a sure way to get yerself killed or badly shocked is to mess with a tube type radio. unlike transistor radios the tube type have pretty good sized capacitors (those things store electricity, and i mean a bunch of it, and for a pretty long time). in the old days it was no uncommon for the news to report that a person was killed by working on their car radio.
ya know, the advise about the antique radio shopp seems pretty good to me.
be careful, we need all the good bolters we can get!