Development of a New Power Amplifier Tube

A general rule for determining the best operating point and load impedance for any power amplifier when anode voltage and dissipation limits must both be considered is derived. The effect of varying the voltage factor in a given sized tube by changing the grid structure is also considered with voltage and heating kept within safe limits. The process of determining the desired characteristics for a given application is illustrated by describinq the development of a new power tube, Radiotron UX-250.