Abstract :
A number of possible methods exist for the transmission and reception of the additional sound signal required for stereo on existing television services and some of them are also suitable for the transmission of independent sound signals, such as may be required for a bi-lingual service. The BBC has investigated several of these possibilities and these are described in the paper. The most recent tests are of a two-carrier system, similar to that now used in West Germany, but modified to suit UK System I television. The early trials of this system indicate that there may be difficulty in providing a signal that would be both compatible with existing receivers and able to provide a two-channel service over the existing coverage area.
