
5. Log Amplifier Adjustments
Procedure
1. Position the spectrum analyzer upright as shown in Figure 3-33.
Remove the IF-Display section top cover.
2. Set spectrum analyzer LINE switch to ON and press
(2-22).
Offset
Adjustment
3. Key in
FREQUENCY
SPAN] 0 Hz,
CCENTER
FREQUENCY) 7.6 MHz,
Check
(REFERENCE LEVEL_) + 10
dBm,
(jREs)
10
kHz,
and press LIN
pushbutton.
4. Connect DVM to A4AlTPl and DVM ground to the IF casting.
Connect the frequency synthesizer to the RF INPUT. Key in
cm)
80 MHz and
c-1
-86.98
dBm.
The frequency
synthesizer provides a
5OQ
load to the spectrum analyzer RF
INPUT.
5. Check
A4A2R79
ZERO for a DVM indication of 0.0000 f0.0005 V
dc. See Figure 3-34 for location of adjustment. If
A4A2R79
ZERO
requires adjustment, perform Adjustment Procedure 6, “Video
Processor Adjustment” before continuing.
R79
R6
1
R91
RI4
R62
ZERO
ATTEN
-12 VTV LG 20
A4A3
A4A2
IFIER-
OR
R18
/
A4A3
Figure 3-34. Location of Log Amplifier Adjustments
3.70 Adjustments
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