GB543153A - Ultra high frequency oscillator - Google Patents

Abstract

543,153. Valve generating circuits. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. Aug. 12, 1940, No. 12892. Convention date, Aug. 10, 1939. [Classes 40 (iii) and 40 (v)] A generator comprises a single concentric line resonator associated with a plurality of valves having their anodes earthed and their inputs coupled to.the line. A further concentric line may be coupled to the cathodes for deriving the output energy or a line may be associated with each cathode circuit. Fig. 4 shows a concentric line 1, 2 and coupling loops 3 connected to the valve grid terminal 48 and a further concentric line 2, 13 provided with coupling loops 12 through which pass the filament leads, fine tuning to tune out at least part of the reactance of the filament lead being effected by adjusting screw 28. The anode terminals 47 of the valves 4 are earthed by a strip 18 and the end-plate 19. The line 2, 13 is tuned by a plate 151 arranged at a high impedance point and the line 1, 2, is tuned by the bellows 31, screw 33 and spring 34. The output is taken from loop 14. In a modification, Fig. 7, separate concentric lines 36, 37 are provided for each valve filament tuned by slider 38 and with the output taken from a connection 41 to the line and a balanced output by dividing at a point 42 and arranging that the lines 43, 44 differ in length by one-half wavelength. Fig. 10 shows the mounting of the filament concentric line 36, 37 and the tuning slider S. A centre tapping on each filament is preferably conductively connected to the associated resonant circuit and the ends of each filament capacitatively connected thereto.