"Our thinking ... as far back as April of 1948 was that if video information could be handled in the same manner as high quality sound recording by the use of magnetic tape, mechanical techniques would be simplified and optical steps would be eliminated. The operation of VTR is based on a method which is introduced primarily to conserve tape velocity and thereby to provide at least a quarter of an hour running from reels of reasonable size. Instead of recording a single track down the length of the tape as is done in sound work, thereby necessitating high velocity for the band of frequencies involved, we employ ten tracks simultaneously for the video information ... an eleventh track is employed for the vertical and horizontal synchronizing signals and a twelfth track carries the sound channel. On playback, the signals from the ten video tracks are combined to produce a high definition picture. Recording and replay were via a 10-tap delay line, sound being FM coded on a 100(K)Hz carrier with 50 to 150 Hz deviation."