London Television Service

Abstract

THE first public demonstrations of the reception of television programmes from the British Broadcasting Corporation's experimental station at Alexandra Palace were given on the occasion of the Radio Exhibition at Olympia in August 1936. These were followed in November by the inauguration of the present television broadcasting service from the same station. In accordance with the recommendations of H.M. Postmaster-General's Television Advisory Committee, the programmes were shared between two separate transmitters installed respectively by the Baird Television Co., Ltd., and by the Marconi-E.M.I. Television Co., Ltd. The object of this arrangement was to enable an adequate, practical test to be made to ascertain the relative ‘merits of the two systems of transmission, which differ considerably in technical details and in scanning speed and picture frequency. According to an announcement in The Times, the Television Advisory Committee has now recommended that the experimental period should be terminated, and that a single set of technical standards should be adopted for public transmissions from the London station. This recommendation has been approved by the Postmaster-General, and provides for a standard of interlaced scanning at a speed of 405 lines per picture, with a picture frequency of 50 per second. The result of this decision is that in future the B.B.C. television programmes from the Alexandra Palace will be emitted by the Marconi-E.M.I. system, although it may be possible to convert the Baird system to the required standards at a later date. The adoption of the new standards, which will not be altered before the end of 1938, will render possible a certain degree of simplification in the design of television receivers. In common with those of other firms, the existing receiving sets made by the Baird Company are capable of receiving the Marconi-E.M.I. transmissions.