The story of who invented the microwave, like so many stories of twentieth century innovation, begins with a weapons manufacturer. In the 1940s, Raytheon, the mammoth defense contractor, was investigating the use of certain vacuum tubes for use with radar detecting sets for the U.S. military. One of the company's engineers, Percy Spencer, discovered a curious property of the tubes, known as magnetrons. They melted a candy bar in his pocket.
Intrigued, Spencer did what any self-respecting scientist would do, and started running experiments. He quickly confirmed that microwave energy could cook food, working first with popcorn and then with an egg. Raytheon quickly filed a patent, it was worth a shot, and developed the first microwave oven. By 1945, the Radarange would be on the market. It was a microwave that bears little resemblance to our tidy units of today. It ran on 3 kilowatts of electricity and was so inefficient that it required a water cooling system.
Raytheon was far more experienced at marketing fighter jets than kitchen appliances , so it licensed the technology to the Tappan Stove Company. Unfortunately, Tappan couldn't manufacture the new ovens at a price point that would penetrate the home appliance market. People weren't willing to spend thousands of dollars on a curious new technology that would cook food with radioactive energy.
Raytheon was undeterred, and decided to try to crack the market itself. The company bought Amana, revived the Radarange moniker and had a low priced model on the market by 1968. The radioactive seeds were planted for the microwave revolution.
During the early period of microwave market penetration, the only companies that made the units were defense contractors. After all, they were the ones who had all the magnetrons. However, as the sales of microwaves skyrocketed-they surpassed sales of gas ranges by 1975-other appliance manufacturers started to get in on the action. Today, as many as 90 percent of American households claim a microwave as a member.
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