Astra Digital Radio - 1

Radio stations so far have been using analogue frequency modulation (FM) to broadcast via subcarriers of TV programmes bearned down by the Astra satellites. A new system, calied ADR (Astra Digital Radio) has seen rapid acceptance both with the receiver industry and large TV broadcasters. The all-digital system enables twice as many sound programmes to be transmitted than the old analogue system. Instead of two subcarriers for a stereo programme, ADR only requires one for all the relevant sound information, plus additional services. This allows a single Astra transponder to carry one TV programme and no fewer than 12 ADR channels. DMX (Digital Music Express) is the first pay radio station to make use of ADR.