GB234025A - Improvements in and relating to electrical valve amplifiers - Google Patents

Abstract

234,025. Priess, W. H. Nov. 14, 1923. Thermionic amplifiers and detectors.-Transformers or choke coils of the type described in Specifications 233,737 and 234,023 are applied to multi-valve circuits comprising radio-frequency feed-back links, or ordinary reflex arrangements. Fig. 1 represents three stages numbered 1 - - 3 of high-frequency amplification coupled by ironcored transformers wound from high-resistance wire, followed by a detector valve D<1>. The output from No. 3 valve is fed back to the grid of No. 1 by a link comprising a fixed or variable condenser K<9> and inductance I<9>. Any known phase-adjusting means may be included in the feed-back link. A similar back-coupling link may be inserted between the grid and plate of the same valve. which mav also function as a detector. In Fig. 3 the rectified output from the detector valve D<1> is fed back to the grid of valve No. 2 for further amplification through an audio-frequency transformer X of the type previously referred to. In Fig. 5 the low-frequency output from a crystal detector D is reflexed on to the grid of valve No. 2 through transformer X, the amplified low-frequency currents from that valve being transferred to valve No. 4 through a similar type of transformer Y.