Magic Eye tubes were popular as tuning guides on old-school radio gear. However, the tubes, the 6U5 model in particular, have become rare and remarkably hard to come by of late. When the supply dried ...

A plastic 6-pin base with domed envelope. Donor’s card reads: “Electron-ray tube, glass type, made by the Radio Corporation of America in the early 1930s. An early model of the “magic eye” tuning ...