Motorola CDM1250, Basic Service Manual

Page: 42 / 92

3-8 Transceiver Performance Testing
* See Table 3-4
Table 3-7: Receiver Performance Checks
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
±100 Hz LowBand
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