A-MAC
In television electronics, A-MAC carries digital information: sound, and data-teletext on an FM subcarrier at 7 MHz. Since the vision bandwidth of a standard MAC signal is 8.4 MHz, the horizontal resolution on A-MAC has to be reduced to make room for the 7 MHz carrier. "A-MAC has not been used in service." Technical details. MAC transmits luminance and chrominance data separately in time rather than separately in frequency (as other analog television formats do, such as composite video). Audio and Scrambling (selective access)