Single channel split-sound receiver for use with television set

Claim 1

A split-sound receiver for reproducing foreign language audio signals accompanying a television signal received on a particular channel of a television receiver, said television receiver radiating a radio frequency signal when the television receiver is tuned to television channel, said television signal including a first sub-carrier modulated in accordance with audio signals representative of a first language and a second sub-carrier modulated in accordance with audio signals representative of a second language, said receiver comprising: an antenna for receiving the radio frequency signal from the television receiver when the television receiver is tuned to a particular television channel; band-pass circuit means coupled to said antenna and tuned to said particular television channel to pass only the radio frequency signal associated with said particular television channel; first detector means coupled to the band-pass circuit means for converting the radio frequency signal passed by said band-pass circuit means into an intermediate frequency signal of a selected intermediate frequency; circuit means coupled to said first detector means and including a sub-carrier detector circuit responsive to said intermediate frequency signal from said first detector means for detecting said second sub-carrier to recover the second language audio signals; a speaker; and output circuit means connecting the output of said sub-carrier detector circuit to said speaker to apply said second language audio signals thereto.