VISION TRANSMISSION

Nelson Evening Mail, Volume LXX, 3 October 1936, Page 3

VISION TRANSMISSION

EXPERIMENTAL BROADCASTS NEW LONDON STATION LONDON, 30th August. The new London television station has started experimental transmissions. Programmes have been broadcast from the Alexandra Palace and picked up on receivers at the Radio Exhibition at Olympia, where they arc now arousing keen interest among thousands of British and foreign visitors. London newspaper correspondents were this week conducted on a tour of the new station. From a hill 306 feet above sea level the 8.8.C.’s new television station dominates London. It is built into a corner of Alexandra Palace—a North London landmark and pleasure resort for more than sixty years—and from the large bay windows of the upper offices below the aerial nearly all London can be taken in at a glance. The importance of height in this connection can hardly be overemphasised, for under normal conditions the range of the ultra-short waves used for television is extended as the height of the transmitting aerial is increased. Surmounting a tower, itself 80 feet high, is the tapering lattice mast, rising to a height of 220 feet. Thus the aerial array for vision transmissions, which is mounted at the summit of the mast, is more than 600 feet above sea level. Immediately below the vision aerial is the aerial for the accompanying sound transmissions. THREE TRANSMITTERS The new station fulfills the recommendations of the Television Advisory Committee appointed to consider the development of television in Great Britain. Provision has accordingly been made for alternative experimental transmission by the systems developed by the Baird Television Company respectively. Each Company has provided a complete television system, including botn vision and sound pick-up apparatus and the television transmitter itself.

Provision has been made for the comfort of artists in the shape of dressing rooms and a restaurant, for Staff accommodation, for the viewing and editing of films in a miniature cinema, for the storing of properties and scenery, and for many other adjuncts necessary to a smooth-working programme service.

GREY CELLULOSE AND CHROMIUM

The entrance hall is at the base of the tower.. On the left is the entrance to the ground floor corridor, which houses the three transmitters, projection theatre, restaurant, and scenery productions shop. Nearest to the entrance hall is the Marconi —E.M.I. television transmitter .which, like its Baird equavalent, operates on a frequency of 45 megacycles per second (wavelength: 6.67 metres). All the apparatus at .the station is finished in grey cellulose and chromium. Next is the sound transmitter hall which accommodates an ultra-short wave installation of orthodox design for radiating speech and music accompanying the vision signals of both the F-aird and Marconi—E.M.l. systems. Its operating frequency is 41.5 megacycles per second (wavelength. 7.23 metres ).

MINIATURE CINEMA Between the sound transmitter and the Baird plant is the film projection theatre, or miniature cinema, in which the film excerpts can be selected and timed lor inclusion in the transmis* sions. At least thirty people can be comfortably accommodated. The Baird transmitter hall, with its control panel and array of generators and amplification stages, is at the south-west end of the corridor. OUTDOOR TELEVISION An interesting feature is the ramp or sloping runway down which the television camera can travel to a concrete "apron,” approximately 1,700 square feet, on the terrace outside, forming a platform for television open-air performances or special experimental programmes. On the ground floor is the restaurant, providing an all-day ser.vice for the benefit of staff and artists. There is seating accommodation for sixty, and at least 1,000 meals can be provided during a working day. STUDIO DESIGN AND FURNISHING Leaving the tower on this floor wc enter the Marconi—E.M.l. studio. Measuring aporoximateiy iOft by oUtt, with a height of 25ft, this studio is divided into two stages—A and B—of which A, the larger, gives an acting area of approximately 24 square feet. It is equipped with two sets of tableau curtains. Lining the studio on two sides are hanging velvet, curtains running on two tracks, the front curtain being black and the back one white to allow for interchange of backgrounds. Each stage has separate lighting, controlled from a central switchboard. Emitron instantaneous television “cemeras” are used. Across the middle of the studio runs a steel lighting bridge which will allow additional lights to be trained on either stage. The floor is covered with thick black linoleum and the walls are acoustically treated with an asbestos compound. Ne-xt to the control room is the Marconi—E.M.l. tele-cine room containing two projectors and scanning cameras for television films'. Leaving the Marconi—E.M.l. territory,” the Baird tele-cino room comes next It also is fitted with two projectors and the necessary equipment for film transmissions. Next to this room is an additional small studio to be used with the Baird Company s "spot light” system of direct television of three-quarter length portraits such as would be required for announcements and talks. x The main Baird studio is the same size as its Marconi —E.M.I. counterpart. „„„ DRESSING ROOMS On the opposite side of the corridor on the studio floor are the artists’ dressing rooms. Five rooms are for men and five for women, each set of rooms having its own bath. There is also a chorus room. Forty artists can be accommodated 21 wo-

men and 19 men. In each room are buzzer calling signals operated, from the corner of each main studio. There are also an artists’ waiting-room and a special make-up room on the same floor.