Motorola GM338 Service Manual page 34

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