Original URL: http://www.theregister.co.uk/2008/07/21/review_roberts_solardab_radio/

Roberts solarDAB radio

Here comes the sun, little darlin'

By Lewis Caliburn

Posted in Hardware, 21st July 2008 11:29 GMT

Review Undeterred by the unpredictable nature of the great British summer, Roberts has released a radio that it can power itself purely by the light of the sun.

Firstly, let's look at the other functions on the radio, which are pretty good. There's the detachable aerial, for instance. This can be clipped into a recess on the back of the radio to fully protect it. It's a nice feature, but we couldn't help thinking that if the radio was frequently used outside, the aerial could very easily get mislaid. However, once clipped into its little hidey-hole, the aerial is hard to dislodge. So as long as you remember to stow it away, you should be fine.

Roberts solarDAB radio

Roberts' solarDAB: powered by sunlight

Once installed, the aerial is a good size and, although not directional, provides the first link in what is a pretty robust signal-to-output path.

Indeed, the sound quality is better than we'd have expected for a single, small 80mm speaker with just 1W of power to call upon. Clarity of speech for talk radio is good, and any type of music played through the device is delivered in a well-balanced manner. The unit can also maintain clarity at high volume and the volume itself can be turned up quite loud, a useful quality in a product that is destined to spend a lot of its time outside.

A minute of Mozart followed by a snippet of Slipknot revealed that the radio can handle 'subtle' and 'downright brutal' in equal measure. We decided to really give the radio a challenge and tuned it to a birdsong channel - yes, there is one. The broadcast sounds of the woodland birds and beasties going about their business were delivered in a pleasingly natural way.

Moving on, the solarDAB's display is clear enough and of a decent size, although we felt the scrolling information was a little jittery, probably a consequence of the radio being set up to save power wherever possible.

A useful feature - and not often seen on a product at this price point - is the appearance on the display during station searches not only of the current station but also the next one in sequence. The solarDAB can store your ten favourite stations - they are locked in by pressing the preset button, tuning to the station required and then pushing the tuning/select button.

This doesn't sound like a particularly awkward operation, but it does feel a little like that. It would've been easier to just press and hold the preset button when the radio is tuned to the desired station as is the norm with most radios.

Roberts solarDAB radio

The solarDAB is available in five different flavours

There is also the welcome addition of line-in socket for MP3 gadget playback and a headphone port.

In general, the radio’s wedge design provides a good, solid platform, so the unit can cope with uneven surfaces when used outdoors. The rubber sides lock the radio into the palm when you're searching for stations or making other adjustments.

There's no FM tuner and this has to count against the product by limiting where it can be used. However, price points are at play here and the addition of FM may have been sacrificed in concentrating on the unit’s power profile.

Roberts says that the launch of the solarDAB comes just ahead of new EU legislation that will require the UK to start recycling up to 25 per cent of all batteries from 26 September 2008. Currently, the UK recycles a pretty pathetic two per cent of the 30,000 tonnes of portable batteries disposed of each year, the remainder largely ending up in landfill.

The solarDAB does use batteries - handy for when the sun don't shine - but they're rechargeable and kept fed by the radio's top-mounted solar panel.

Does the solarDAB work? Yes it does. There's a little sliding scale that appears on the display when the product is exposed to usable sunlight, with the number of bars displayed representing the amount of power being delivered by the unit’s solar panel. Roberts says if less than half the ten bars are showing, then there's enough power being provided to assist the unit’s rechargeable batteries, and the radio will operate for longer than it would if just relying on the rechargeable batteries alone.

If more than half the bars are illuminated, then the photovoltaic cells can power the radio on its own and have some juice left over to recharge the batteries too. If all the little LED bars are lit, well, you're laughing. The radio can operate without the battery pack at all, but this doesn't produce very satisfactory results.

Roberts solarDAB radio

Is there enough sunlight to power the radio?

We found that the panel was pretty sensitive. We placed it behind a heavily frosted window on a moderately sunny day and there was still around half the bars showing. Indeed, a nice sunny windowsill is the radio's preferred spot. But it is outside that it really comes into its own.

Even moderate sunlight means the radio can keep going for really long periods of time, even at a decent volume. On its own, without assistance from the panel, the radio can manage around a quoted and basically accurate 27 hours of playback. If the weather is really good, it can keep going as long as the sun shines, in theory at least.

Verdict

One of the Register Hardware team took the radio to a recent festival and reported that the handy device provided enough chill-out sounds for a full three days and still had power on his return. If you listen to the radio to any great extent outside then this is a really useful little addition to any holiday, camping trip or day on the river bank.