GB409628A - Improvements in or relating to high frequency signalling systems - Google Patents

Abstract

409,628. Wireless transmitting systems. SOC. FRANCAISE RADIO-ELECTRIQUE, 79, Boulevard Haussmann, Paris. Dec. 13, 1933, No. 35128. Convention date, Dec. 27, 1932. [Class 40 (v).] Relates to amplitude-modulating systems of the kind described in Specifications 270,749, [Class 40 (v)], and 372,090 in which two waves 2, 21 phase-modulated in opposite senses by the signal are combined in an output circuit 5. In Specification 383,928 means are described for de-tuning in opposite senses the output circuits 4, 4<1> of the final stages 3, 3<1> of amplification. The present invention provides for detuning also the input circuits 1, 11 of the final amplifier valves 3, 3<1>, the circuit 1 being de-tuned oppositely to the circuit 4, and the circuit 1<1> oppositely to the circuit 41. The phase-modulating circuits are omitted from the diagram, but their respective outputs are supplied to the valves 3, 3<1> through the coils 2, 2<1>. The grid oscillatory circuits 1, 11 are loaded by resistances 7 connecting the respective grids. In a modification, Fig. 4 (not shown), the aerial or load 5 is connected between the high-voltage ends of two otherwise separate plate circuits 4, 4<1>, whilst the grid circuits 1, 1<1> each include a common resistance element. In a further modification, Fig. 5 (not shown), both elements 5, 7 are arranged similarly to the element 5 of Fig. 3.