Motorola GP1280 Series, Basic Service Manual

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Chapter 4
PERFORMANCE TESTING
1.0 Introduction
The receiver and transmitter performance tests are contained in Tables 4-1 and 4-2 respectively.
Refer to Chapter 5 for the test equipment set up. Note that all test measurements are taken at 25°C.
2.0 Receiver Performance Tests
The receiver performance tests are described in Table 4-1 below.
Table 4-1
Receiver Performance Checks
Test Name
Communications
Analyzer
Radio Test Set Comments
Reference
Frequency Mode: PWR MON
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
±
200Hz VHF
±
600Hz UHF
Rated Audio Mode: GEN
Output level: 1.0mV RF
Mod: 1kHz tone at
3kHz deviation
Monitor: DVM: AC Volts TEST MODE
Test Channel
4 carrier
squelch PTT to OFF
(centre), meter
selector to
Audio PA Set volume control to
3.16Vrms
(GP320/340/360/380)
3.46Vrms
(GP344/388)
Distortion As above, except to
distortion As above As above Distortion 3.0%
Typical
Sensitivity
(SINAD) As above, except SINAD,
lower the RF level for 12dB
SINAD. As above PTT to OFF
(center) RF input to be
0.25
µ
V
<0.35
µ
(GP344/388)
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
(GP320/340/360/380)
3.46Vrms
(GP344/388)
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