Television Comes to the Centre of England 

17 December 2016 tbs.pm/9924

From the Radio Times published 9 December 1949

On Saturday, December 17, television takes a giant stride forward when the BBC begins broadcasting from Sutton Coldfield — the world’s most powerful television transmitter. Here, Sir Noel Ashbridge tells you something about the transmitter and, what is very important, its expected service area; he also outlines the BBC’s plans for bringing television to eighty per cent of the country’s population by 1954

SERVICE AREA OF SUTTON COLDFIELD. This map shows the distance of principal towns within eighty miles of the Sutton Coldfield transmitter. Sir Noel Ashbridge, in his article, devotes considerable attention to the question of the transmitter's service area. It should be understood that towns shown on this map outside the fifty-mile range are not necessarily in the service area.

SERVICE AREA OF SUTTON COLDFIELD. This map shows the distance of principal towns within eighty miles of the Sutton Coldfield transmitter. Sir Noel Ashbridge, in his article, devotes considerable attention to the question of the transmitter’s service area. It should be understood that towns shown on this map outside the fifty-mile range are not necessarily in the service area.

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This is a close-up view of the top of the 750 ft. aerial mast at Sutton Coldfield. The television aerial is seen at the very top; the cylindrical structure below is concerned with BBC intentions to broadcast on very high frequencies.

On December 17 a new transmitting station for television will be formally opened by the Postmaster-General. It is situated at Sutton Coldfield about ten miles north of Birmingham and by now the mast will have become a well-known landmark. It is also a landmark in another sense, because it is the first step in a very large scheme to develop television on a nation-wide basis. The function which this particular station has to perform is to give a television programme to the large densely-populated area usually somewhat vaguely referred to as ‘the Midlands.’ It has frequently been referred to as a relay station because it will normally send out the same programme as the London station at the Alexandra Palace, but in this country the term ‘relay station’ rather suggests a low-power ‘satellite.’ This is perhaps somewhat misleading because the new station is considerably more powerful than its forerunner and is so far the most powerful of its kind in operation anywhere in the world.

Its opening marks the first step in the BBC’s scheme of making television programmes available to as large a proportion of the whole population of the United Kingdom as technical conditions permit. When the existing plan is complete some eighty per cent or more of the population will be catered for on the basis of a good service and no doubt there will be many who do not come within this category who will nevertheless think it worth while to provide themselves with a television set. Moreover, it should bring some seventy per cent of the population into the service by the end of 1952 and the remaining ten per cent before the end of 1954.

This is a definite target and in normal times one which could be attained with no special difficulties except those which are inevitable in the pioneering of a new service. In present circumstances, however, it must be subject to any further revision of the amount of permitted capital investment which the Government may consider necessary as a result of the economic crisis.

In planning stations of this type which must of necessity work on wavelengths much shorter than are used for ordinary sound broadcasting — in fact as low as 5 or 6 metres — it is especially important to choose a site as high as possible above sea level. Moreover, in addition the location of the site must be very carefully chosen to cover the large areas of dense population especially aimed at. This involves the carrying out of elaborate tests using a barrage balloon to raise a temporary aerial to the same height as the mast which will eventually carry the permanent one. As a result of such tests a particular piece of land at Sutton Coldfield was chosen which is about 550ft. above sea level. The mast is 750ft. high so that the aerial itself is some 1,300ft. above sea level, which incidentally makes it necessary to take special precautions against icing. The aerial weighs a few hundred pounds only, but the mast, which has to carry it, weighs some 140 tons.

The vision transmitter is the most powerful which could be built for such a wavelength, at any rate without further lengthy experimental work. It is rated at 35kW while the separate sound transmitter has a power of 12kW. These figures can be compared with 17kW and 3kW respectively for the Alexandra Palace transmitters, where the height of the aerial is only some 600ft. above sea level.

As a result of the preliminary tests with the balloon aerial a normal range of fifty miles was estimated, but this of course is very definitely an average and there must be wide variations in the strength of reception following the contours of the land between the receiver and the station. It is a characteristic of the very short wavelengths used for television that they are more affected by hills, trees, and tall buildings than the wavelengths used for ordinary sound broadcasting; there will in fact be shadows or patches of weaker reception behind steep hills and high buildings, the extent of which is almost impossible to predict accurately. Thus while the average range should be about fifty miles it will for example be greater to the east than to the west where the Welsh hills will constitute a formidable obstacle.

The control desk for the sound and vision transmitters

The control desk for the sound and vision transmitters

Preliminary tests have recently been carried out from the station working on full power which would seem to show that greater ranges than those estimated will be achieved. Time will show how far reception from these much greater distances is satisfactory and reliable as a regular service. In the end it will probably be found that while reception at a hundred miles is at any rate feasible in some directions it certainly is not in others. However this may be, ‘Sutton Coldfield’ is likely to cover a considerably greater area than the London station.

rt19491209-coverIt has been mentioned already that programmes will normally come from London and will of course be the same as those radiated from the Alexandra Palace. This naturally involves transmitting the programme from London to Sutton Coldfield — without in any way impairing its quality — a difficult engineering operation which is carried out by the General Post Office Engineering Department. At first a chain of small highly directional wireless stations, working on very short wavelengths, specially erected for the purpose, will be used. At a later stage a new special cable, which has been laid between London and Birmingham, will become available as an alternative to the radio link which was originally constructed for experimental purposes. The cable can carry programmes in either direction so that it will be possible for an outside broadcast in Birmingham to be radiated from the Alexandra Palace as well as from Sutton Coldfield, and of course eventually from all the other stations in the chain.

There is much work to be done involving considerable expenditure before this chain is complete, but there is only one factor liable to stand in the way of its completion in reasonable time and that is the national economic position. It is the first nation-wide scheme of its kind in the world to be put into even partial operation and so far as the BBC is concerned it has the highest priority.

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