The System regulator modules provide voltage regulation, system metering and audio monitoring for the MT-3 or MT-4 Radio System. The System regulator includes a +9.5 VDC high current (5A) voltage regulator with an anti-latch hysteresis circuit. Selected options can include antenna relay drivers, front panel switch selectable meter outputs to check supply voltages, carrier strengths, etc, and audio amplifier and loudspeaker.

A rotary switch on the front panel allows the various functions to be selected for monitoring. Two front panel jacks are provided for monitoring of selected functions. An audio amplifier and loudspeaker allow for audio monitoring. Front panel controls allow for audio volume adjustment and for selecting audio from receivers A or B, or turning the audio circuits off reducing power consumption. A LED indicator illuminates when the audio circuits are on. A front panel switch enables PTT on both transmitters for testing.