What If the Transistor Was Invented in 1921?

The patent cleared in 1924. It changed almost nothing immediately — Eleanor had no capital to manufacture at scale, and the radio industry, flush with vacuum tube patents and the factories to match, had no interest in retooling around a device nobody important had endorsed. For six years, the crystal valve sat in trade journals as a curiosity, occasionally cited, mostly ignored.

What changed it was the Depression. Vacuum tubes were expensive, fragile, power-hungry, and by 1931 radio manufacturers were desperate for anything that cut costs. A small Ohio firm building cheap farm radios licensed Eleanor's patent for almost nothing, mostly because the device needed no heated filament and could run for weeks on batteries that would have died in days powering a tube set.

The farm radio sold better than anyone expected, not because it was advanced, but because it was cheap and did not need electricity a farm often didn't have. Eleanor received a modest royalty check and, more importantly, a letter from an engineer at a growing calculating-machine company in New York, asking whether her crystal valve could be made small enough, and reliable enough, to replace the mechanical relays that made their adding machines so slow and so loud.