What is "d-mac"

Among the family of MAC or Multiplexed Analogue Components systems for television broadcasting, D-MAC is a reduced bandwidth variant designed for transmission down cable.

• The data is duobinary coded with a data burst rate of 20.25Mbit/s so that 0° as well as ±90° phasors are used.
• D-MAC has a bandwidth of 8.4 MHz versus 27 MHz for C-MAC.
• Most cable systems work on EBU 7 MHz channel spacing, so this approach did not work universally.
• D-MAC's bandwidth problems were later fixed by D2-MAC.