GB444567A - Improvements in or relating to thermionic valves - Google Patents

Abstract

444,567. Thermionic c valves. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Electra House, Victoria Embankment, London.-(Assignees of Rose, G. M. ; 645, Mosswood Avenue, Orange, New Jersey, U.S.A.) June 23, 1934, No. 18624. Convention date, June 24, 1933. [Class 39 (i)] A valve, particularly one of small dimensions for use with very short waves, has an electrode assembly mounted on leads radiating from the assembly and passing between the abutting edges of two parts of a glass envelope, which are sealed together to form an annular seal. As shown in Fig. 1, a cup-shaped indirectlyheated cathode 4 is mounted with a spiral heater 13, embedded in insulating material, in an aperture in an insulating disc 3, mounted on another insulating disc 2. Two circular grids 5, 6 are mounted on insulating or metal frames 11, 12 on the disc 2 and are held by wires 16 .. 19 passing through holes in the discs. The wires .17, 18 are bent under the disc 2 and cut short, and the wires 16, 19 are extended to form leads. The leads to the heater and cathode are arranged similarly to the leads 16, 19. A cup-shaped anode 7 is supported on the envelope 1, which consists of two hemispherical glass parts. Some of the leads are inserted between flared edges of the parts which are then sealed together. In a modification, the cathode and grids are mounted on a single disc with a central aperture. In the triode shown in Fig. 3, the cathode 4 and heater 13 are mounted on a disc 2, the grid 27 is mounted on a thin metal cylinder 25, and the anode 28 is mounted on the disc. The spacing between the electrodes may be 0.005 inch, and the grids may be of very fine wire with 400 mesh per square inch. The valve may be used with a small inductance for generating oscillations of 65 or 30 cms. wavelength.