The design of high- and low-power medium-frequency broadcasting transmitters for automatic and semi-attended operation

The paper describes two medium-frequency broadcasting transmitters, rated at 660 watts and 100 kW respectively, and their associated combining circuits. Three of the smaller units are used in parallel to give a 2kW station with fully automatic control, while two 100kW sets make up the semi-attended station at Daventry; however, to conform with international limitations, the B.B.C. operate them at 75kW each, giving 150 kW carrier power from the two units in parallel. Similar transmitters, for both medium-wave and long-wave broadcasting, have been supplied for service outside the United Kingdom.