TELEVISION SIGNAL DATA ENCODER

TELEVISION SIGNAL DATA ENCODER A head-end facility is provided for encoding selected data into the vertical intervals of one or more received television signals in a manner so as to avoid conflicts with the simultaneous re-broadcasting of the encoded signals. The selected data is generated at the head-end facility in the form of a plurality of pairs of duplicate data packets whose corresponding portions are separated in time by one-half field of a standard television signal. A plurality of channel registers are successively updated by being loaded with one of the duplicate data packets of each pair, the loaded duplicate data packets being non-coincident in time with the vertical intervals of the received television signal intended to be re-broadcast over the respective channel. The contents of the channel registers are successively read and inserted into the vertical intervals of the television signals of the respective channels.