Microwave Oven
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Greetings,  The Southwest Museum of Engineering, Communication and Computation is seeking :

 artifacts, books, papers, personal recollections, funny stories, newspaper clipping, magazines, catalogs, articles torn out of magazines,  cartoons, prototype magnetrons,  really early microwave ovens etc  ANYTHING Is Fair Game!

The purpose is two-fold which consists of construction the display in the museum in Glendale Arizona  and also as an addition to our web site.

thanks Ed Sharpe archivist for SMECC

Please check our web site at
to see other engineering fields, communications and computation stuff we
buy, and by all means  when in Arizona drop in and see us.


 coury house / smecc
5802 w palmaire ave
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thanks Ed Sharpe archivist for SMECC

The microwave oven was invented as an accidental by-product of war-time (World War 2) radar research using magnetrons (vacuum tubes that produce microwave radiation, a type of electromagnetic radiation that has a wavelength between 1 mm and 30 cm).

In 1946, the engineer Dr. Percy LeBaron Spencer, who worked for the Raytheon Corporation, was working on magnetrons. One day at work, he had a candy bar in his pocket, and found that it had melted. He realized that the microwaves he was working with had caused it to melt. After experimenting, he realized that microwaves would cook foods quickly - even faster than conventional ovens that cook with heat.

The Raytheon Corporation produced the first commercial microwave oven in 1954; it was called the 1161 Radarange. It was large, expensive, and had a power of 1600 watts. The first domestic microwave oven was produced in 1967 by Amana (a division of Raytheon).

In 1967, Amana, a division of Raytheon, introduced its domestic Radarange microwave oven, marking the beginning of the use of microwave ovens in home kitchens. Although sales were slow during the first few years, partially due to the oven’s relatively expensive price tag, the concept of quick microwave cooking had arrived. In succeeding years, Litton and a number of other companies joined the countertop microwave oven market. By the end of 1971, the price of countertop units began to decrease and their capabilities were expanded.

Spencer, born in Howland, Maine, was orphaned at a young age. Although he never graduated from grammar school, he became Senior Vice President and a member of the Board of Directors at Raytheon, receiving 150 patents during his career. Because of his accomplishments, Spencer was awarded the Distinguished Service Medal by the U.S. Navy and has a building named after him at Raytheon.

Percy Spencer, while working for the Raytheon Company, discovered a more efficient way to manufacture magnetrons. In 1941, magnetrons were being produced at a rate of 17 per day. Spencer set out to create a simpler magnetron that could be mass produced. The result was a magnetron that replaced precision copper bars with lamina and replaced soldered internal wires with a simple solid ring. These improvements and others allowed for the faster production of 2,600 magnetrons per day.

In 1945, Spencer created a device to cook food using microwave radiation. Raytheon saw the possibilities of this, and after acquiring Amana Refrigeration in 1965, was able to sell microwave ovens on a large scale. The first microwave oven was called the Radarange, and today, there are over 200 million in use throughout the world.

A Brief History of the Microwave Oven

Like many of today's great inventions, the microwave oven was a by-product of another technology. It was during a radar-related research project around 1946 that Dr. Percy Spencer, a self-taught engineer with the Raytheon Corporation, noticed something very unusual. He was testing a new vacuum tube called a magnetron (we are searching for a picture of an actual 1946 magnetron), when he discovered that the candy bar in his pocket had melted. This intrigued Dr. Spencer, so he tried another experiment. This time he placed some popcorn kernels near the tube and, perhaps standing a little farther away, he watched with an inventive sparkle in his eye as the popcorn sputtered, cracked and popped all over his lab.

The next morning, Scientist Spencer decided Microwave Oven Inventor Percy Spencerto put the magnetron tube near an egg. Spencer was joined by a curious colleague, and they both watched as the egg began to tremor and quake. The rapid temperature rise within the egg was causing tremendous internal pressure. Evidently the curious colleague moved in for a closer look just as the egg exploded and splattered hot yoke all over his amazed face. The face of Spencer lit up with a logical scientific conclusion: the melted candy bar, the popcorn, and now the exploding egg, were all attributable to exposure to low-density microwave energy. Thus, if an egg can be cooked that quickly, why not other foods? Experimentation began...Actual Microwave Oven Patent by Percy Spencer

Dr. Spencer fashioned a metal box with an opening into which he fed microwave power. The energy entering the box was unable to escape, thereby creating a higher density electromagnetic field. When food was placed in the box and microwave energy fed in, the temperature of the food rose very rapidly. Dr. Spencer had invented what was to revolutionize cooking, and form the basis of a multimillion dollar industry, the microwave oven.
(Click HERE to learn even more about Dr. Percy Spencer)

Nearly 6 Feet Tall, Weighing 750 Pounds

Engineers went to work on Spencer's hot new idea, developing and refining it for practical use. By late 1946, the Raytheon Company had filed a patent proposing that microwaves be used to cook food. An oven that heated food using microwave energy was then placed in a Boston restaurant for testing. At last, in 1947, the first commercial microwave oven hit the market. TOne of the earliest microwave ovenshese primitive units where gigantic and enormously expensive, standing 5 1/2 feet tall, weighing over 750 pounds, and costing about $5000 each. The magnetron tube had to be water-cooled, so plumbing installations were also required.

Initial Reactions Were Unfavorable

Not surprisingly, many were highly reluctant about these first units, and so they found only limited acceptance. Initial sales were disappointing...but not for long. Further improvements and refinements soon produced a more reliable and lightweight oven that was not only less expensive, but, with the development of a new air-cooled magnetron, there was no longer any need for a plumber.

The microwave oven had reached a new level of acceptance, particularly with regard to certain industrial applications. By having a microwave oven available, restaurants and vending companies could now keep products refrigerator-fresh up to the point of service, then heat to order. The result? Fresher food, less waste, and money saved.

New and Unusual Applications

As the food industry began to recognize the potential and versatility of the microwave oven, its usefulness was put to new tests. Industries began using microwaves to dry potato chips and roast coffee beans and peanuts. Meats could be defrosted, precooked and tempered. Even the shucking of oysters was made easier by microwaves. Other industries found the diverse applications of microwave heating quite advantageous. In time, microwaves were being used to dry cork, ceramics, paper, leather, tobacco, textiles, pencils, flowers, wet books and match heads. The microwave oven had become a necessity in the commercial market and the possibilities seemed endless.

The First "Radarange"

In 1947, Raytheon demonstrated the world's first microwave oven and called it a "Radarange," the winning name in an employee contest. Housed in refrigerator-sized cabinets, the first microwave ovens cost between $2,000 and $3,000. Sometime between 1952-55, Tappan introduced the first home model priced at $1295. In 1965 Raytheon acquired Amana Refrigeration. Two years later, the first countertop, domestic oven was introduced. It was a 100-volt microwave oven, which cost just under $500 and was smaller, safer and more reliable than previous models.

By 1975 Sales of Microwave Ovens Exceeded that of Gas Ranges

 Technological advances and further developments led to a microwave oven that was polished and priced for the consumer kitchen. However, there were many myths and fears surrounding these mysterious new electronic "radar ranges." By the seventies, more and more people were finding the benefits of microwave cooking to outweigh the possible risks, and none of them were dying of radiation poisoning, going blind, sterile, or becoming impotent (at least not from using microwave ovens). As fears faded, a swelling wave of acceptance began filtering into the kitchens of America and other countries. Myths were melting away, and doubt was turning into demand.

By 1975, sales of microwave ovens would, for the first time, exceed that of gas ranges. The following year, a reported 17% of all homes in Japan were doing their cooking by microwaves, compared with 4% of the homes in the United States the same year. Before long, though, microwave ovens were adorning the kitchens in over nine million homes, or about 14%, of all the homes in the United States. In 1976, the microwave oven became a more commonly owned kitchen appliance than the dishwasher, reaching nearly 60%, or about 52 million U.S. households. America's cooking habits were being drastically changed by the time and energy-saving convenience of the microwave oven. Once considered a luxury, the microwave oven had developed into a practical necessity for a fast-paced world.

An expanding market has produced a style to suit every taste; a size, shape, and color to fit any kitchen, and a price to please almost every pocketbook. Options and features, such as the addition of convection heat, probe and sensor cooking, meet the needs of virtually every cooking, heating or drying application. Today, the magic of microwave cooking has radiated around the globe, becoming an international phenomenon.

Inventor Spencer

Doctor Spencer continued at Raytheon as a senior consultant until he died at the age of 76. At the time of his death, Dr. Spencer held 150 patents and was considered one of the world's leading experts in the field of microwave energy, despite his lack of a high school education.

On September 18, 1999, Dr. Percy LaBaron Spencer was inducted into the National Inventors Hall of Fame and took his place in history alongside such great inventors as Thomas Edison, the Wright Brothers and George Washington Carver.

More to come on the fascinating history and development of the microwave oven...

Note: Photo of Percy Spencer and Patent provided courtesy of The Spencer Family Archives
Picture of the earliest microwave oven provided courtesy of The Lemelson-MIT Awards Program's Invention Dimension web site, http://web.mit.edu/invent

 Picture of Original Microwave Oven Patent by Doctor Percy L. Spencer
Courtesy Rod Spencer and the Spencer Family Archives
Actual original patent for the microwave oven by Dr. Percy L. Spencer

Copyright Information

Unless otherwise noted, all materials at this cite (including without limitation all text, html markup, graphics, and graphic elements) are copyrighted ©, 1989-2001 by J. Carlton Gallawa. The material available through this site may be freely used for attributed noncommercial educational purposes only. We ask that due credit and notification be given the author.


Amana Radarange

Amana Refrigeration, a subsidiary of Raytheon Manufacturing Company, in 1967 introduced this first compact microwave oven, called the Radarange. It was a 115 V countertop model, retailing for $495, and cooked hamburgers in 35 seconds. The compact size was made possible by a small, efficient electron tube, developed in 1964 by the Japanese, which replaced older, bulkier tubes called magnetrons.

In 1968, tests by Walter Reed Hospital confirmed many fears that microwaves did, in fact, leak out of the ovens, but Federal standards set in 1971 resolved the problem. By 1994, ninety per cent of all US homes had such an appliance.

The first microwave ovens for home consumer use were introduced by Tappan in 1955, but few purchased them due to their large size (about like an electric stove) and high cost.

Microwave ovens were a spin-off of wartime RADAR, and invented accidentally by Percy LeBaron Spencer of Raytheon while working on a magnetron (radar tube) near the end of the war. As he passed the device, which generated microwaves, he noticed that a candy bar in his pocket began to melt. He experimented with eggs (they exploded) and popcorn (it popped). So, a "high frequency dielectric heating apparatus" was patented in 1945 by Raytheon, and a prototype built. The first microwave oven for commercial purposes (ships and hotels) was introduced in 1947 by Raytheon, and named the Radar Range. It stood five and a half feet tall, weighed 750 pounds, and cost $3000

30th Anniversary of Microwave Oven Marks Revolution in America’s Home Kitchens

Return to News Index

AMANA, Iowa — It’s been 30 years since the first household microwave oven was introduced to families across America. Hailed as a technological breakthrough and criticized as a gimmick that would ruin the fine art of cooking, the Amana Radarange was debuted in Chicago in 1967 as a product that would forever change how Americans eat and cook.

The microwave oven has come a long way since then. Today, more than 90 percent of America’s households include a microwave oven. And, in a recent Yankelovich Partners study, Americans ranked the microwave oven as the No. 1 technology that makes their lives easier, right ahead of the telephone answering machine and the automatic teller machine (ATM). According to Dixie Trout, Amana vice president of consumer communications, many Amana engineers envisioned the microwave oven replacing the conventional oven.

Microwave oven
Introduced in 1967, the Amana Radarange microwave oven would forever change the
way American families prepare meals.

“It was a time of astronauts, instant Tang orange drink and TV dinners,” says Trout. “And many appliance manufacturers, such as Amana, aimed to take the drudgery out of the typical homemaker’s life and replace it with the modern conveniences of the ‘home of the future.’ In reality, it was the dawn of the ‘Supermom,’ which was spurred by the large number of mothers who entered the workforce.”

“In retrospect,” Trout adds, “while the microwave oven did not replace the conventional oven entirely, we now have an entire generation that’s grown up with the microwave oven, and have come to rely upon it just as much as their PCs and cell phones.”

The first Amana Radarange microwave oven was powered by a 115-volt current, says Trout, and it featured just two buttons, “start” and “light.” It also included two control knobs, one for cooking times up to five minutes, and the other for longer cooking times up to 25 minutes.

Demonstrating just how far microwaves have evolved, today’s Amana microwave oven line features a unit with 1,000 watts of cooking power and electronic controls with pre-programmed pads. According to Trout, it cooks food in half the time, costs 50 percent less, and features a contemporary, streamlined design compared to the bulky, sterile look of the original model.

To say the Amana Radarange oven changed the landscape of American cooking and eating is an understatement. “It sparked a revolution,” says Marcia Copeland, director of General Mill’s Betty Crocker Kitchens. “Not only did it allow us to cook food quickly, it also offered us the opportunity to make food we might not have because of our busy lifestyles — especially in the area of snacks, such as microwave popcorn.”

“The microwave also paved the way for new food products that children could prepare safely,” Copeland adds. “Parents feel comfortable letting kids prepare after-school snacks or starting dinner with the microwave.”

“The microwave oven is the No. 1-rated technology in our Monitor research for making people’s lives better,” says J. Walker Smith, managing partner, Yankelovich Partners. “It’s moved from giving people instant gratification to making life easier, which fits perfectly into the lives people are trying to lead today.”

Smith notes, “Our research shows that nowadays people of all ages are trying to strike a balance between work and personal activities. The home has become a sanctuary from life’s stresses. And the microwave oven is important to this because it makes it possible for family members to spend less time in the kitchen and more time in the family room.”

The microwave oven also has dramatically modified kitchen design, adds Ann Steiner, who writes a nationally syndicated column on microwave cooking with CiCi Williamson. “When it was first introduced, the microwave oven was considered a gimmick. Today, it’s as essential as the kitchen sink. It’s no longer resting on the counter — many people purposely plan their kitchen remodeling projects around the microwave oven.”

Beyond the confines of the home kitchen, the microwave oven’s impact has been felt in a number of other ways. For example, the fast food and food service industry heavily rely on microwave ovens to meet the demands for quality food served fast.

“At Amana, we pride ourselves on developing high quality, innovative products,” says Trout, “but no one here in 1967 could have imagined the enormous impact the Radarange has had on American society. Who knows what awaits the microwave technology in the years to come.”

Capturing the Public’s Attention, Interest

Amana introduced the world’s first 115-volt countertop microwave oven in 1967. Geared specifically for consumer use, the product sold for $495 retail.

Because microwave oven technology was so unconventional, Amana executives sensed that the new product didn’t stand a chance in the marketplace without a massive effort to educate appliance retailers and consumers.

After a year-long effort of educating wholesalers and retailers, Amana launched the Radarange with a massive, nationwide media blitz that kicked off in Chicago. Amana invited reporters and homemakers to tour the city’s suburbs, while Amana hosts served coffee, reheated meals and made popcorn.

In addition, a specially trained home economist arrived at the homes of Chicago homemakers to help them install their Amana Radarange and cook the family’s first microwave meal. She was on 24-hour call for each of her clients for the first year of the launch. A serviceman also was on call, guaranteed to show up within an hour, if there were any problems.

The campaign was a success and the age of microwave cooking was launched. Throughout the 1970s, Amana continued to improve the microwave oven, adding new features, and improving the microwave’s cooking capabilities.

Today, Amana markets a variety of microwave ovens with up to 1,000 watts of cooking power and a wide array of conveniences. Portable, efficient, safe and economical, few gourmet or fast food cooks of the 1990’s can imagine life without a microwave oven.

For more information on Amana appliances or to locate your nearest dealer, contact Amana at 1-800-843-0304. Or, check out the Amana web site at www.amana.com for additional product and service information. (ARA)

Founded in 1934 in Amana, Iowa, Amana Home Appliances offers a complete line of products that generations have come to trust for their timeless design, craftsmanship, performance and innovation. Amana appliances, which include refrigerators, freezers, ranges, wall ovens, cooktops, Radarange® microwave ovens, dishwashers, washers and dryers, room air conditioners and dehumidifiers, are sold by major retailers and independent appliance dealers across the United States.

Editor’s note: Interviews with Dixie Trout, Amana vice president of consumer communications, are available by contacting Stephen Dupont, Carmichael Lynch Spong, 612/334-6235, or by e-mail at sdupont@clynch.com.

Courtesy of Article Resource Association, www.aracopy.com.

Happy Birthday, Amana
By Norman Remich

Having debuted in 1967 in Chicago "as a product that would forever change how Americans eat and cook," the Amana Radarange is celebrating its 35th birthday.

The Amana Radarange is celebrating its 35th birthday. It debuted in 1967 in Chicago “as a product that would forever change how Americans eat and cook.”

Today, more than 95 percent of American households own a micro-wave oven, and 75 percent of those surveyed by a recent Yankelovich Monitor study ranked the microwave oven as “almost impossible/pretty difficult” to do without. Only the automobile ranks higher.

The first Radarange featured a 115-volt current and just two buttons, start and light (on/off). It also included two control knobs, one for cooking times up to five minutes, and the other for longer cooking times up to 25 minutes.

Thirty-five years later, the Classic Radarange features 1,100 watts of power, 11 variable Cookmatic power levels, eight changeable preset Auto-cook options, and two changeable favorite message pads.

The Convection Radarange, the latest model (shown), provides 1,000 watts of power, a stainless-steel interior, Touchmatic Control System, four convection cooking options, and nine sensor cook options.

Amana is a unit of Maytag Corp., Newton, Iowa.

Norman is AM's executive editor.


   Learn about Winfield Salisbury in the late 40's and the Microwave Oven At Iowa State Fair


Engineer Bob Snyder With the Microwave
Oven 'Works' Display he built for the museum.

Close up of the Magnetron used in the oven assembly on display.

An interesting Link on questions and answers about microwave ovens can be found at: "How Things Work: Microwave Ovens," Louis A. Bloomfield, http://landau1.phys.virginia.edu/Education/Teaching/HowThingsWork/microwave_ovens.html



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