Receiver Performance Tests; Table 4-5: Receiver Performance Checks - Motorola HT750 - UHF/VHF/Low Band - Radio Service Manual

Transceiver Performance Testing
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
Test Name
Reference
Frequency 4th channel test frequency*
Monitor: Frequency error
Rated Audio
Output level: 1.0mV RF
4th channel test frequency*
Monitor: DVM: AC Volts
Distortion As above, except to distor-
Sensitivity As above, except SINAD,
(SINAD) lower the RF level for 12dB
Noise RF level set to 1mV RF
Squelch
Threshold
(only radios
with conven-
tional sys-
tem need to
As above, except change
be tested)
frequency to a conventional
system. Raise RF level from
zero until radio unsquelches.
* see Table 4-4
° ( °
F 25 C) and in conventional or trunked models.

Table 4-5: Receiver Performance Checks

Service Monitor
Mode: PWR MON
Input at RF In/Out
Mode: GEN
Mod: 1 kHz tone at
3 kHz deviation
tion
SINAD.
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
4-7
Comments
Frequency error to be
±200 Hz VHF
±600 Hz UHF
±60 Hz Low Band
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 =
9-10dB