GB547061A - Improvements in high-frequency tuning circuits - Google Patents

Abstract

547,061. Coil-less resonators ; thermionic valves. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. May 27, 1940, No. 9293. Convention date, May 27, 1939. [Classes 39 (i) and 40 (iii)] A high-frequency valve arrangement comprises one or more tuning arms extended in a direction perpendicular to the axis of a cylindrical external anode and flanged to embrace the rim of the anode and to give a highly-conductive connection thereto. As shown in plan in Fig. 1, and in elevation in Fig. 3, two valves 1 with external anodes are employed, and the tuning arms comprise parallel plates 5 forming a loop resonant structure lying in tangential contact with the anodes which are sealed to glass envelopes 3 above and below. The plates 5 are formed with a flange 10 which widens out at the part 9 so as to embrace the upper and lower rims of the anodes. The structure is tuned by sliding bars 6 along the inner faces of the plates 5 by means of a right and left-handed screw 7. Rubbing contact is maintained by resilient metal strips secured to one face of the bars 6 and with their ends bent into a plane parallel to the plates 5 and pressed into contact therewith by springs and plungers mounted in slots in the bars 6. Cooling fins may be fitted to the bars 6. Lead-in to the screen grids of the valves is provided by rings 4 sealed into the envelope. The plates 5 are rigidly connected at their outer ends, and supported on insulators 11. The plates 5 may be replaced by pipes or rods.