wer to the 28VDC IN NO 2 pin of the CTI.-92E control unit. CTL-92E Transponder Control Unit The transponders) TDR-94D(s) are controlled by a single Rockwell Collins CTL-92E Transponder Control Unit. When a single TDR-94D is installed, the number I transponder must be selected on the CTL-92E. When dual transponder systems arc insta