Microphone Line Input Level; Deviation Mode); Mute Threshold Setting; Table 7-2 Nominal Deviation - RELM BK RADIO SDMX920 Technical Manual

Technical Manual
7.1.11 Microphone Line Input Level (Nominal Deviation
Or Peak Deviation Mode)
The required nominal deviation or Peak deviation is dependent on whether the radio is
narrow or wide. The following table lists the required level for each case:
Bandwidth
Narrow (12.5kHz spacing)
Wide (25kHz spacing)
The radio is defaulted to work in this Nominal mode. The radio also can operate in a
peak deviation mode. To change mode use the built in menu system. Configuration
Menu --Software Switch Configuration Menu-- Nominal / Peak deviation .

7.1.12 Mute Threshold Setting

Test Equipment:
♦
PC with Terminal software
♦
RF Communications test set
♦
+13.8VDC power supply
MX920 Testing – Rx Mute:
1. Monitor the low level muted RX VF (pin1 of RJ45) with RF Communications test
set. Inject the correct RF frequency into the receiver for the test channel Set the
test set to measure SINAD and reduce the RF generator until 8db SINAD is
reached.
2. Adjust the front panel potentiometer (Mute control) so that the RX just goes into
the muted condition.
Further information on setting mute (squelch) can be found in Section 1.1.1
© SPECTRA ENGINEERING 2003 Revision 1.1.4
FM Nominal
Deviation (kHz)
1.5
3.0

Table 7-2 Nominal Deviation

Installation and Operation
FM Peak
Deviation (kHz)
2.4
4.8
31