The KT-76A ATC Transponder is a piece of radar beacon equipment that is designed to fulfill the role of the airborne beacon under the requirements of the Air Traffic Control Radar Beacon System (ATCRBS). The KT-76A is capable of locating the user through the air traffic controller. The KT-76A replies as a set of pulses, selected in number, and positioned in time, one with respect to the other. An identity code number, selected at the front panel by the pilot is transmitted as a Mode A reply. The KT-76A's Mode C, altitude reporting, is a capability designed into the KT-76A that must be used in conjunction with a reporting altimeter and operated in ALT mode in order to convey altitude information to the transponder.

The KT-76A is designed to operate from 13.75 V dc input power. The panel lamps are internally wired to operate from either a 13.75 V dc or 27.5 V dc panel light system, depending on the connections at the rear connector. The KT-76A provides maximum performance at any altitude up to 35,000 feet. The KT-76A measures 1.63 x 6.25 x 10.00 inches and weighs 2.2 pounds.