Unlike a conventional, analogue signal ? the type used in traditional AM, or FM, radio ? a digital signal is unaffected by weather conditions, hills, buildings, and other sources of interference. This means that DAB digital radio is completely free from hiss, crackle, fading or overlap. Furthermore, a collection of DAB digital radio stations can be broadcast in the air space required for just one FM frequency radio station, so there are many more stations to choose from.

The main, national "multiplexes", or "ensembles" ? as groups, or blocks, of DAB digital radio stations are correctly known ? in the UK, are the BBC network multiplex, and the Digital One network multiplex, both of which are available to 85%, and upwards of the UK population. Digital One is main national commercial radio multiplex, and carries a large number of regional, and local, multiplexes, amounting to several hundred individual radio stations. The actual number of radio stations that you are able to receive varies from location to location, but 40 is a typical number for a major two, or city, and in London the number is over 50. Many of these radio stations are only available on DAB, and many are new, unique stations, catering for specific sections of the population, or niche interests.

If you are familiar with AM, or FM, radio, you may think that tuning a DAB digital radio to one of a multitude of radio stations would be a difficult and frustrating task. This is not so, thankfully, due to the additional capabilities of a DAB digital radio. No tuning, or, indeed, retuning is required; all DAB digital radio stations within range of a receiver are "acquired", automatically.

A list of station names, not frequencies, is displayed, alphabetically, on a screen on the receiver, so it is simply a question of scrolling through the list to find your favourite station. You can also store your favourite stations on a number of preset buttons, so that you can go directly to them. Another attractive feature of DAB is that digital radio stations, from both the BBC, and Digital One, are broadcast on the same frequency across the whole of the country, so if you are driving, there is no need for constant retuning. The Pure Move Digital Radio, for example, is a portable model, which includes a digital preset tuner.

Some DAB digital radios also allow you to effectively pause, and rewind live radio broadcasting. Typically up to 20 minutes, or so, of broadcasting can be held in memory, so your doorbell rings in the middle of your favourite song, or you miss entry details for a competition, you can stop and start, or go back and listen again. The Pure Evoke 3 Digital Radio, for example, includes pause and rewind capabilities.

Pure Digital is a consumer electronics company, based in the UK, which uses technologies developed by its parent company, Image Technologies, in the production of a complete range of critically acclaimed DAB digital radios. Indeed, it was Pure Digital that introduced DAB digital radio to the UK, and the company now dominates the worldwide market.

DAB digital radio is certainly becoming popular in the UK; perhaps it would be better to say "has become" popular, because estimates suggest that, at the start of 2007, almost 10 million people in the UK owned a DAB digital radio. The reasons are plain to see, or hear; interference free reception, a wider choice of digital radio stations ? all of which, unlike digital television stations, are free ? and ease of use, all contribute to making DAB digital radio a real step forward.