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 ...

There is nothing simple about a good vacuum tube tester. In fact, most tube testers were very complicated to set up for each different type of tube to be tested. Testing a quantity of different tubes ...