When travelling in remote areas and developing countries I like to have a radio with me. There are many reasons for accommodating the extra weight in the rucksack so the biggest decision is usually which radio to take rather than how much it weighs. There are plenty of light weight radios available so most of the thought goes into deciding which features are important and which are unnecessary.
Unless you take a very lightweight crystal radio set that does not require a power supply, you will have to consider how you are going to power the radio. Traditional radio sets use batteries, but there are problems with batteries. They are great whilst they are charged, but what do you do when they run out of charge? Small town stores in developing countries stock items the locals need - and the chances that the locals all need batteries are slim. Consequently, you end up with a great bit of kit that doesn't work. Even if you find batteries the likelihood of them being fresh is slim. The turn over for expensive batteries is slow in places where the average income is a few dollars a day.
Modern technology has come to the travellers' aid through the introduction of mini solar panels and wind up generators that are integral parts of the radio. These innovations enable a radio to run for free anywhere in the world and with absolutely no effort on your behalf when the sun is shining!
With a renewable power supply available, manufacturers have been able to add useful extras to some sets whilst still keeping them small and lightweight. Among the many extra facilities are torches, personal security alarms, and sockets to recharge other appliances such as mobile phones and mp3 players.
By now you will be realising that your radio can be much more than a source of music, news and weather forecasts. It can provide light after dark, keep your phone working, charge your GPS unit, scare off attackers and still not run out of power!
Having solved the power issue, what other considerations are there? Well, the obvious one is 'what can you receive on it?'. Sets that save space and weight by only receiving FM are fine in places like Europe and the USA because the abundance of transmitters means you get a decent signal in most places. In more remote areas FM just doesn't work, the signal gets broken up. The radio needs to receive Medium wave (MW) and Long wave (LW) signals too. International radio broadcasters like the BBC use the long wave frequencies because they can, literally, bounce them right around the world.
Digital radio is even worse than FM for the remote traveller. You wont find a digital signal in a forest, jungle, mountain pass or at sea, and the chance of there being a digital broadcaster in the region is almost non existent anyway. So, LW and MW reception are important features.
Travellers and their kit can have a rough time whilst travelling. My rucksack has been thrown on top of lorries, chucked out of aircraft into heaps of other suitcases, been sat on, trodden on and crushed to death. Kit needs to either be strong or be well protected. Of the two options "strong" is always best.
If a radio looks fragile and a bit tinny in the shop, imagine how it will look after a few days being hurled around in a dusty 35 degree environment! Pick a model with a robust case, low profile knobs and controls and the minimum of holes for dust and insects to invade.
Yes, trivial as it may seem, color is actually quite important. There are tow schools of thought here, boiling down to 'be seen, or not to be seen'. You may have seen radio sets designed for the trekking and wilderness crowd, with a lovely camouflage coloring. Now, I'm not knocking the owners of such sets because I know some are real experts, but ask yourself how easily you will find that radio when you drop it, leave it behind or have it stolen. Will you be able to see if from 50 feet away in a forest? Nope, I doubt it.
So how about buying a bright color one then? You will be able to see it, but so will everyone else. A 20 dollar radio at home is nothing, but that same radio may be worth a month's wages in another country. There are thieves everywhere, at home and abroad, and often the chances of losing something to a thief are related to his or her desire to own what you've got. Would you put an entire month's wages in a bright yellow bag and leave it lying around in the local park? I certainly wouldn't!
Colour then, is a trade off between being able to find the radio and not advertising it too much. I find a splash of bright colour works well. It doesn't give away the shape of the radio, but you know what you are looking for.
To some extent you pay for what you get. However, small radio sets are mainly priced to be competitive with each other so there's not much variation in the main part of the market. If you are feeling rich and particularly like an expensive model, then buy it, but remember what life holds in store for that bit of kit.
I prefer to pay a basic price without making too many compromises on the quality and functions. I never anticipate bringing the radio home with me either. If it survives I give it to somebody who can make good use of it before I come home. If it dies, well actually, there is usually still somebody more than happy to take the remains and do some fixing. Giving away your rechargable radio can provide an income for a local family , and gives you a little more room in your ruckcack for packing presents.
A good radio will be multi-powered, able to receive MW, LW and FM stations, have sockets to supply power to other appliances, be easy to find but not draw attention to itself. It is useful to have a torch built in (that's one fewer item you have to carry with you) and if it makes you feel more secure, look for a personal alarm function. Finally, and most importantly, it needs to be robust enough to survive where ever you travel. All the desirable features are fine, but if it doesn't work, what's the point?