The balancing and stabilizing of high-frequency amplifiers, with special reference to power amplifiers for radio transmitters

The paper deals with the stabilized high-frequency amplifier, with special reference to power amplifiers for wireless transmission purposes. Part 1 gives a brief sketch of the historical development of the high-frequency amplifier, in which the contributions of Miller and Nichols to the understanding of the nature of the problem, and those of Hazeltine, Rice, and others to its solution, are discussed. Part 2 contains a discussion of the balanced bridge in relation to valve circuits, in which the effects of stray coupling, circuit unbalance, and asymmetry of driving potentials upon the stability of bridge-circuit amplifiers, are considered. Methods of obtaining a neutralizing balance and devices for reducing the effective anode-grid circuit couplings are described. Part 3 gives an account of some experiences met with in the experimental development of a two-stage power amplifier developed by H.M. Signal School, Portsmouth, for naval ship use as a wireless transmitter. Part 4 contains a brief description of the transmitter and some design details.