It sounds good

It sounds good… reliable reception, CD quality sound, no re-tuning and additional services not currently available from the medium. digital radio will be a must-have audiophile’s dream. Melanie Reynolds tunes in
A revolution is happening on the airwaves and hardly anyone knows about it. But the proponents of it are extremely enthusiastic and there are already products in the shops – if you know where to look that is.
So, what is this revolution? The answer is digital radio of course.
The claims for it are great – reliable reception, CD quality sound, no re-tuning and additional services not currently available from the medium.
While the public might generally be unaware of digital radio at the moment, the manufacturers are certainly not. Several car radio and home hi-fi versions are already on the market and more are coming.
The first products launched were car radios from Blaupunkt, Clarion, Grundig, Kenwood and Pioneer. These have made their way into the specialist shops at prices hovering around the ?700 mark. But they are starting to escape into the main stream markets with high street chain Dixons stocking the Pioneer at two of its major shops.
The BBC is closely tied up with digital radio and has been taking a pioneering role in the technology. Glyn Jones, the BBC digital radio project director keeps his ear close to the ground and hears tell of most digital radio products. The next one expected in the car market is from Sony for around the same price as the competition. “We would expect another two or three manufacturers to come into the market this year or the beginning of next year,” speculated Jones. Digital radio advantages
Digital radio is claimed to be better than FM and AM for the following reasons: Rugged and reliable reception; CD quality sound; No re-tuning while on the move; A wider variety of programmes including text and data services; Easier selection of programmes.
Somewhat to Jones’ surprise the radios are selling at the prices offered, but there is a bigger, as yet untapped, market for cheaper sets now the early adopters are nearing exhaustion. “The dealers are starting to say to the manufacturers we could sell quite a bit more of this stuff when you move the price point,” he explained.
The BBC is keen to see prices reduced. At the point when the choice becomes wider it will feel happier publicising digital radio. “We have to use our judgement quite carefully about who we’re communicating with and at what point,” said Jones. “100 per cent awareness of digital radio at a point when manufacturers are producing first generation sets at high prices and low volume would serve nobody’s interest.”
One manufacturer already working on a cheaper set is UK company Roberts Radio.
It is looking at the portable market and expects its portable digital radio set to retail at around ?200 to the general consumer.
The phase one version, which will be available in spring next year, will have limited availability and its market is expected to be mostly overseas for experimental purposes.
Leslie Burrage, chief executive of Roberts Radio described the initial product as “transportable” rather than portable, mainly due to its greed for power. But with the advances in chip technology the phase two version will be half the size, ending up at around the size of a small mains table radio, and need half the power.
The new technology is also seen as an opportunity to make things easier for the user. “Our products will be designed so they are granny proof,” Burrage eulogised. “Many of the consumer electronic products developed over the years have not been user friendly. DAB is an opportunity to rectify that.”
Burrage sees digital as the future of radio and hopes that Roberts’ early entry into the digital radio arena will help its export potential.
“We will be seeing in the cause of the next ten years significant changes in the manner in which we treat radio broadcasts because with digital the information being transmitted is considerable,” enthused Burrage. “Digital broadcasting is not a flash in the pan. It’s the way broadcasting will develop.” Digital radio in the UK
Broadcasting digitally allows several programmes or services to be combined within one frequency block by using multiplexing. Seven multiplexes have been allocated for digital radio in the frequency range 217.5 to 230MHz (VHF Band III). This allows more than 12 national stereo services and 6 to 12 local stereo services in any given area.
The same frequency is used for digital radio across the whole country which means that unlike now the radio does not need re-tuning when moving from one area to another. There are currently over 230 frequencies being used by broadcasters in the UK and one station can have over ten frequencies across the country – Radio 1 alone uses 22 frequencies.
Digital radio actually makes use of interference from neighbouring transmitters by combining the signals which strengthens the signal at the listener’s radio.
The technology being used is a system called Eureka 147 which has been developed by a world-wide consortium.
It uses COFDM/QPSK, otherwise known as coded orthogonal frequency division multiplex with quadrature phase shift keying. This provides error detection and correction and copes with the interleaving of signals from different transmitters.
The bit rate required to deliver the signal is reduced by using Musicam, which is a compression system in common with MPEG used for video.
Sounds that will not be perceived by the listener are discarded by the system and so not broadcast.


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