GB642702A - Improvements in and relating to electric discharge devices - Google Patents

Abstract

642,702. Thermionic valves. BRITISH THOMSON-HOUSTON CO., Ltd. Nov. 27, 1944, No. 23659. Convention date, Nov. 26, 1943. [Class 39 (i)] An electron discharge device adapted for insertion between adjacent sections of a concentric transmission line comprises two cylindrical electrodes 11, 12 of equal dimensions having shoulder portions 18, 23, and cylindrical extensions 19, 24 extending towards one another and a grid or control electrode 13 supported between the electrodes by a metallic plate 27 The cathode extension 19 has an electronemitting face 16 with heater 22 within and filter arrangement 30 from one of the heater conductors to the wall of the electrode. An aperture 31 connects the spaces for evacuation. Two insulating cylinders 28, 29 sealed between the electrode shoulders and the metal plate 27 form the sealed region of the discharge device while the remaining parts of the electrodes together with conducting extensions 42, 43 attached by spring-like fingers 44 form the inner conductors of concentric lines, the outer conductors being cylinders 35, 36, tuning plungers 46, 47 being positionable within these cylinders. Cylinders 35, 36 have transverse ring members 37, 38 attached to their ends which are secured together by bolts 39 and at their inner edges have spring-like fingers 40 which engage the metal grid support 27. The anode is provided with cooling means consisting of an inner apertured cylinder 60 which directs a stream of air against the active surface 25 of the anode and the walls. A feed-back coupling loop 57 may extend between the anode-grid or grid cathode cavities.