1n22

1N22 is a historical designation used for a germanium semiconductor diode that was commonly employed as a radio detector in early receivers. The designation appeared in the mid-20th century as germanium diodes began to replace vacuum detectors for envelope detection and weak-signal demodulation. Electrical characteristics for units labeled 1N22 varied by manufacturer, but they were generally used for small-signal detection in vintage radio equipment.

Construction and operation attributes of 1N22 diodes are typical of early germanium devices. They were commonly glass-encapsulated with axial leads, though variations in packaging existed. Germanium diodes like the 1N22 offered a lower forward voltage drop than silicon diodes, which aided weak-signal detection, but they tended to exhibit higher leakage currents and greater temperature sensitivity. Performance could differ between batches and manufacturers, reflecting the era’s less standardized semiconductor processes.

Applications and legacy: The 1N22 type played a role in crystal radios, AM detectors, and other early demodulation circuits before silicon diodes and more modern detector technologies became standard. As semiconductor technology advanced, the 1N22 and similar germanium detectors were largely phased out of mainstream production. Today, they are primarily encountered in vintage equipment, restoration projects, and historical discussions of early semiconductor devices, where they are valued for their place in the evolution of radio technology.