Editor’s Note: Ever wonder how much those old transistor radios, valves, multimeters, or telephones you’ve been hanging onto all these years might be worth now? Well, wonder no longer: Steve Johnson ...

There’s still a mystique around vacuum tubes long after they were rendered obsolete by solid state devices, and many continue to experiment with them. They can be bought new, but most of us still come ...

[Mr. Carlson] has an old-style 1940-era radio tube tester, the kind that used to inhabit grocery and drug stores. It is in amazing condition and he was kind enough to tear it down for us. The tester ...

With each passing year, more old radios succumb to “passive” death. The tubes may still be working, but paper capacitors dry out and crack open. Electrolytics gum up and short. Carbon resistors and ...