E.M.I. cathode-ray television transmission tubes

This paper gives a short history of the development of two types of cathode-ray tube now used for transmission of television pictures. The construction and mechanism of operation of the ¿ Emitron¿ is described and its limitations are discussed. A further development, namely the ¿Super-Emitron¿, is then described, and its mechanism of operation and its performance are compared with those of the ¿Emitron¿. Some other types of transmitting tubes, which have been tested experimentally in the course of this work, are described briefly.