Magnetically keyed, phase-sensitive demodulators
Robert B. Mark, Wheeler X. Johnson, Paul R. Johannessen · Transactions of the American Institute of Electrical Engineers Part I Communication and Electronics · 1957
THE purpose of this paper is to present several keyed, phase-sensitive demodulator circuits in which saturable reactors, transistors, and silicon diodes are used in place of vacuum, tubes to obtain increased reliability and ruggedness, small physical size (see Fig. 1), and low noise level.