Simple CAT Test Set
Construct a test set to control, program or verify the operation of a CAT Repeater Controller. The circuit consists of a toggle switch to simulate COR and a LED to display a PTT indication. The DTMF pad on the telephone generates the tones and simulates receiver audio input to the controller. All voice synthesizer responses and courtesy and warning tones are heard in the telephone's handset. COR is active high so set the controller's dip-switch #1 to the OFF position. It is important that the DC supply to the controller is +12 volts as this voltage provides bias for the telephone's DTMF pad.