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MDS 4790M (MPT 1411) I/O Guide
MDS 05-3628A01, Rev. B
Invisible place holder
Figure 15. Alarm Relay Connections
4-Wire Audio Connector
J2 is a plug-in terminal strip that provides connections for 4-wire audio circuits.
Figure 16 shows the function of each terminal as viewed from the rear panel.
Terminals 1 and 2 are for transmit audio input with a nominal 600
Ω
impedance. Terminals 3 and 4 provide a receive audio output with a nominal
600
Ω
impedance. Pins 5 and 6 provide a source for an external keying source.
Connecting pins 5 and 6 together keys the radio.
Figure 16. 4-Wire Audio Connections
4.7 Post Installation Checks
Before applying power to the radio, verify that:
• All connections are properly wired and secure
• Input voltage matches that of the installed power supply
• Antenna heading is preset in the direction of the associated station.
This completes the installation of the radio. Section 5.0,
START-UP AND
OPERATION
, describes the unit’s indicators and gives initial startup procedures.
