The operation of superheterodyne first-detector valves

The equivalent anode circuit of a superheterodyne first-detector valve is derived, and the fundamental circuit constants (conversion conductance and effective anode a.c. resistance) are defined. Mathematical analysis leads to a method of measuring effective anode a.c. resistance and five methods of measuring conversion conductance, all of which are described in some detail. Graphs are included to illustrate these methods and show the degree of agreement between them.