Improvements in and relating to thermionic valves for use in wireless telegraphy andtelephony

摘要

250,847. Preston, L. G., Shearing, G., and Irving, G. A. Jan. 24, 1922. Vacuum tubes.-External metal surfaces are provided on a thermionic valve which form, with internal surfaces, capacities in parallel with seals so as to ensure the safety of the seals when the valve is carrying large High-frequency currents. As shown, an external cylinder K is mounted adjacent to the anode A, and a. similar cylinder D is mounted adjacent to an internal cylinder C' connected with the grid C. The condenser formed by the cylinder K and anode has a greater capacity than that between the anode and grid. The cylinders D, D are connected to the seal conductors G, H respectively, at points X, Y chosen 'so that the reactance of the circuits formed by the condensers K, A and D, C1 are much less than the inductive reactances of the circuits XG, YH respectively, and, for this purpose, additional reactances may be included in the circuits XG, YH. The high-frequency currents are thus carried by the condensers KA, DC', and the unidirectional pulses by the seals.