HP 8566B Adjustment Manual page 332

2 1. Frequency Response Adjustments
101. Readjust 22-turn (IF Offset) potentiometer A6A12R84 C as
necessary to maximize the overall level of the displayed signal
responses from 5.8 GHz to 12.5 GHz on the spectrum analyzer
display. If the displayed signal responses above mid-band drop
off in amplitude and peak at a different setting of A6A12R84 C
perform the following steps:
a. Perform step 51 if it has not already been performed.
b. Readjust 22-turn (IF Offset) potentiometer A6A12R84 C to
maximize the displayed signal responses at the low end of the
band.
c. Key in MARKER @Z!ZiJ 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 A6AlOR40 LB1
clockwise until the displayed signal responses at the high end
of the band begin to drop. Continue to adjust A6AlOR40
LB1 until the rolloff point aligns with the position of the
marker. See Figure 3-90 for the locations of A6AlOR40 LB1
and A6AlOR31 LRl.
e. Readjust 22-turn (YTX Linearity) potentiometer A6AlOR31
the high end of the band.
f. Readjust A6A12R84 C and A6AlOR31 LRl as necessary to
maximize the displayed signal responses from 5.8 GHz to 12.5
102. Gradually readjust (Band C Lower Segment) A6AllR54 Cl
and (Band C Upper Segment) A6AllR72 C2 as necessary for
maximum flatness of the displayed signal responses.
103. On the spectrum analyzer, key in SWEEP
104. Press SWEEP [ml 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 5.8 GHz to 12.5 GHz,
the spectrum analyzer frequency response should be displayed as
TRACE B, as shown in Figure 3-98.
the displayed signal responses at
5, (HOLD).
]
SWEEP TIME