The ITA 625-line combined colour/black-and-white service is expected to open on four main stations (101 Crystal Palace, 102 Sutton Coldfield, 103 Winter Hill, 104 Emley Moor), although it is not certain that this will apply to all four stations. The official engineering target date is 15th November 1969. Three further main stations (105 Black Hill, 108 Rowridge, and 113 Dover) are expected to come into service a few weeks later; it is hoped before the end of 1969. Stations with target dates in 1970 and 1971 will come into service as completed.
All ITA UHF transmitters will carry the combined colour/black-and-white transmissions from the time they are taken into service. The 405-line black-and-white-only version of the same programmes will continue to be radiated simultaneously on the existing network of ITA VHF (Band III) stations. Channel numbers refer to the international UHF channels in Bands IV and V.
To achieve national coverage on UHF, comparable with that of the existing VHF network, will require many more main and relay stations than those shown in this first phase; these further stations are being planned to come into operation in the period from 1972 onwards.
Towns and areas indicated on this station list are for guidance only, and detailed coverage maps based on 70 dB above 1 microvolt per metre contours are being published.
In this table, the aerial group refers to the aerial polarization (H is horizontal, V is vertical), and to the recommended RECMF UHF aerial groups:
- A, colour coded red, 21-34 Channels;
- B, yellow, 39-51;
- C, green, 50-66;
- D, blue, 49-68;
- E, brown, 39-68 Channels.
It will be noted that main stations normally employ horizontal polarization and the low power relay stations vertical polarization. However, there are a few exceptions to this general rule; for example, Lancaster relay station with horizontal polarization.
A separate leaflet, ‘Good Viewing of Independent Television’, offers advice on the good reception of ITA colour and black-and-white transmissions.
It should be stressed that most UHF reception problems are due to the use of an inadequate aerial system or its poor location or installation, although it must be recognised that the strength of UH F signals varies a great deal depending not only upon how far away the viewer is from the local transmitter, but also the amount of screening from intervening hills and buildings. The weaker the signal the more important is the need for a really effective aerial, correctly positioned, and aligned accurately upon the transmitter. An important part of the aerial system is the coaxial feeder cable, and for UHF it is recommended that good quality low-loss cable should always be fitted.