BC-446 is a 100 watt 200-400 Khz transmitter used for the A-N type of radio range, and also for voice. Weighs 1000 lbs. Has a remote control unit RM-45. TM 11-811, T.O. 31R4-3BC446-11 The military aircraft frequency was 4495. 3105 was for civilian a/c. jhhaynes at earthlink dot net