Some notes on grid circuit and diode rectification

The equivalent input resistance of a grid leak and condenser in parallel and the combination in series with a diode or the grid-cathode circuit of a triode are calculated for various combinations by means of the static Ig-Eg, characteristics and an extension of the work of Colebrook and Peterson and Llewellyn. The equivalent internal resistance of the diode is also calculated and an expression for the equivalent generator is also derived. The relations between X, the grid condenser modulation frequency reactance, R, the grid leak, and m, the percentage modulation, to give good quality are considered theoretically and experimentally. The part played by the values of X, R, and m in the quality of the audio-frequency output was first considered by Terman and Morgan. Limiting values of X and R for the cases of the triode and diode are also estimated.