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

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WJ-8711A DIGITAL HF RECEIVER MAINTENANCE
7-13
13. Set the distortion analyzer function control and meter range to the SET
LEVEL positions. Adjust the distortion analyzer sensitivity control for a
100% indication on the meter.
14. Set the distortion analyzer function control to the Distortion position. Slowly
adjust the distortion analyzer Frequency control for a minimum indication on
the meter. Reset the meter range as required for the best meter resolution.
Verify that the total harmonic distortion measured does not exceed 5%.
7.6.8
SQUELCH/MUTE PERFORMANCE TEST
1. Connect the WJ-8711A Receiver and test equipment as illustrated in
Figure 7-7 .
OSCILLOSCOPE RECEIVER
SQUELCH
TB1
2031
SIGNAL
GENERATOR
RF IN RF OUT
A3J1
HEADPHONE
87IL38
Figure 7-7. Squelch/Mute Performance Test Equipment Connection
2. Set the WJ-8711A Receiver as follows:
Tuned Frequency: 15.000000 MHz FRQ 15 <Return>
Detection Mode: AM DET 1 <Return>
IF Bandwidth: 6.0 kHz BWS 4 <Return>
Gain Mode: AGC Fast AGC 2 <Return>
RF Input Path Normal RFP 1 <Return>
Squelch: -120 SQL 120 <Return>
3. Set the signal generator to produce a 15.0000 MHz CW output at a level of
-130 dBm.
4. Observe that a steady logic "1" level (+5V) is present at the Squelch terminal
of the rear panel terminal bus (TB1), as indicated on the oscilloscope.
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