Vacuum-Tube Voltmeter Design

It is shown that for every input range and meter a set of optimum conditions exist, which insure maximum readability, economy, and minimum operating current. Equations are developed (and illustrated with several examples) for the rapid design of a meter for a predetermined range. Optimum conditions are imposed. The dependence of the range secured upon plate circuit impedance is shown and its variation with frequency explained. The procedure for eliminating frequency error up to and including radio frequencies is illustrated.