The RT-34/APS-13 was a low power UHF tail warning radar transmitter/receiver which was used in Allied aircraft such as the P51 Mustang and also the P-38L, P-47D, P-61, P-63, P-82D in the later stages of the war. The APS-13 operated at 420 MHz with a receiver IF of 30 MHz and was powered by an internal rotary generator which was supplied from the aircraft 27V dc system. The electro-mechanical construction was all aluminium, and the equipment utilized all miniature glass valves except for the voltage stabilizer which was a VR105V (0C3). The PA was two 6J6s. The APS-13 equipment was manufactured by RCA, Camden, New Jersey, USA under a contract number 458-DAY-44 (1944).