APPARATUS FOR COUNTERACTING THE CATHODE CURRENT INCREASE OCCURRING DURING WARMING-UP IN A TRAVELLING-WAVE TUBE IN RESPONSE TO VARIATION IN THE GRID-CATHODE DISTANCE

摘要

Apparatus for compensating the injurious increase of the cathode current occurring during the initial operation period of a travelling-wave tube when, during successive warming-up, the grid first approaches the cathode and then assumes the nominal distance therefrom. The apparatus includes a distance control device measuring the deviation between the actual grid-cathode distance and the nominal distance and generating a control signal proportional to the deviation for reducing the value of the grid voltage.