Just a follow up/wrap up report.
I got one of these: Go Power! GP-SW300 Power Inverter
It is smaller than I had hoped for and it does have a fan. The good news is that the fan only comes on when the unit gets hot - and I could not get it to come on at all in the hour or so I played around "loading" it up. So its great for running the radio
- in silence.
The thing is also pretty miserly with power. It only consumes .2 amps (12vdc) when "on" and with no load so this unit will be left "on" a lot of the time. It will replace a crappy little portable inverter whose fan ran constantly and and sounded like a cat 5 hurricane
The Go Power is capable of running my cordless tool battery charger
, vacuum and other small things like the soldering iron.
Another plus about this particular size (300w) is that I was able to provide power and circuit protection via the nearby D.C. panel and a 40 amp breaker in an unused spot. This allows me to put some of my paranoia about fire to rest as I am able to remove all
power to the unit when not in use (instead of a larger inverter's requirement to be wired directly to the house bank).
If I ever need more power for larger intermittent loads, I am free to get the noisiest and cheapest (modified sine) around.
I appreciate the help given in this thread. The key piece of info was the part about the fan not coming on when operating at a small percentage of maximum power.