DRS WJ-8611, Инструкция по установке, эксплуатации и обслуживанию

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WJ-8611 DIGITAL VHF/UHF RECEIVER
6-12 MAINTENANCE
2. Set the receiver as follows:
Tuned Frequency 250.00000 MHz
Detection Mode AM
IF BW 5 kHz
Gain Control AGC Fast
Squelch Off
3. Set the signal generator as follows:
Frequency 250.0000 MHz
Output Level -106 dBm
Modulation AM, 50%, 400 Hz
4. Note the video level on the voltage level displayed on the AC
voltmeter. The output level should range from 0.25 to 0.50 Vrms.
Note the video level indication on the dB scale of the AC voltmeter
as a reference.
5. While observing the video level on the AC voltmeter, increase the
signal generator output level, in 10 dB increments, until an output
level of -16 dBm is reached (90 dB change). Note the video signal
level at each 10 dB increase in level.
6. Verify that the video amplitude varies by no more than
±
3 dB
throughout the 90 dB increase in the RF input signal level.
6.7 WJ-8611 MODULE PERFORMANCE TESTS
The module test procedures in this section assist in isolating a fault to a
malfunctioning module or subassembly. These procedures should only be
performed if the receiver test procedures in
paragraph 6.6 fail to provide
the specified results. In performance of these tests, remove the top and
bottom covers of the receiver to gain access to the internal circuitry. The
Digital Control PC Assembly (A2) contains configuration data
programmed in EEPROM that is vital for the proper operation of the 1st
LO/1st Converter PC Assembly (A3A1). If it is determined that
replacement of the Digital Control PC Assembly (A2) or the 1st LO/1st
Converter PC Assembly (A3A1) is required, contact the factory
before
replacement is attempted.
!
CAUTION The test procedures in this section should only be
performed by skilled technicians who are thoroughly
familiar with fault isolation and repair of electronic
equipment.
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