Programmes originate from various sources all over the country. In our Master Control they are linked, together with the commercials, to make a continuous days viewing for the Midlands audience. Most commercials are made on film and are shown by means of a special television camera and projector combination called a Telecine machine.

Tonight you will see a programme from our Studio A. The scenes are looked at by four television cameras and the sound is picked up by a number of different types of microphones, some on fixed stands, some mobile on devices called booms and some carried by the individual artistes. After the cameras have turned the pictures into electrical impulses, the engineers adjust and process these ‘electrical pictures’ to conform to the high standard of television which is required.

In the studio control room the producer selects the pictures he wishes to transmit, and a girl operates a control panel according to his requirements. Part of the vision mixer which this panel controls was designed by the Engineers at Alpha and a large range of effects can be carried out. One picture can be changed into another by means of wipes, dissolves or cuts. On special occasions arrangements can be made to provide the foreground of a picture from one camera and the background from another. Therefore, with a camera on the roof, an artist standing in the studio might appear to be on the chimney tops of Aston.

The ‘electrical sounds’ are processed, balanced and checked for quality, and sent with the picture to Master Control. Continuous programme leaves Master Control and is carefully checked for quality before it is sent on its route to the transmitter.

In this country the General Post Office handles most of the television network distribution system between cities and it is through the Post Office cables and radio links that our picture and sound reach the local I.T.A. Transmitter.

Throughout the Independent Television network the technical quality is being constantly checked by highly skilled engineers. In order to enable the engineers to locate a fault quickly a system of private telephone lines, almost as complicated as the television distribution system itself, links the engineers of the I.T.A., the G.P.O. and the various programme contractors. A fault noticed in Birmingham may well start as far away as Scotland and has to be put right within a few seconds of being noticed.

The engineers at Alpha are constantly searching for improved methods of operation of equipment to produce still better picture and sound quality in your homes, and persistantly strive to maintain the finest possible television service to you the viewers.

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Picture Shape

Does everyone look tall and thin? Or short and fat? Adjustment of the ‘Height’ and ‘Width’ controls can usually correct this sort of trouble. This is most easily carried out just before the start of the day’s programmes when the test card is transmitted, the aim being to get the circle as round as possible while still retaining the chequered border.

Note: ‘Height’ is sometimes called Vertical Amplitude or Vert. Amp., and ‘Width’ is often Horizontal Amplitude or Hor. Amp.

If the circle persists in being egg-shaped it will be necessary to adjust the linearity (or form) controls, as well as the height and width.

Picture Contrast

The aim here should be to obtain pictures in which all the tones from black (shadow details, folds in clothing, etc.,) to white (shirts, highlights in the hair) are well reproduced. The harsh ‘soot and whitewash’ pictures one often sees can lose just as much detail as the thin, grey, grainy variety. Try to keep in your mind’s eye the last good film you saw, or that photograph which impressed you so much. It should be possible to get that sort of quality by careful adjustment of the brightness and contrast controls, the former for the dark tones and the latter for the face tones and highlights.

The clarity of the picture can also be improved by the setting of the focus control (it is surprising how many blurred pictures one sees!)

SOUND QUALITY

Your receiver is capable of a high standard of sound reproduction. The fine tuning control associated with the station or channel selector should be set for best sound consistent with the sort of pictures discussed above. A wrong setting can produce effects on the screen such as wobbling or vibration, and at the other extreme a loud, harsh buzz in the loudspeaker. Select a compromise setting.

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• Population within measured contours: Primary 5.01 mn, Secondary 1.51 mn, Fringe 0.93 mn. Total 7.45 mn.
• Channel: Band III Channel 8 (vertically polarised)
• Vision Carrier Frequency: Actual 189.75 Mc/s
• Sound Carrier Frequency: Actual 186.25 Mc/s
• Effective Radiated Power: Vision 400 kw maximum. Sound 100 kw maximum.
• Power of Transmitters: Vision (peak white) 20 kW. Sound (carrier) 5 kW
• Heights above sea level: Site 500 ft. Mean aerial 1,450 ft.
• Location: 1° 45′ 40″ W, 52° 36′ 30″ N.

Lichfield (Channel 8)

Companies: Associated TeleVision (weekdays), A.B.C. Television (weekends)

Geographically, the siting of a station to serve the industrial Midlands proved fairly straightforward, because the service area of the BBC’s Band I station at Sutton Coldfield corresponded closely with that which the Authority also wished to achieve. High open ground in the area is scarce and, with reason, carefully protected. It was not therefore easy to find an acceptable site. A piece of land 500 ft. above sea level, about four miles north-east of the BBC station, was eventually secured. It lies near the Watling Street in the rural district of Lichfield, from which the station derives its name.

Initially, an available design of 450 ft. self-supporting steel tower was erected, carrying an omnidirectional aerial similar to the one used at Croydon but of twice the aperture. This enabled a service to be provided quickly. The station went into programme service on 17th February 1956 with a single 5 kW transmitter, giving an effective radiated power of 6o kW. A few months later the power was raised to 120 kW by paralleling two 5 kW sets into the split aerial. In November of the same year, after the main 20 kW transmitter had been installed, the power was raised to 200 kW e.r.p. This gave a population coverage of nearly 6.5 million within the o.25 mV/m contouur. From the start it was recognised that, because of the relatively low site, greater and more uniform coverage could be obtained with a higher mast and an aerial system with directional characteristics. Sufficient land was therefore acquired to permit this to be done later.

Early in 1961 it became possible to start the construction of a 1,000 ft. mast and an improved aerial. Both these were brought into service in July of the same year, thus allowing the original tower to be dismantled and re-erected for use at the Fremont Point station in the Channel Islands. The new aerial enabled the power radiated south towards Gloucester to be increased to 400 kW.

Towards East Anglia, however, the power had to be reduced to 100 kW to prevent harmful interference to viewers of the Netherlands Television Service on the Dutch coast. For this reason, the service to Midlands viewers living east of the station remained substantially unchanged. Over a semi-circle towards the north the radiated power was maintained at 200 kW. This was sufficient, with the higher aerial, to close the gaps between the service areas of Lichfield and the Winter Hill and Emley Moor stations. The effect of the new mast and aerial was a general all-round improvement in reception, both within the old service area and beyond. The predicted coverage is shown in the map opposite. The measured coverage has recently been completed and includes a population of 8.85 million within the 0.25 mV/m contour.

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