HP 8566B Adjustment Manual page 336

2 1. Frequency Response Adjustments
3-196 Adjustments
the high end of the band drop in amplitude by approximately
0.75 dB.
126. Readjust 22-turn (IF Offset) potentiometer A6A12R83 D as
necessary to maximize the overall level of the displayed signal
responses from 12.5 GHz to 18.6 GHz on the spectrum analyzer
display. If the displayed signal responses peak at widely different
settings of A6A12R83 D, perform the following steps:
a. Adjust 22-turn (YTX Linearity) potentiometers A6AlOR41
LB2, A6AlOR42 LB3, A6AlOR70 LB4, A6A610R34 LR2,
if they have not already been so adjusted; do
b. Readjust 22-turn (IF Offset) potentiometer A6A12R83 D as
necessary to maximize
responses at the low end of the band.
c. On the spectrum analyzer, key in MARKER (j-1 and
position the marker at the point in the band where the signal
responses begin to fall off from their maximum value.
d. Adjust 22-turn (YTX Linearity) potentiometer A6AlOR41 LB2
clockwise until the displayed signal responses at the high end
of the band begin to drop. Continue to adjust A6AlOR41 LB2
until the rolloff point aligns with the position of the marker.
See Figure 3-90 for the location of A6AlOR41 LB2, A6AlOR42
LB3, A6AlOR34 LR2 and A6AlOR37 LR3.
e. Readjust 22-turn (YTX Linearity) potentiometer A6AlOR34
LR2 clockwise to maximize the displayed signal responses for
approximately 3 divisions to the right of the marker.
f. On the spectrum analyzer, key in MARKER [NORMAL) and
position the marker at the point in the band where the signal
responses begin to fall off from their maximum value.
g. Readjust 22-turn (YTX Linearity) potentiometer A6AlOR42
LB3 clockwise until the displayed signal responses at the high
end of the band begin to drop. Continue to adjust A6AlOR42
LB3 until the rolloff point aligns with the position of the
marker.
h. Readjust 22-turn (YTX Linearity) potentiometer A6AlOR37
LR3 clockwise to maximize the displayed signal responses at
the high end of the band.
i. Readjust A6A12R83 D, A6AlOR34 LR2, and A6AlOR37 LR3
as necessary to maximize the displayed signal responses from
12.5 GHz to 18.6 GHz on the spectrum analyzer display.
127. Gradually readjust (Band D Lower Segment) A6AllR57 Dl
and (Band D Upper Segment) A6AllR75 D2 as necessary for
maximum flatness of the displayed signal responses.
128. On the spectrum analyzer, key in SWEEP
129. Press SWEEP CRINGLE] on the spectrum analyzer and wait for the
sweep to complete (150 seconds) and the SWEEP LED to turn
off. As the spectrum analyzer tunes from 12.5 GHz to 18.6 GHz,
the spectrum analyzer frequency response should be displayed as
TRACE B.
the overall level of the displayed signal
5, m).
not readjust
)
SWEEP TIME