The Technology of Television Program Production and Recording

The basic concepts for television origination equipment are determined by operational requirements, which have remained relatively constant throughout the history of television broadcasting. In brief, television cameras and related studio equipment are designed to permit the assembly of a smooth flow of picture and audio signals from multiple sources, including both "live" scenes and prerecorded material. The photography of kinescope images on motion-picture film was an early approach to practical television recording which still offers enough advantages that major engineering efforts continue to be placed on the development of improved film recording equipment. A great deal of the current television recording activity, however, involves the use of magnetic tape. The most common types of television tape recorders employ 2-in. wide magnetic tape, on which picture information is recorded by rotating video heads which produce tracks extending across the width of the tape. Four separate heads are mounted on the rotating headwheel, but switching circuits are employed to deliver a single continuous signal during the playback process. Through the use of FM techniques and precise servomechanisms, it is possible to accomplish television tape recording with extremely high picture quality.