Believe it or not, every Radio Shack – hell, almost every drugstore – once had a tube tester sitting at the back, available for all to use. Pulling a bunch of tubes out of a malfunctioning radio or TV ...

There was a time when people like us might own a tube tester and even if you didn’t, you probably knew which drug store had a tube testing machine you could use for free. We aren’t sure that’s a ...