GB227138A - Improved means for generating electric oscillations of high frequency - Google Patents

Abstract

227,138. Franklin, C. S. July 11, 1923. Thermionic generators. - In order to enable high power to be obtained in generating oscillations of very high frequency (corresponding to waves of 100 metres or less), a number of oscillation circuits are connected in parallel, and each circuit is connected to the electrodes of one or more valves. As shown in the Figure, three oscillatory circuits are connected in parallel to two bars X, Y, each circuit comprising two coils l<1>, m<1>, a fixed condenser k<1> and a tuning condenser c<1>. The opposite terminals of the tuning condensers are connected to the plates a<1> and grids g<1> of the valves 1, 2, 3, and the filaments f<1> are connected through resistances r' to the ends of the grid coils m<1>. The plate circuits of the valves are supplied through resistances v<1> from a common high-tension bus-bar A, and the filaments from bus-bars F. The coupling bars X, Y keep the oscillations in synchronism, and are connected to each oscillatory circuit through resistances and blocking-condensers, the resistances, which may be in the form of lamps, preventing the setting up of oscillations in the circuits formed by any two valves and the coupling bars. Resistances may also be inserted in the coupling bars, and choke coils in the plate and filament bus-bars. The tuning condensers c<1> are preferably controlled by a single handle. The oscillatory circuits may be coupled to coils o<1>, o<2>, o<3> connected in parallel in the aerial circuit.