Television Station(redirected from Television stations)
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television station[′tel·ə‚vizh·ən ‚stā·shən]
a complex of equipment and facilities used to produce and/or broadcast television programs; one of the basic elements of a television network. Television stations are classified as programming centers or transmitting stations; programming centers usually have their own transmitting stations, forming an integrated television center.
Programs for broadcast originate in a television center—the primary element in the television network. The center’s principal technical facilities are located in the equipment and studio complex. The complex includes television studios with equipment for broadcasting motion pictures, for videotape recording and playback, for integrating transmissions received from other television centers over long-distance communications lines with the program being broadcast, and for transmitting programs to other television centers. The switching of signals in the studio or central control room makes it possible to combine various types of transmissions in any sequence.
A television studio is a soundproof room with up to 1,000 sq m of floor space. The walls and ceiling are covered with sound-absorbing materials in order to create the necessary acoustic environment. A modern studio’s lighting system is equipped with programmed control and can quickly reproduce lighting conditions established during rehearsals. A forced-ventilation and air-conditioning system removes the heat generated by the lighting system.
The program director’s control room is situated next to the studio, both of which are usually on the second floor of the building; it is equipped with operator’s consoles for the program director and sound engineer. The control room is isolated from the studio by soundproof glass, through which the program director can observe what takes place in the studio. The program director uses an intercommunication system to direct his assistants and the television camera operators. At the same time he observes the screens of video monitors to check the images picked up by the television cameras, and he switches in cameras to the transmitter.
The equipment room is located next to the program director’s control room. It contains the basic equipment for amplifying and converting the television signals fed from the studio cameras. The cameras are mounted on dollies and connected to equipment in the control room by multiconductor cable.
The studio and the control room also contain equipment for obtaining the audio signal that accompanies the broadcast video signal.
Broadcasting from a studio makes it possible to establish suitable conditions for televising a program, to make full use of all technical facilities, and to hold as many rehearsals as are necessary. The broadcast picture from the studio cameras is usually supplemented with images taken from various photographs, lettered texts, and graphics previously photographed on film or recorded on videotape. Such techniques are used extensively for news broadcasts and science programs. Television studios also have dressing rooms, makeup and wardrobe rooms, and property and scenery workshops to provide the various services required to prepare actors and sets for a program.
Equipment for broadcasting motion pictures is located in a separate room. The television film projectors for film scanning are optically coupled to television cameras, and movement of the film is synchronized with the motion of the electron beam in the television camera. The equipment for videotape recording and playback is also located in a special room. The number of separate rooms used for motion-picture and videotape equipment and the amount of equipment used depend on the amount of broadcasting handled by a given television center. As a rule, no fewer than three sets of equipment are installed in a center: two are for the continuous showing of films or videotape recordings, and the third is held in reserve. In addition, a modern television center is usually equipped to make its own motion pictures and to process the films. Motion pictures of this type are needed primarily for preparing such programs as news broadcasts. Major television centers also produce feature films, copies of which are exchanged with other television centers. Special film libraries and vaults are used for storing films and tapes.
A television station also includes rooms for editorial and directing staff and for the other specialists concerned with the composition, preparation, and transmission of programs.
Television centers use mobile television units, including portable units, for remote broadcasts from sites outside the studio, such as theaters and stadiums. In remote broadcasting, the cameras are generally at considerable distances from the object being televised and cannot be moved. In order to transmit pictures with different perspective formats, the cameras are equipped with a set of lenses having different focal lengths—from 30–50 mm to 1,000 mm or longer. In order to create the effect of dollying close to a scene while shooting, lenses with variable focal lengths are used. Some mobile television units also have videotape recorders and equipment for transmitting motion pictures. This makes it possible to put together a completely finished broadcast without drawing on the equipment at the studio complex. Mobile videotape recording equipment, mainly in combination with mobile television units, is used to record events to be broadcast during news programs. If frequent remote broadcasts are made from a given site, the necessary television equipment is installed permanently, which shortens the preparation time needed for broadcasts.
The transmitting station is the final link in the television transmission chain. It transmits video and audio signals in the form of radio waves that propagate over the earth’s surface. The transmitting station contains television transmitters, a transmitting antenna connected to the transmitter by feeders and mounted on a support, such as a tower or mast, and control and measuring equipment.
A high antenna mounting makes possible the multipurpose use of the transmitting station. The station usually includes radio broadcast transmitters operating in the very-high-frequency band. If the television transmitting station is combined with a television center, one section of the antenna support is also used to mount receiving antennas for radio links with mobile television units. The antenna support may also have antennas for longdistance radio-relay communications links and sensors for meteorological instruments.
A. M. VARBANSKII