While external suppression should be connected when a GTX-327 is installed into an aircraft with a DME, the GTX-327 suppression input/output is not compatible with the Bendix/King KN-62, KN-64, and KNS-80. These DMEs have an output only suppression port and can be damaged by the GTX-327 mutual suppression output. Therefore, the suppression pin should be left open. If the suppression line is connected between the GTX-327 and above King DME units then the DME will appear to be inoperative, display will be blank and will not transmit.