Mhz Filter Switch Adjustment, Test Setup - Watkins-Johnson Company WJ-8718-19/FE Instruction Manual

MAINTENANCE
WJ-8718-19/FE HF RECEIVER
3.6.3.2 10.7 MHz Filter Switch, A4A1, (791594) Adjustment
1. Deenergize the receiver.
2. Connect the test equipment as shown in Figure 4-3.
Set the Generator for 15.005 MHz, unmodulated, at
-64 dBm.
SIGNAL
GENERATOR
RF
OUT
2
O
HF RECEIVER
RFIN
OA2J1
A4AITP2
s
o
J_
RF VOLTMETER
INPUT
9
O
>-Q-
50 SL
RFPROBE
Figure 4-3. 10.7 MHz Filter Switch Adjustment, Test Setup
4-66
3.
4.
5.
6.
Remove A4A1 and A4A2 boards.
Place A4A1 on an extender card.
Energize the receiver and tune to 15.00500 MHz.
Select the 3.2 kHz IF Bandwidth position and adjust
A4A1R26 for a -36 dBm (3.5 mV) RF Voltmeter reading.
NOTE
If -36 dBm cannot be obtained, adjust
for maximum dBm reading. Record this
reading.