RT9080 Repeater

A full duplex repeater can be made by connecting two RT9080 E&M radios back to back using a repeater cable, part no: 119-47-348.
Functionality

Transmit 4W audio is on pins 4 and 12 of the DB-15 connector

Receive 4W audio is on pins 3 and 10. The Rx and Tx audio levels in the cable between the radios are 1VPP at 3.5 kHz deviation.

Receive COR of one radio activates the ‘M’ relay which places a ground on pin 2 of the DB15 of the other radio (Tx key).