Restoring the Freshman Masterpiece AM radio was a lot of fun, but using batteries wasn’t. They’re convenient for testing, but expensive for regular use. The “B” battery alone uses ten 9-volt batteries, and that’s over $20 per set. There are battery simulators available for old tube radios, but they’re not cheap either, and where’s the fun in just buying a plug-in power supply? Wouldn’t it be cooler to use solar power and a 12-volt rechargeable battery?