Vestigial-sideband transmission at u.h.f.

625-line u.h.f. television transmissions in Europe and the United Kingdom use a vestigial-sideband channel allocation. The use of a vestigial-sideband system enables more channels to be accommodated in the u.h.f. bands, but it can result in the transmission in a given channel interfering with that in the lower adjacent channel. In the paper, the specification of the radiated spectrum of 625-line u.h.f. transmissions is considered. Descriptions are given of experiments and calculations that make it possible to specify the radiated spectrum of u.h.f. transmitters in such a way that interference with the lower adjacent channel is avoided, while at the same time the radiated signal suffers an acceptably low measure of distortion.