Method and apparatus for scrambled television

摘要: A method of rendering television transmissions unintelligible to unauthorized receivers in which both video and synchronizing information, typically, is rendered alternately useable unuseable a secret predetermined manner prior transmission. An encoded signal derived from punched card or equivalent digital countdown arrangement added during the blanking time interval signal, then transmitted over air through other facilities. The encoding related to, but enhance secrecy does not directly indicate intervals information. At receiver decoder unit with similar count-down alters information make all useable. ordinary may be used for reproducing as by remodulating onto carrier an unused channel.