By Joseph Van Loan, Viacom Cable
A proposed Multichannel Sound (MCS) System for televi sian is described, and differences between three proponent systems are discussed. Each of the proponent systems includes provision for transmission of:
- L+R information to maintain compatibility with existing receivers
- L-R information for stereo
- A Second Audio Program (SAP) channel for a second language, quadraphonic sound or as a tutorial channel; and
- A non-public channel for voice and/or data telemetry.
Although immediate wide-scale implementation is not expected, the planned system may have a substantial financial impact on the CATV industry. Headend equipment (including processors, modulators, demodulators and microwave transmitters and receivers) may have to be modified or replaced before passing an MCS signa 1. Present day descramblers will likely suffer deteriorated performance when used on MCS signals, and the MCS signals themselves may suffer degradation when used with descrambling equipment. The introduction of MCS carriers with their increased bandwidth and possible higher levels on a CATV system raise questions about the ability of present day receivers to trap out sound carriers on lower adjacent channels.
The MCS Subcommittee of the NCTA Engineering Committee is conducting tests in cooperation with the Electronics Industries Association and the National Association of Broadcasters to determine the impact MCS signals will have on the CATV industry and to recommend which of the three proponent systems, if any, should be selected.y