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Microwave Oven

December 2, 2003

A public radio commentary

No doubt you have used your microwave oven this week to zap left over turkey, making use of its ability to heat quickly. Yet the oven nearly failed because at first it heated too fast.

The microwave oven is well over fifty years old. It appeared in 1946, a direct descendant of World War Two military technology. A company called Raytheon produced radars for the US armed forces. The heart of a radar is a vacuum tube called a magnetron. This device produces very high frequency radio waves that are absorbed by water and fat, making them rotate rapidly, thus generating heat. The engineers at Raytheon first noticed the heating effect of radar tubes during the cold Boston winters: By accident they learned that they could warm their hands using the output from a radar tube.

Raytheon's first oven in 1946 weighed in at 670 pounds, stood 62 inches tall, and was nearly two feet in depth and width. Not only did it take up floor space, it also required a team to install it: An electrician had to put in a 220 volt line, like those used by washers and dryers today; and a plumber had to install a water line to cool the oven's radar tube. These first ovens sold for over two thousand dollars -- some 17,500 in today's dollars. It was a powerful machine: You could cook a six-pound roast in two minutes and a hamburger in twenty-five seconds.

For the next 20 years, Raytheon tried to sell the oven, but it failed to take off. The real success of the oven occurred in the mid-1960s when Raytheon acquired Amana Corporation, a successful maker of consumer refrigerators. When Amana got a hold of the oven the first thing they did was to slow it down. They redesigned it so it needed less power - and no plumbers or electricians, just plug it into a standard outlet. This slower speed reflected a change in American's eating habits and social structure since the oven's debut in 1946.

The first ovens were intended to cook whole roasts and lobsters. The patent even describes cooking "thick bodies of meat." Yet a microwave oven cooks meat, or large chunks of protein, poorly. By the mid-1960s the faster pace of life, often caused by two working parents, resulted in more packaged food, usually with smaller portions of protein. So, in the new household of the early 1970s the oven thrived as a reheater, rather than as a substitute for a conventional oven.

Amana advertised their new oven across the nation with the slogan "The Greatest Discovery since Fire." By 1978, the microwave oven had spread like fire, rising to fifth place in appliance sales, just behind refrigerators, washers, dishwashers, and air conditioners. By 1985, it had risen to the top becoming the number one best seller.

Copyright 2003 William S. Hammack Enterprises