GB403677A - Improvements in telegraphic and similar repeating systems employing vacuum tube amplifiers - Google Patents

Abstract

403,677. Valve circuits. ELECTRICAL RESEARCH PRODUCTS, Inc., 195,Broadway, New York, U.S.A.-(Assignees of Burton, E. T. ; 97, Cypress Street, Millburn, New Jersey, U.S.A.) May 25,1932, No. 14894. Convention date, June 25, 1931. [Classes 40 (iii) and 40 (v).] Specification 315,836, [Class 40 (v), Wireless signalling &c.], relates to an amplifier having a compensating - valve for shaping the characteristic of a main valve. The present Specification describes an amplifier of this kind for use in double-current telegraphy in which the compensator valve 19 conditions the potential drop in a resistance 21 in the plate circuit of the main valves 17, so that while for negative impulses the part ab, Fig. 2, of the characteristic is unaffected, the part bc which deals with positive impulses is transformed to the shape be. The incoming signals are applied through valves and a shaping network to terminals 1, 1 of an input potentiometer 18 which feeds the grids of both the compensator valve 19 and the main valves 17. The outgoing signals are taken at terminals 20 from a resistance 22 and battery 32 which lie in the plate circuit of the main valves 17 but not in that of the compensating-valve 19. The valve 19 is so biassed that it is unaffected by negative signals and has no influence on the part ab of the characteristic of the main valves 17 ; but on receipt of positive signals it produces a potential drop in the resistance 21 and so transforms the part bc of the characteristic to the shape be.