Abstract :
A comprehensive theory is developed, combining the relevant parts of present-day circuit requirements with parts of the theories of electronic, mechanical and thermal limitations to valve electrode design, from which data on optimum design emerge. The scope includes amplifier valves with indirectly heated cathodes. Illustrations of theoretical design show general agreement with current practice and indicate directions in which improvement may be sought. Whilst not being a cut-and-dried formulation of valve design, its method may prove a powerful tool in facilitating further development.