in Figure 4-8.
Adjust TUNING control to locate 1.8-GHz comb tooth on CRT
Adjust REFERENCE LEVEL and REF LEVEL FINE controls to position peak of 1.8-GHz signal at top
graticule line.
Decrease FREQ SPAN/DIV to 20 kHz and RESOLUTION BW to 1 kHz. Adjust TUNING as necessary
to keep signal centered.
Position signal at center of display. Set VIDEO FILTER control fully clockwise (not in MAX detent
position). Measure noise sidebands existing more than 1.5 divisions (30 kHz) from 1.8-GHz signal. Noise
sidebands should be more than 70 dB (7 divisions) down from top graticule line.
PERFORMANCE TESTS
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1 MHz
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PERFORMANCE TESTS
100 MC
OFF
Full clockwise
div. down