From time-to-time, this blog feature will present its readers with information related to more-or-less random pieces of equipment. This “series” of blogs generally will focus on Radios, but may on occasion venture into other equipments and apparatus. This blog features the AN/GRC-106A Radio Set.
The AN/GRC-106A was a vehicular mounted radio communications set used in combat areas, from battalion to field army. Originally designed to extend the range of voice communications, this radio was also employed as the basic radio for medium range radio-teletypewriter communications. The AN/GRC-106A was also compatible with manpack equipment used by foot soldiers.
The predecessor to the AN/GRC-l06A was the basic single sideband radio set, AN/GRC-106. The AN/GRC-106 radio was developed to provide combat units with a series of radio sets affording reliable voice, continuous wave and teletypewriter communications. The AN/GRC-l06A featured improved tuning characteristics that allowed for a reduction of the required channel separation from 1 KHz to 100 Hz permitting the 106A to utilize 10 times as many channels as its predecessor.
The AN/GRC-106A was an ultra-rugged single sideband transistorized radio set designed mainly for vehicular mount. The system was composed of two major units 1) Receiver-Transmitter RT-834/GRC, and 2) Radio Frequency Amplifier AM-3349/GRC-106 which were contained in two sealed cases to protect the operating circuitry from dust and moisture. An extreme range of permissible operating temperatures made the AN/GRC-106A suitable for use anywhere in the world.
The AN/GRC-106A was designed such that a standard vehicular generating system provided sufficient power (25 amperes) for voice operation. Teletypewriter operation required a higher capacity generating system (100 amperes). The AN/GRC-106A used a half wave doublet antenna in fixed or semi-fixed positions. On a moving vehicle the AN/GRC-106A used a standard 15-foot whip antenna.
Most of the information to prepare this blog comes from “U.S. Army Fact Sheet Radios No. 4, October 1970, AN/GRC-106A.” This fact sheet and other communications-related documents and photographs are available for review at the CECOM Historical Office. The Historical Office is located at Aberdeen Proving Ground. Contact us via our Web-based contact form at http://cecom.army.mil/historian/contactus.php for additional information.
This post was written by Floyd Hertwck.