Midian Electronics’ TRE-4 is a tone remote encoder/decoder with a 600 ohm line driver, which encodes the high level 2175 Hz, F1-F8 function tone and continuous low-level 2175 Hz guard tone and passes received audio via a dedicated phone line, telemetry link or microwave to a tone remote adaptor to key a base station or repeater. The TRE-4 will also pass audio from an audio source to the tone remote adaptor via the above mentioned link.

To create a simple tone remote desk set, Midian’s TRE-4 has a built in 3.5mm audio jack for connection to a powered external speaker and an RJ50 jack for connection to many popular desk mics.