Principles of velocity modulation

Just before the war a number of papers were published on the subject of velocity modulation. Since then very many advances, both theoretical and practical, have taken place, but publication has been impossible. The present paper is a comprehensive treatment of the subject in which improved methods are given for dealing with one group of velocity-modulated devices. The theory presented has been developed by a team of workers in the valve laboratories of Messrs. Standard Telephones and Cables, namely J. H. Fremlin, A. W. Gent, D. P. R. Petrie, C. Strachey, S. G. Tomlin and P. J. Wallis. It is divided into five parts. The first, by Dr. Fremlin, is of an introductory character. Detailed discussion then follows on specific aspects of the problem, as under: Part 2 Small-amplitude theory and starting current, by A. W. Gent. 3 Gap efficiency factors, by D. P. R. Petrie. 4 Power output and efficiency, by P. J. Wallis. 5 Electronic frequency control, by S. G. Tomlin. For the sake of consistency a uniform series of symbols has been adopted, A list of these symbols appears on page 916.