The IOT-a new, environmentally-friendly tube for UHF television transmitters

The inductive output tube (IOT) is a gridded UHF amplifier tube type which has had to wait more than 50 years for the technology to become available to permit the construction of a practical, very high efficiency, UHF-TV amplifier system. The chosen designs of input and output circuits are the key to user-friendliness and efficiency and are discussed in detail. The one major component that the IOT must have and which has delayed the practical realisation of the tube is the grid. The choice of pyrolytic graphite for the material of the IOT grid is explained and the construction method described. The technical, commercial and environmental background which finally led to the appearance of the IOT in the UHF-TV amplifier market-place is outlined.<>