HP 8566B Adjustment Manual page 339

SWEEP TIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 ms
SWEEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONT
148. On the spectrum analyzer, key in TRACE A
analyzer completes each sweep, a series of approximately 23 new
responses should be displayed. The peaks of these responses
coarsely outline the spectrum analyzer frequency response.
149. Gradually adjust (Band E Lower Segment) A6AllR60 El and
(Band E Upper Segment) A6AllR78 E2 for maximum flatness of
the displayed signal responses. The adjustments are interactive,
with A6AllR60 El having the most effect on the level of the
displayed signals below mid-band (approximately 20.3 GHz),
and A6AllR78 E2 having the most effect on the level of
the displayed signals above mid-band. Adjust A6AllR60 El
counterclockwise to increase the level of the displayed signal
responses below mid-band. Adjust A6AllR78 E2 clockwise
to increase the level of
mid-band. See Figure 3-90 for the locations of A6AllR60 El and
If the displayed signals at the high end of the band drop off by more
than 3-4 dB, center A6AllR78 E2 and proceed to step 150.
150. On the spectrum analyzer, key in
C
1 dB, TRACE B (VIEW), IsAvE_) 4, C-1 2s,
ENTER
TRACE B [BLANK), (HOLD].
151. Readjust 17-turn (YTX Diode Bias) potentiometer A6AlOR95 VE
to maximize the overall level of the displayed signal responses
from 18.6 GHz to 22.0 GHz on the spectrum analyzer display.
Then, adjust A6AlOR95 VE clockwise until signal responses at
the high end of the band drop in amplitude by approximately 1.5
152. Readjust 22-turn (IF Offset) potentiometer A6A12R82 E as
necessary to maximize the overall level of the displayed signal
responses from 18.6 GHz to 22.0 GHz on the spectrum analyzer
display. If the displayed signal responses peak at widely different
settings of A6A12R82 E, perform the following steps:
a. Adjust 22-turn (YTX Linearity) potentiometers A6AlOR70 LB4
and A6AlOR76 LR4 fully counterclockwise if they have not
already been so adjusted;
LR2, or A6AlOR37 LR3.
b. Readjust 22-turn (IF Offset) potentiometer A6A12R82 E as
necessary to maximize the overall level of the displayed signal
responses at the low end of the band.
c. 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.
d. Readjust 22-turn (YTX Linearity) potentiometer A6AlOR70
LB4 clockwise until the displayed signal responses at the high
end of the band begin to drop. Continue to adjust A6AlOR70
LB4 until the rolloff point aligns with the position of the
2 1. Frequency Response Adjustments
[
CLEAR
the displayed signal responses above
[ )
SWEEP TIME
do not readjust A6A12R40 LBl,
- ),
WRITE
Adjustments 3-l 99