Watkins-Johnson Company WJ-8711A, Installation, Operation And Maintenance Manual

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MAINTENANCE WJ-8711A DIGITAL HF RECEIVER
7-6
2. Set Signal Generator #1 to produce a 30.0000 MHz CW signal at an output
level of -80 dBm.
3. Set the WJ-8711A Receiver as follows:
Tuned Frequency: 30.000000 MHz FRQ 30 <Return>
Detection Mode: CW DET 3<Return>
BFO Offset: +1.00 kHz BFO 1000 <Return>
IF Bandwidth: 6.0 kHz BWS 4 <Return>
Gain Control: AGC Slow AGC 1 <Return>
Squelch: Off SQL 136 <Return>
4. Set the Frequency Counter for 0.1 Hz resolution.
5. Note the frequency displayed on the Frequency Counter to determine the
accuracy of the receiver timebase. The displayed frequency should fall in the
range between 980.0 and 1020.0 Hz.
6. Set Signal Generator #2 to produce a 10.0000 MHz CW signal at an output
level of 0 dBm. Connect the Signal Generator output to the EXT. REF.
connector at the receiver rear panel (A3J3).
7. Note the frequency displayed on the frequency counter. This frequency
should be approximately 1000 Hz, depending on the accuracy of the
frequency setting in step 2.
8. While observing the frequency counter display, slowly increase and decrease
the frequency of generator #2. Verify that the frequency displayed on the
frequency counter changes with changes in the generator frequency,
indicating that the receiver timebase is locked to the external reference.
NOTE
The magnitude of change on the frequency counter does
not match the generator changes due to frequency scaling
within the receiver.
7.6.4
FINE TUNING ACCURACY
1. Connect the WJ-8711A Receiver and test equipment as illustrated in
Figure 7-4 .
FLUKE 1953A
FREQUENCY
COUNTER
RECEIVER
LINE A +
HP-8640B
SIGNAL
GENERATOR
#1
RF IN RF OUT
A3J1 AUDIO -
87IL35
Figure 7-4. Fine Tuning Accuracy Performance Test Equipment Connection
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