For serious listening check out the Nasa HF3w. It tunes 30Khz to 30Mhz so yo can receive all long, medium and short wave stations.(Both AM a SSb though not vhf fm ) As a bonus, if you connect it to a pc, you can also get radiotelex, navtex and weatherfax.
Don't let the 12V become an issue - if you've got a 6V or a 9V radio, it's easy enough to drop the voltage for something which pulls so little current.
I've used secondhand car radios on my last three boats - never had a problem(yet!). The only problem with the modern car radios is that they need a seperate power feed for the 'memory' which I don't like. It just means I have to programme the stations every time I go on board - no real problem - it usually stays on R4.
Yes a car radio but it is worth trying to find an old manually tuned, with a knob and dial, radio. Car radios are inherently quite sensitive and cheap.
olewill
[/ QUOTE ]How are you charging it when it goes flat? I was thinking of using one of these, I have one on the shelf behind me ready (2.4Ah) and adding one of those little trickle solar panels to keep it topped up. Do you just bring yours home to charge every so often or have you found a simple way to keep it charged.
Now I have it connected to the main battery as I have wind/solar charging and between them on my boat the radio doesn't even make a dent on the power supply on board. I ask as many people will have the same problem and I am interested in your solution.
The keep alive voltage requirement for the usual digitally tuned radio is fairly small. A decent sized electrical system will cope with the load assumnig you don't leave it on for months on end without running the engine.
My tiny electrical system 1W solar will not cope with a car radio requirement.
Re the separate battery you could fit a diode from the main power supply to the +ve of the SLA battery. This will give it some charge when the engine is running. ie 14v less the diode loss of .7 volt gives 13.3 which is perhaps useful but safe for the SLA battery. olewill