Please note – finding any detail of the actual specifications of these stations is difficult but an ongoing project – OM
‘ The Equipment Itself
The stations are based upon a 20-foot parabolic reflector, which is fully steerable and which automatically follows the satellite as it drifts through space. The electronic equipment is mounted either on the back of the dish or in three air-portable cabins. The low noise receive amplifier is cooled by liquid nitrogen and the production and handling of this has become an interesting new task for the Electrician Driver of the Troops led by Corporal Colin Pickering and Corporal Mike Reynolds.
For movement by road or by car the station breaks down into seven packages, two which form the antenna mount, three cabins and two 50 KVA generators. These can be mounted on detachable four-wheeled mobilisers. The station takes three hours to dismantle and pack ready for movement, and can be erected and in operation within three hours of arriving on a new unprepared site.’
Copied from – ‘The Wire’ June-July 1969 Page 209 (OM)
Liquid nitrogen for cooling – Norton Barracks circa 1971 before station painted.
The following detail was supplied ‘from memory’ by Lew Lawton –
Operating frequency: 8Ghz
Transmit Output power: 1kw (RFA was a TWT Pre-amp driving a Klystron PA)
Bandwidth: 20 MHz (Using Spread Spectrum Modulation)
Receiver was a (originally) cryogenically cooler parametric amplifier again driven by a klystron but compared to that in the transmitter, a very tiny device.
1 Voice channel
12 Telegraph channels
The data channels used differential encoding to obviate the necessity for a reference carrier. (I remember the vu-foil on the Sky Net course at Oakhanger. – LL)
Code Division Multiple Access (CDMA) permitted all ground stations to use same 20MHz. slot and effectively be hidden below the noise.
Satellite output power was 3 watt.
(Eventually we were able to dispense with the liquid Nitrogen.)
The call signs were GFK1 and GFK2. (I think S Tp had GFK1 and T Tp GFK 2) – LL
Power Supply –
2 x 50KVA Dorman diesel generators – James McMillan