GB625031A - Improvements in velocity-modulated electronic valves - Google Patents

Abstract

625,031. Velocity-modulated tubes. COMPAGNIE GENERALE DE TELEGRAPHIE SANS FIL. May 17, 1946, No. 15037. Convention date, May 16, 1941. [Class 39 (i)] In a velocity-modulation tube of the concentric electrode type, with cathode 15, Fig. 1, negative grid 16 and positive grid 17 between which density modulation takes place, an outer grid 18 of the same potential as grid 17 and forming with it a field-free space, and an anode 19, the field-free space is divided into compartments by a series of radial partitions CD, EF, &c., Fig. 3. The grids 17 and 18 may be formed by the inner and outer edges of the partitions themselves, and these may also be wedge-shaped, so that the compartments are of equal width, Fig. 5 (not shown). The inner openings to the compartments may be partially closed by transverse plates, and the outer openings by a lattice mesh, Fig. 4 (not shown). In a modified arrangement, the inner edges of the partitions engage in V-shaped members 22, Fig. 6, which have a different potential from the partitions, the respective dimensions and potentials being such that the grouping space is still substantially field-free. The invention may also apply to arrangements with central anode and exterior cathode. The Specification as open to inspection under Sect. 91 also describes the basic arrangement of two grids and an anode only, without partitions and third grid. In Fig. 5 (Cancelled), the grids are connected directly via two concentric conducting annuli 2 and 3 in an insulating base-plate 1 to the inner and outer conductors 9 and 10 of a coaxial line, which may alternatively extend inside the envelope, serving to support the grids directly. In a further modification, Fig. 9 (Cancelled), the coaxial lines forming the oscillatory circuit are contained wholly within the envelope, an antenna 14 serving to outcouple the energy. This subject-matter does not appear in the Specification as accepted.