MIL-H-55535A, MILITARY SPECIFICATION: HEADSET-MICROPHONE KIT MK-1039/G (23-JAN-1967) [S/S BY MIL-DTL-55535A]

MIL-H-55535A, MILITARY SPECIFICATION: HEADSET-MICROPHONE KIT MK-1039/G (23-JAN-1967) [S/S BY MIL-DTL-55535A]., This specification covers Headset-Microphone Kit MK-1039/G. This Headset-Microphone Kit is designed to fit both the regular and large size Combat Vehicle Crewman\'s Helmet. The electrical characteristics of the kit are compatible with Tactical Radio Systems, such as the VRC-12. The impedance of the microphone circuit is 150 ohms, and the earphone elements are transformer matched and present a 500-ohm load to the earphone circuit. The equipment covered in this specification is intended for use in audio accessories for the Combat Vehicle Crewman’s Helmet.