GB285975A - Improvements in or relating to thermionic valves - Google Patents

Abstract

285,975. Edison Swan Electric Co., Ltd., and Price, T. W. Nov. 23, 1926. Vacuum tubes.-A thermionic valve is provided with a cathode, a main anode, a second anode and a grid disposed between the cathode and both anodes and of coarser mesh adjacent the second anode than at other points. The main anode 2 of the valve V<1> may be connected through a resistance 3 of 5 megohms to the high tension terminal 4 and through a condenser 5 to the grid of a second valve V<2>. The second anode 9 is connected to the terminal 4 through a coil 10 coupled to the tuned aerial circuit 1 connected to the grid 12 and cathode 11 of the valve V<1>. A resistance 7 of 3 megohms and a grid-bias battery 8 are included in the grid circuit of the valve V<2>. The valve V<1> thus gives pure voltage amplification with the main electrodes 2, 12, 11 of high-impedance high amplification factor, and reaction with the anode 9. More than one auxiliary anode may be used to apply reaction to different parts of the circuit. The valve may comprise a helical grid 12, Fig. 4, within a main cylindrical anode 2 and around a single filament 11. One or more auxiliary anodes in the form of small cylindrical segments or of straight or helical wires or tapes 9 which may be interconnected are arranged between the grid 12 and anode 2 and the grid wires are spaced apart farther opposite the wires 9 than elsewhere. In a modification, Fig. 5, the main anode 2 and auxiliary anodes 9 all comprise cylindrical segments around the cylindrical grid 12. In another modification, the main and auxiliary anodes comprise plates on either side of an oval grid surrounding a hairpin filament. The Provisional Specification refers to the use of a two-anode valve simultaneously as a rectifier on the anode bend principle and as an oscillator, regenerator, or amplifier, and describes valves with anodes differently spaced from a flattened helical grid.