AN/APS-13 (SCR 718)

AN/APS-13 (SCR 718) airborne "tail warning" radar. "L" band used in fighter planes. Receiver-transmitter, Radar, 410-420 MHz, Pulse, IF 30 MHz, 17 Tubes, Used as a tail warning radar American radar helped deal out the final blows. Both atomic bombs dropped on Japan at the end of the war were triggered to airburst at 580 meters (1,900 feet) by a proximity fuze system, though it was derived from the AN/APS-13 (SCR718) tail-warning radar. The fuze system included four redundant units, known as "Archies", to reduce the possibility of a premature detonation, with the bomb detonating only when two of the Archies agreed that they had dropped through the critical altitude. There was a backup mechanical fuze system in case the electronic system failed, but it worked as advertised. ABA-1 (SCR-515-A) airborne IFF transponder, Mk. IV system. ABK Airborne IFF transponder, series, Mk, II system. AN/APN-1 (Formerly AYF) airborne radar altimeter--L band.