GB640833A - Improvements in or relating to thermionic valves - Google Patents

Abstract

640,833. Holders for gas discharge tubes. M-O VALVE CO., Ltd., and BELL, J. May 24, 1948, No. 14018. [Class 38 (i)] [Also in Group XL (a)] The anode 12, Fig. 1, of a thermionic valve is supported by a metal disc 16 passing through the envelope 1, and the seals of the leads to the grid and cathode are on opposite sides of the disc 16. As shown, the grid 9 is supported by a disc 10 to the flange 15 of which connections are made, while the cathode 3 is supported on a tube 2 through which passes the lead 5. A screen 14 prevents deposition on the envelope 1 of material evaporated from the tube 2. Preferably, the external circuits comprise two tunable coaxial lines 19, 20 and 17, 18, Fig. 2 ; the outer cylinder 19 terminates in a flange 28 separated by a mica disc 30 from a flange 29 having projections 36, while the inner line 20 is adapted to fit over flange 15, Fig. 1; the other coaxial line has its inner line 18, Fig. 2, adapted to fit over the end of cylinder 2, Fig. 1, while its outer cylinder terminates in a flange 24 separated by a mica disc 26 from a flange 25 which has projections 32 adapted to co-operate as a bayonet-type joint with projections 36, so that the flange 16, Fig. 1, is gripped between flanges 29, 25, Fig. 2. The anode disc 16 is thus capacitatively coupled to cylinder 17.