
10. Step Gain and 18.4 MHz Local Oscillator Adjustments
0.1
dB
Gain
Step
34.
Adjustment
35.
36.
37.
18.4
MHz
Local
38.
Oscillator
Adjustment
39.
40.
Key in LIN,
ISHIFT)
* [AUTO) (resolution bandwidth), and
(REFERENCE LEVEL] -19.9
dBm.
Set step attenuators to 13
dB.
Press
MARKER
[nl
twice to establish a new reference.
Key in (REFERENCE LEVEL] -18.0
dBm.
Set step attenuators to 11
dB.
Adjust
A4A5R51
VR for MKR A level of
+O.lO
dB.
See Figure 3-49
for location of adjustment.
Remove all test equipment from the spectrum analyzer. Connect
CAL OUTPUT to RF INPUT.
Press
(2-22]
and
IRECALL)
@.
Set front-panel FREQ ZERO control to midrange.
Adjust
A4A5ClO
FREQ ZERO to peak signal trace on CRT. See
Figure 3-49 for location of adjustment.
A4A5
STEP GAIN
R2
Cl0
FREQ
R51
+lOV
ADJ
RlO
ZERO COARSE
C9
VR
A4A5
Figure 3-49.
Location of
.l
dB Gain Step, 18.4 MHz LO, and +
1OV
Adjustments
41. Key in (FREQUENCY SPAN] 1
kHz,
l-j-j]
100 Hz, and
(PEAK
SEARCH] [a.
42. Adjust front-panel FREQ ZERO control fully clockwise. Press
CPEAK
SEARCH]. Signal should move at least 60 Hz away from
center CRT graticule line.
43. Adjust front-panel FREQ ZERO control fully counterclockwise.
Press (PEAK SEARCH). Signal should move at least 60 Hz away from
center CRT graticule line.
44. If proper indications are not achieved, increase or decrease value
of
A4A5C9
and repeat adjustment from step 33. Refer to
‘Iable
3-3 for range of values.
45. Press
@?XiGj
and (RECALL)
@.
46. Adjust front panel FREQ ZERO for maximum amplitude of the
displayed signal trace.
3-99 Adjustments
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