The Gee system used three phase locked pulse transmitters that were located in the south of England. The R1355 receiver (bottom right) picked up these pulses that were then displayed on the Indicator unit type 96(bottom left). Gee worked on the principle of measuring the difference in arrival time of pulses from two transmitters located in the U.K. By measuring this time difference and relating it to similarly marked lines on a map you could identify which line you were on. Repeating this a second time using another pair of pulses and a second set of lines on the map, your position could be determined. One master station, the 'A' station, was common to both sets of pulses such that three transmitters were only required rather than four. The indicator unit had an extremely accurate time measuring system that could result in distance measuring resolutions of better than 1 mile.

The third unit (top right) is built to resemble a type 5 control unit. An original one would have controlled the high frequency alternator used to provide power to the system. The simulated control unit now contains a static inverter for providing the high frequency power needed, together with a circuit that simulates the transmissions that would have occurred during the war, thus an active demonstration can be given to members of the public.

The final image is the Gee Indicatort installed in the navigators section

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