GB619700A - Improvements in or relating to electric discharge devices - Google Patents

Abstract

619,700. Velocity-modulated tubes. WESTERN ELECTRIC CO., Inc. Oct. 29, 1946, No. 32107. Convention date, May, 19, 1945. [Class 39 (i)] The electron stream from the cathode 2 of a discharge device is velocity modulated by a resonant cavity 19. The envelope contains an ionisable atmosphere, i.e. helium, the varying degree of ionisation consequent upon the velocity modulation of the beam being utilized to provide an output signal. In Fig. 5, the negative electrode 42 collects the positive ions produced, and the positive electrode 67 the electrons which have a reduced velocity due to ionising collisions, while the electrons with unreduced velocity are collected by electrode 68. These electrodes are connected respectively to their source of potential 5 through the primaries of a three-section transformer whose secondaries 62, 64, 66 are so connected in series that the cumulative effect of the induced currents is utilized across resistor 53 for an output signal. Electrodes 67 and 68 may be integral, and the collection of electrons and ions may be utilized directly in a pushpull circuit without using a transformer (Fig. 4, not shown). The positive ions alone may be used to obtain the output signal (Fig. 3, not shown), and the electron path may be straight (Fig. 1, not shown), instead of curved, and the divergence of the electron beam reduced by a surrounding magnetic coil. A further modification, Fig. 2, has annular collecting electrodes 30-35, with a final collector 36. In still further modifications, the output signal is derived from the varying collection of electrons alone. Fig. 6 (not shown) and Fig. 7 (not shown), have retarding electrodes for collecting electrons slowed up by ionising collisions, the remaining electrons being utilised for the signal. In Fig. 8 (not shown), and Fig. 9 these remaining electrons are passed through a second resonant cavity 81 from which the output signal is taken by coaxial line 84. U.S.A. Specification 2,288,256 is referred to.