Television broadcasting 1960–70: BBC 625-line services and the introduction of colour

Abstract

The paper deals mainly with the development of the BBC 625-line u.h.f. television services and the introduction of colour, but reference is made, where appropriate, to other important developments, both at home and abroad. It also looks at the future and mentions some of the new techniques likely to be exploited to reduce engineering costs, increase reliability, improve performance and extend the range of production facilities. Reference is made to planning methods developed by the BBC, using a digital computer, which have resulted in greater precision over earlier methods. The problems of selecting, testing and acquiring transmitter sites are described, and the conclusion is reached that 98% of the population will be served on u.h.f. by 58 main and 450 relay stations. The paper outlines the equipment arrangements at the transmitting stations and the techniques employed to achieve reliability of service. Reference is also made to the use of a p.c.m. ‘sound-in-synch.’ system of programme distribution to the transmitters, developed by the BBC, which will dispense with separate sound circuits. Following an outline history of experimental colour television in the UK leading to the start of the BBC2 colour service using the Pal system, the paper outlines the problems of choosing colour studio apparatus to meet the production facilities and the impact on studio operations and training. The intercontinental exchange of ‘live’ television programmes in colour has, since 1962, become commonplace through communications satellites, which now cover most of the world. The paper describes how technical problems posed by standards-conversion requirements were overcome and points out that the output picture quality is now mainly determined by the input signal and not by the complexities of the latest standards convertors developed by the BBC. It is considered that there is unlikely to be any change in the basic characteristics of the television picture. In the studio, the increased use of integrated circuits and digital techniques should become economical. Automatic monitoring of programme distribution and transmission networks is expected, among other trends. The paper finally concludes that the 1970s are more likely to be a decade of consolidation, in which we shall see the u.h.f. services extended throughout the UK and the remaining monochrome facilities converted to colour working.