Harmonic Production and Cross Modulation in Thermionic Valves with Resistive Loads

The harmonic and modulation components in the anode current of a thermionic valve (tube), operating with a resistive load, are obtained in terms of coefficients of the power series by which the load characteristic is expressed, and amplitudes of the voltages applied to the control grid. An example is given in which it is shown that the presence of a large signal on the grid of an output pentode greatly increases the distortion of a small signal of different frequency.