A-MAC

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by RJFJR (talk | contribs) at 23:38, 17 April 2016 (change headings). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

The simultaneous PAL transmission of all TV-picture elements and the multiplexed transmission of the TV picture elements with D2-MAC.
Simulated MAC signal. From left to right: digital data, chrominance and luminance

A-MAC carries the digital information: sound, 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)

  • Audio, in a format similar to NICAM was transmitted digitally rather than as an FM subcarrier.
  • The MAC standard included a standard scrambling system, EuroCrypt, a precursor to the standard DVB-CSA encryption system.

TV transmission systems

External links