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’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 ...

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 ...

Marked: "Sterling R-401 / Vacuum Tube Tester / Serial No. 2563 / The Sterling Mfg. Co. Cleveland, Ohio, U.S.A." Unit is designed to test standard 201-A and 301-A triodes by measuring plate current on ...

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 ...

Marked: "Sterling / R-402 / Vacuum Tube Tester / Serial No. 5764 / The Sterling Mfg. Co., Cleveland, Ohio, U.S.A." Instruction label pasted beneath unit. In original box with instruction sheet. Same ...