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28.10.17

GRC-109

this radio introduced as a spy set.
It was “The Jeep of the radio world” as dubbed by a former Special Forces radio operator in Vietnam



They were used extensively from the early 1950’s (as the RS-1) through the 1970’s and beyond by the CIA, Special Forces, other US military and allied units worldwide.









transmitter output of between 10 – 15 watts, a built in key that works well, versatile power supply options and a sensitive receiver, they did the job.  The transmitter covered the frequency range of 3 to 22 MC in 4 bands; the receiver covered 3 to 24 MC in 4 bands.


 History of the GRC-109 [See the similar historical information under the RS-1 section.]
The GRC-109 started production about 1961. Compared to the RS-1, GRC-109 units have more date-coded components, and more documentation is available to support those dates. GRC-109A units have a 1969 contract date on the ID plate.
In late 1961, the CIA organized a number of 12-man Special Forces teams to work with Montagnard tribesmen, and used the RS-1 for communications. Meanwhile, the Army's chief signal officer arranged for the RS-1 to be adopted for military use and renamed the GRC-109. Even though the Army had many RS-1 sets in use already, giving it an Army identifier would have simplified logistics. By late 1962, the Special Forces team network had 24 stations. The GRC-109 set in each "A detachment" SF camp was kept in a sandbagged bunker, with several antennas installed. The antennas were a target of Viet Cong raids, but for emergencies, they found that a longwire buried 18" underground in bamboo pipes could be used. [Ref. 6]
The GRC-109 became a standard issue radio to all combat units in forward areas after 1965. It was included in the inventory of all fire bases, and was at least used as a backup radio. Even though Special Forces had access to the latest high-tech radios, by the mid-1970's many units had adopted the GRC-109 as their primary long-range radio. It was rugged, reliable, and maintainable in the field, and offered several power supply options. The newer radios tended to require specialized batteries which were often not available in the field.
Estimated dates are summarized as follows:
·         RS-1: 1950-1964 (RT-3 #6487, a late-production unit, has apparently-original tubes dated early 1964).
·         GRC-109: 1961-1969 (PP-2685 #88 has parts dated 1961).
·         GRC-109A: 1969-1973 (units have a 1969 contract date).
GRC-109 notes from John Liner:
[Regarding reliability:] I never had a 109 fail to function. I was always able to communicate and send my traffic through with it. I operated in many different locations, including an A camp in Viet Nam, the forests in southern Germany, and out of apartment buildings in downtown West Berlin.
[Regarding the apartment building use:] I used the big power supply that is part of the GRC-109 kit [PP-2684]. The antenna was a broomstick with about 50-75 feet of wire wound on it, with another 10 feet trailing off the end. The coil of wire sort of made the antenna look electrically longer. I placed the broomstick in a window and let the wire dangle out of it. Other guys have used stairwell banisters for antennas. For a ground I just ran a wire to the radiator in the room (most old German pre-war apartments had steam heat).
GRC-109 notes from Don Valentine:
We had small dry batteries for the AN/GRC-109 receiver so we wouldn't have to crank that %$#@%$# generator to send and receive messages. I never saw a PA-109 while I was in SF. Apparently, it was only for transmitting and the operator had to have a dry cell battery for the receiver or have the team gorilla crank that &%$@#$ generator.
The 109 was very forgiving if you didn't erect a by-the-book antenna. When in Laos, I communicated from Luang Prabang to Vietiane using a coat hanger. It would even load a military vehicle, wire clothes line, or barbwire fence and use that for an antenna.
The AN/PRC-74 replaced the GRC-109 on the SFODs in the mid-60s, except for the A Camps in Vietnam. We helped test the proto-types while we were assigned to Project Delta [Det. B-52, 5th SFGA] in Vietnam. The proto-types were called HC-162s




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