Introduction to duobinary encoding and decoding

With a dozen or so MAC TV signals available from satellites such as TV-SAT2, TDF-1, Olympus, Astra and, shortly, BSB, it is surprising to note that relatively few electronics engineers and satellite-TV reception enthusiasts appear to be aware of essential technical backgrounds to MAC. In line with the theme of the month, communications, this article looks at one aspect of the MAC transmission standard that has received little attention so far: duobinary encoding and decoding of the sound and data block.