RF components for high power and super power UHF-TV transmitting systems

The super power and tall tower has required the development and use of `all waveguide´ RF components rather than the conventional coax RF components. As the power on the coax line increases, the diameter must also increase to keep the temperature rise on the inner conductor to within safe limits. For any frequency there is an upper limit on the diameter; above which moding will occur and prevent the practical use of coax line. When this occurs, waveguide must be used as the RF transmission line. MCI has been the principal high power waveguide development laboratory for this type of activity, for the past 20 years. The author presents the criteria for converting from coax to waveguide. Data is also presented on several dual channel high power waveguide installation. Performance data of some of these new waveguide components is also presented. Block diagrams of some typical 120 kW and 440 kW systems are shown and discussed