
2 1. Frequency Response Adjustments
101.
102.
103.
104.
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
LRl
clockwise to maximize the displayed signal responses at
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
GHz
on the spectrum analyzer display.
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.
On the spectrum analyzer, key in SWEEP
C@iKEJ
(SWEEP TIME]
15Os,
TRACE A (BLANK], TRACE B
[MAXHOLD),
m
6, TRACE B
(CLEAR-WRITE),
m
5, (HOLD).
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.
3-l
92 Adjustments
Comentários a estes Manuais