GRC-9-Fr Radio Equipment

Like the jeep, the radio transmitter / receiver equipment is an American design built under licence in France.

 The transmitter / Receiver is an RT77 / GRC 9-Fr made by TRT Paris in 1957. It covers 2-22 MHz Am or CW and has an RF output power of 3.5-15 watts.

It can be removed from its mounting and carried in a canvas rucksack (CW 140 GRC9 Fr) for field use. The aerial is in four sections and two sets are carried in a canvas holder (BG 56 Fr).

A padded metal box (BX 53 C Fr) containing a complete set of spare valves (tubes) and lamps for the set made by TRT Paris is also carried in the vehicle along with the headphones, microphone, Morse key and loudspeaker (LS 7 Fr).

The equipment is an American design dating back to the end of WW2 and was made for the French Army under licence. Although the ID plates are in French all controls are labelled in English. Four canvas straps secure the radio to its mounting bracket so it is easy to remove from the vehicle for portable field use where it can be operated from batteries (receive only) or by connecting it to hand operated generator.

The set is powered by a DY88 / GRC 9-Fr converter unit made by MAM Toulouse in 1972 which is mounted over the other rear wheel arch. For field use a GN 58A Fr hand generator set is carried in a canvas holder (BG 173 Fr).

A typical field arrangement of transmitter / receiver, generator, microphone, Morse key, headset and aerial mast is shown in the diagram below.

The GRC-9 was the only set recorded as being fitted in 1961 but from August 1964 the range of sets fitted became: GRC - 9, VRC - 10, VRC - 18, PRC - 10, PRC - 8 & TP - 2A. In November 1969 the range was further extended to include: PRC - 9, PRC - 10, VRC - 9, VRC - 10, VRC - 17, VRC - 18, GRC - 5, GRC - 7, GRC - 9, SCR 506, SCR 508, SCR 528, SCR GD 608, TP VP 13, TP VP 213, TR VP 14, RRTP 2.

During the 1950s the radio and power supply were fitted directly to the rear wheel arches and power was taken, I guess, directly from the battery but in 1960 a power connection box or 'boite de raccordement' was introduced to all new 24 volt jeeps and retro-fitted to older 6 and 12 volt models. In 1961 radio mounting trays were introduced that could be used to fit a wider range of equipment including more than one radio set if required.