Motorola HT1250, Руководство по обслуживанию

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Transceiver Performance Testing 4-7
4.4 Receiver Performance Tests
The receiver and transmitter performance tests are contained in Table 4-5 and Table 4-6 respectively.
Refer to Chapter 5, Figure 5-1 on page 5-2, for test equipment setup. Note that all test measurements
are taken at 77
°
F
(
25
°
C) and in conventional or trunked models.
Table 4-5: Receiver Performance Checks
* see Table 4-4
Test Name Service Monitor Radio Test Set Comments
Reference
Frequency
Mode: PWR MON
4th channel test frequency*
Monitor: Frequency error
Input at RF In/Out
TEST MODE,
Test Channel
4 carrier
squelch out-
put at
antenna
PTT to continu-
ous (during the
performance
check)
Frequency error to be
±200 Hz VHF
±600 Hz UHF
±60 Hz Low Band
Rated Audio Mode: GEN
Output level: 1.0mV RF
4th channel test frequency*
Mod: 1 kHz tone at
3 kHz 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
3.16Vrms
Distortion As above, except to distor-
tion
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
Noise
Squelch
Threshold
(only radios
with conven-
tional sys-
tem need to
be tested)
RF level set to 1mV RF As above PTT to OFF
(center), meter
selection to
Audio PA,
speaker/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 conven-
tional system
As above Unsquelch to occur at
<0.25
µ
V.
Preferred SINAD =
9-10dB