Vacuum Tubes as Power Oscillators (Part III)

Chapter VI. In the "master oscillator" or "power amplifier" circuit oscillations are generated by a small power source and then amplified. In the amplifier there is no definite phase relationship between plate and grid potentials. The phase is determined by the tuning of input and output circuits. The effect of variations in grid and plate circuit tuning upon output and losses is developed for both direct coupling to the antenna circuit and coupling thru an intermediate circuit. Chapter VII It is shown by the general method of Chapter I that considerable increases in both efficiency and tube output can be obtained by introducing harmonics into the plate voltage wave. The purpose of these harmonics is to flatten the top of the wave so that tube losses may be maintained at a minimum value during a large part of the time during which current is flowing. Appendix-The general explanations of vacuum tube phenomena are supplemented by more detailed data giving the correspondence between theoretical, ideal, and actual values for emission and space charge. The theory of division of primary electrons between grid and plate when both are positive is explained. The effects of secondary emission in producing blocking and influencing efficiency are discussed.