Motorola GM140, Базовое руководство по обслуживанию

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4-6 TRANSCEIVER PERFORMANCE TESTING
Table 4-6 Receiver Performance Checks
* See Table 4-4
Test Name
Communications
Analyzer
Radio Test Set Comment
Reference
Frequency Mode: PWR MON
4th channel test frequency*
Monitor: Frequency error
Input at RF In/Out TEST MODE,
Test Channel 4
carrier squelch
output at
antenna PTT to
continuous
(during the
performance
check) Frequency
error to be
±150 Hz VHF
±150 Hz UHF
±150 Hz LB
Rated Audio Mode: GEN
Output level: 1.0mV RF
4th channel test frequency*
Mod: 1kHz tone at
3kHz deviation
Monitor: DVM: AC Volts TEST MODE
Test Channel 4
carrier squelch PTT to OFF
(center), meter
selector to
Audio PA Set volume
control to
8.12Vrms
Distortion As above, except to
distortion As above As above Distortion
<5.0%
Sensitivity
(SINAD) As above, except SINAD,
lower the RF level for 12dB
SINAD. As above PTT to OFF
(center) RF input to be
<0.3
µ
V
Noise Squelch
Threshold
(only radios
with
conventional
system need
to be tested) RF level set to 1mV RF As above PTT to OFF
(center), meter
selection to
Audio PA,
spkr/ load to
speaker Set volume
control to
3.16Vrms
As above, except change
frequency to a conventional
system. Raise RF level from
zero until radio unsquelches. out of TEST
MODE; select
a conventional
system As above Unsquelch to
occur at
<0.25
µ
V.
Preferred
SINAD =
9-10dB