General

The ATC transponders, TCAS, and the DME interrogators operate in the same frequency band. There is a suppression interface between these units. This prevents damage to the receiver circuits during a signal transmission. The suppression circuits also prevent responses from onboard equipment. The first unit to transmit sends a suppression pulse to a coax tee. The coax tee divides the suppression pulse and sends it to the different units, or to a different coax tee. This suppression pulse prevents the operation of the receiver circuits in the other units.