GB430199A - Improvements in or relating to high frequency oscillation generators - Google Patents

Abstract

430,199. Thermionic valves. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Electra House, Victoria Embankment, London. (Assignees of Thompson, B. J. ; 139, North Arlington Avenue, East Orange, New Jersey, U.S.A.) April 30, 1934, No. 13016. Convention date, April 29, 1933. [Classes 39 (i) and 40 (v)] A high frequency oscillation generator of the Barkhausen-Kurz type has a filament cathode with spaced sections lying in a plane, a grid electrode parallel with the cathode and maintained at a high positive potential, a plate - shaped retarding electrode on the far side of the grid from the cathode, and a fourth electrode so placed and at such a potential, preferably negative, that a uniform field is maintained at the surface of the cathode. As shown in Fig. 1, the cathode consists of two V-shaped sections 19, on one side of which a grid electrode 18 and a retarding electrode in the form of a dished plate 17, are mounted, and on the other side a fourth electrode consisting of a plate 2, 3 with bent edges 24 overlapping the edges of the retarding electrode, is mounted. The spacing between the grid and the cathode should be equal to or less than the average distance between the sides of a cathode loop and equal to or less than the spacing between the grid and the retarding electrode. Dimensions and voltages are given. The electrode 23 may be curved or crinkled to provide surfaces extending between the parts of the loops. In another arrangement, Fig. 4, the grid 27 and retarding electrodes 26 are of box shape, the cathode consists of two straight filaments 28 joined together at both ends by connectors 29, and the fourth electrode consists of three strips 34 arranged in the plane of the cathode. A Lecher system, consisting of two wires adjustably bridged by a blocking condenser, may be connected between the grid and retarding electrodes, chokes being inserted between the wires and the supply. A modulating circuit may be connected between the fourth electrode and the cathode. The Specification, as open to inspection under Sect. 91, comprises also a valve generator in which the positive electrode is a perforated or grid-like plate mounted between two M-shaped filament cathodes, which are surrounded by a box-shaped electrode maintained at a negative potential. The grid and box-shaped electrodes are connected with the Lecher system. This subject-matter does not appear in the Specification as accepted.