Is This The Most Common Vacuum Tube On Earth?

In 1940, a British scientist carried a locked metal box across the Atlantic. Inside was a small copper block that a historian later called part of "the most valuable cargo ever brought to our shores." Today, more than a billion of its descendants are in use, most of them inside microwave ovens. The man who turned it into a kitchen appliance got a two dollar bonus. This is the story of the cavity magnetron: the magnetrons that came before it, Randall and Boot's copper block in Birmingham, Magnetron Number 12 and its extra holes, the self-taught engineer at Raytheon who raised production from 17 a day to 2,600, the melted candy bar, the 750 pound Radarange, and the vacuum tube hiding in almost every kitchen. Watch the 12AX7 story, the other vacuum tube that refused to die: https://youtu.be/CtTuwJBRiD0?si=6RYtrSPilxNA2EWs Did you know your microwave has a vacuum tube inside? Tell me in the comments. And if I got a date, a number or a name wrong, tell me there too. I read every comment and I pin corrections. Parts That Changed History tells the stories behind the chips, machines and parts that shaped the modern world, and the people who built them. Subscribe for a new story every day. SOURCES Wikipedia: Cavity magnetron, Tizard Mission, John Randall (physicist), Percy Spencer, Microwave oven, Galanz National Inventors Hall of Fame, Percy L. Spencer Cambridge Historical Society, "Microwaves" (historycambridge.org) Newcomen Society, "80 Years of Cavity Magnetron" #Magnetron #CavityMagnetron #MicrowaveOven #Radar #VacuumTube #PercySpencer #Raytheon #TizardMission #Electronics #ElectronicsHistory #TechHistory #Documentary #PartsThatChangedHistory