HP 8566B Adjustment Manual page 335

the displayed 15.0 GHz signal. Adjust 17-turn (Band D Step
Gain) potentiometer A6AlOR27 GD as necessary to adjust the
amplitude of the displayed 15.0 GHz marker to -10.00 dBm
fO.10 dB. Adjust A6AlOR27 GD counterclockwise to increase
the signal level, and clockwise to decrease the signal level.
If A6AlOR27 GD does not have sufficient range, adjust the
amplitude of the displayed 15.0 GHz marker as close as possible
to -10.00 dBm. See Figure 3-90 for the location of A6AlOR27
GD.
119. On the spectrum analyzer, key in LOG SCALE
120. Readjust 22-turn (IF Offset) potentiometer A6A12R83 D as
necessary to maximize the amplitude of
the spectrum analyzer display.
121. Set the synthesized sweeper controls as follows:
START FREQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12.5 GHz
STOP FREQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18.6 GHz
RF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . on
LEVELING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . XTAL
SWEEP TIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 ms
SWEEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONT
122. On the spectrum analyzer, key in TRACE A
( )
SWEEP TIME
analyzer completes each sweep, a series of approximately 22 new
responses should be displayed, as shown in Figure 3-98. The
peaks of these responses coarsely outline the spectrum analyzer
frequency response.
123. Gradually adjust (Band D Lower Segment) A6AllR57 Dl and
(Band D Upper Segment) A6AllR75 D2 for maximum flatness of
the displayed signal responses. The adjustments are interactive,
with A6AllR57 Dl having the most effect on the level of
the displayed signals below mid-band (approximately 15.5
the displayed signals above mid-band. Adjust A6AllR57 Dl
counterclockwise to increase the level of the displayed signal
responses below mid-band. Adjust A6AllR75 D2 clockwise
to increase the level of the displayed signal responses above
mid-band. See Figure 3-90 for the locations of A6AllR57 Dl and
If the displayed signals at the high end of the band drop off by more
than 2-3 dB, center A6AllR75 D2 and proceed to step 125.
124. On the spectrum analyzer, key in
[
1 dB, TRACE B [VIEW), (SAVE) 4, c-1 2s,
ENTER
TRACE B [BLANK), [ml.
125. Readjust 17-turn (YTX Diode Bias) potentiometer A6AlOR12 VD
to maximize the overall level of the displayed signal responses
from 12.5 GHz to 18.6 GHz on the spectrum analyzer display.
Then, adjust A6AlOR12 VD clockwise until signal responses at
2 1. Frequency Response Adjustments
(
ENTER
the 15.0
[
CLEAR
)
TIME
Adjustments 3-195
2
- ),
WRITE