allowing it to handle a maximum of 10,000 interrogations per second and making "collisions" unlikely. The practical limit was about 80 aircraft under guidance of two stations at one time. This new scheme was called "GEE-H" (or "G-H") The name "GEE-H" can be confusing, as the scheme was a modification upon Oboe. The name was adopted because the system was based on GEE technologies, operating on the same waveband of 15 to 3.5 metres / 20 to 85 MHz, and initially used the GEE display and calibrator. The "H" suffix came from the system using the twin-range or 'H' principle of measuring the range from transponders at two ground stations. It was nearly as accurate as Oboe itself. In popular culture Oboe appears as a plot point in the "Lost Sheep" episode of the BBC television series Secret Army, which featured the search for a downed airman with technical knowledge of the system. See also List of World War II electronic warfare equipment References Citations Bibliography Attribution External links World War II British electronics Radio navigation Navigational aids Military equipment introduced from 1940 to 1944