GB431599A - Improvements in short-wave valve oscillators - Google Patents

Abstract

431,599. Valve generating circuits. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, BELL, J., GREENTREE, L. J., and MEGAW, E. C. S., c/o General Electric Co., Wembley, Middlesex. April 17, 1934, Nos. 11564 and 16416. [Class 40 (v)] A short-wave valve oscillator comprising a tuned circuit connected at three points 4, 5, 6 to the electrodes of one or more valves has an inductance independent of the tuned circuit connected between grid 1 and cathode 7, said inductance forming with the grid-cathode capacity a circuit resonant at a frequency equal to, or slightly greater than, that of the tuned circuit. As shown in Fig. 1 the inductance is in the form of a pair of Lecher wires 9, 10 connected respectively to the grid and cathode and bridged by a condenser 11 and leak resistance 12. Two valves in push-pull connection may be used, with the Lecher wires connected to the respective grids, Fig. 2, (not shown). In the modification shown in Fig. 3, the inductance is constituted by a plate or plates 7 connected conductively to the grid 2. By virtue of its distributed capacity to anode 1 and cathode 3, and of its distributed inductance, the plate 7 acts as a transmission line equivalent to the Lecher wires 9, 10 of Fig. 1. The tuned circuit 4, 5 of Fig. 3 is connected in series between grid and anode, and a leak resistance 6 connects the grid to the cathode.