Motorola MTX450 Suplemento ao Manual de Serviço Básico - Página 28
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4-4
Test Name
Reference
Mode: PWR MON
Frequency
4th channel test frequency*
Monitor: Frequency error
Input at RF In/Out
Rated Audio
Mode: GEN
Output level: 1.0mV RF
4th channel test frequency*
Mod: 1kHz tone at
3kHz deviation
Monitor: DVM: AC Volts
Distortion
As above, except to distor-
tion
Sensitivity
As above, except SINAD,
(SINAD)
lower the RF level for 12dB
SINAD.
Noise
RF level set to 1mV RF
Squelch
Threshold
(only radios
with conven-
tional sys-
tem need to
As above, except change fre-
be tested)
quency to a conventional
system. Raise RF level from
zero until radio unsquelches.
* See Table 4-4 of Basic Service Manual 68P80906Z54 for Test Frequencies.
Table 4-1.
Receiver Performance Checks
Service Monitor
Radio
Test Set
TEST MODE,
PTT to continu-
Test Channel
ous (during the
4 carrier
performance
squelch out-
check)
put at
antenna
TEST MODE
PTT to OFF
Test Channel
(center), meter
4 carrier
selector to
squelch
Audio PA
As above
As above
As above
PTT to OFF
(center)
As above
PTT to OFF
(center), meter
selection to
Audio PA,
speaker/load to
speaker
out of TEST
As above
MODE; select
a conven-
tional system
Transceiver Performance Testing
Comments
Frequency error to be
±600 Hz UHF
Set volume control to
3.16Vrms
Distortion 3.0%
Typical
RF input to be
0.25µV
Set volume control to
3.16Vrms
Unsquelch to occur at
<0.25µV.
Preferred SINAD =
8dB