I have an aircraft radio and I don't know if it works. Is there any place I can take it to have it checked?

Well, probably your best bet is to find an avionics shop and have them bench test it. Of course they're going to charge you for this, but that should dramatically increase what you can get for it. If you look at it from a buyer's perspective, buying a radio as-is without knowing if it works is a crap-shoot. If you have a serviceable tag from a shop that's just a few days or weeks old, your buyers are going to have at least some assurance that the radio is good--or at least it was when it was tested. I'd look in your local phone book for aircraft maintenance facilities. Not all do avionics work, but they can at least point you in the right direction as to where you can find someone that can. Alternately, you could maybe find an aircraft owner who has the same make and model of radio and swap yours out in his or her airplane to see if it works. The problem with that is what if your radio has some sort of short or other problem that fries the aircraft owner's avionics stack--they're not going to be too pleased. A shop with a test bench can isolate these things very quickly, and you won't have an angry airplane owner who's going to want you to pay to fix his or her airplane because of your radio.

www.easternavionics.com mail it to them and then prepare to bend over. Any radio shop will rape you but they will be polite about it.