GB449915A - Improvements in or relating to high frequency electrical oscillator arrangements - Google Patents

Abstract

449,915. Discharge apparatus; valve generating circuits. MARCONI'S WIRELESS TELEGRAPH CO., Ltd., Electra House, Victoria Embankment, London.-(Assignees of Linder, E. G. ; 306, Cooper Street, Camden, New Jersey, U.S.A.) Feb. 2, 1935, No. 3463. Convention date, Feb. 28, 1934. [Classes 39 (i) and 40 (v)] In a high - frequency, magnetron, oscillation generator a number of pairs of split anodes 7, 8 are arranged with their centres in a circle, a filament 9 passing in sequence through the cylinder pairs ; the connecting pieces of the filament outside the anodes are either shielded by insulation or made of large diameter to prevent emission. As shown in Fig. 1, the inner halves of the anodes are connected together and through a lead 13 to one side 15 of the antenna, while the outer halves are connected through the tube 11 to the other side 14. The leads 10, 12 from the anode parts to the leads 11, 13 are preferably of a length equal to a whole number of quarter-wave lengths. The anodes potential is obtained from the battery 16 connected through the secondary 17 of the modulating transformer and a choke to a " trombone slide," whose ends are connected to the leads 11, 13. In a modification, Fig. 3, the adjacent halves of the anode pairs are connected, the leads to the antenna being taken out between two adjacent pairs ; the biassing voltage for the anodes is effected through separate chokes 29 connected to nodal points in the connections 24 between the anodes. Instead of a solenoid surrounding the cylindrical surface of the magnetron, an electromagnet may be placed with poles at the ends. The axes of the split anode elements may be at a slight angle to the lines of magnetic force. In a further construction, the anodes 7, 8, Fig. 4, are arranged along the tube, the halves to each side of the centre being separately connected together and to the two sides of the antenna, a choke 29a being included as shown. The current from the battery 16 is applied at a nodal point in the antenna system and the tappings to the anode parts are also taken off at nodal points 33 in the conductors 31, 32. Specification 442,465 is referred to.