GB478970A - Improvements in and relating to electron multipliers - Google Patents

Abstract

478,970. Electron multipliers ; circuits. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. July 27, 1936, No. 20759. Convention date, July 26, 1935. Drawings to Specification. [Classes 39 (i) and 40 (v)] A multiplier comprises a cathode, one or more multiplying electrodes, and an output electrode, and means are provided for setting up an electrostatic field withdrawing electrons from the cathode and multiplying electrodes and a magnetic field directing electrons on to the multiplying electrodes and for applying to this or to an auxiliary magnetic field electrical variations to modify the output of the multiplier. A multiplier of the kind described in Specification 469,477, may be employed, and modulating potentials may be applied across the magnetic field coil or in series with the current supply to this coil. Carrier frequency oscillations may simultaneously bo applied to an input grid, or across a resistance in the leads to one or more multiplying electrodes, or may be generated by the tube itself, for example by coupling the output to the input grid or multiplying electrode circuit. In another generator, the main or an auxiliary field coil may be coupled to the output, and modulation may be applied to the grid or to a multiplying electrode. Modulated carrier oscillations may be applied to the grid, and local oscillations may be generated in the multiplier or applied to the field coil, demodulation being obtained by utilizing the curved portion of one of the multiplying electrode voltage-output current characteristics. Amplification is then obtained by succeeding stages. A photo-electric cathode, upon which falls light varying at carrier frequency may be used. Oscillations may be generated by inserting a tuned circuit in the lead to a multiplying electrode.