GB480074A - Electron discharge apparatus - Google Patents

Abstract

480,074. Thermionic valves. STANDARD TELEPHONES & CABLES, Ltd. June 1, 1937, No. 15220. Convention date, June 30, 1936. [Class 39 (i)] An electron-discharge apparatus comprises a pair of electrode units, each including a cathode, a control electrode and an anode, an electrode of one unit being formed with a portion thereof adjacent -to a portion of an electrode in the other unit to form a condenser therewith, means being provided whereby the capacity of the condenser can be adjusted as desired. The two units may each be mounted in a separate envelope 10 having plane parallel walls 13, and each control electrode 15 is provided with an extension 21 which is adjacent to and parallel with an extension 23 on the anode 22 of the other unit. Metallic or dielectric plates 29 slidable in supports 31 may be adjustably inserted between the walls 13 thus varying the capacity of the condensers formed. In a modification the two units are mounted in a common vessel and a narrow flat envelope is mounted between the grid and anode extensions, liquid, such as mercury or oil, or gas being introduced into this envelope to vary the capacity. The gas may be so chosen as to correct for any change due to temperature in the inter-electrode capacity of the untts. The extensions 23 ... 25 on the anodes serve as cooling ribs. The two units may be used in a push-pull amplifier the condensers formed by the' extensions 21, 23 serving as neutralizing condensers for the inter-electrode capacities of the units.