|MadSci Network: Engineering|
Yes, home microwave ovens do lose power over time. There are several reasons for this: These days, many electronic devices are all solid state--using transistors, integrated circuits, etc--instead of vacuum tubes. But microwave ovens still utilize a specialized vacuum tube, called a magnetron, to create microwaves. These tubes age due to many factors including oxidation of the metallic elements within the tube, and destructive feedback which occurs when some of the microwave energy is not absorbed by the food (load) in the chamber, but reflects back into the magnetron tube. A patented device called an isolator can help prevent destructive feedback. It places a device in the waveguide which deflects the reflected raditation away from the tube. More details are available: www.cemx.com
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