GoKawiilThe Magic Eye Tube: A Look Back at Radio's Vacuum-Tube Tuning Indicator
The magic eye tube, invented by Allen B. DuMont in 1932, was a vacuum tube used to visually indicate signal strength in radio receivers, helping users tune into stations accurately. RCA released the first commercial version, the 6E5, in 1935, and these tubes remained common in radios until around 1980, when transistors replaced vacuum tube technology.