selektor 1976-11

English Electric Valve Company Limited announces the first practical electronically tuned magnetron. Original EEV research, sponsored by CVD, has resulted in the ability to tune mag- netrons electronically 1 00 MHz in X-Band at 50 kW and 30 MHz in S-Band at 200 kW peak power output. This tuning is achieved in a few nanoseconds by the application of a control voltage of 1 to 3 kV to the multipactor cavity electrode. ` The secret of this new EEV patented device is an auxiliary resonant cavity coupled to the main magnetron anode. This is so designed that when an appropriate RF voltage is applied be- tween the electrodes of this auxiliary cavity, a controlled electron multipactor discharge occurs; this causes a resonance shift and so changes the magnetron fre- quency . Several of these auxiliary cavities can be fitted to the same anode to increase the total frequency shift or to give a selection of frequencies , and they add little to its overall size and weight.