Abstract: Disclosed is an audio-to-radio and radio-to-audio signal converter and method for interfacing a facsimile machine with a radio transmitter-receiver having a microphone input, an audio output and a push-to-talk relay. The converter provides a first circuit for inputting the output signal of a facsimile machine to the microphone input of a radio transmitter-receiver; a second circuit controlled by the output signal of the facsimile machine for operating the push-to-talk relay of the radio transmitter-receiver; and a third circuit connected to the audio output of the transmitter-receiver for amplifying the audio output signal, and inputting the resultant signal to the facsimile machine. A fourth circuit provides a null feedback that keeps the stronger audio signals from being amplified which may trigger the push-to-talk relay.