Couldn't find the frequency on my microwave oven, but I did find the air inlet clogged with dust! Cleaning that should improve the oven's efficiency and extend it's life.
yellowstone national park -- 9/12/14
""Yellowstone, it turns out, is a supervolcano. It sits on top of an enormous hot spot, a reservoir of molten rock that rises from at least 125 miles down in the Earth. The heat from the hot spot is what powers all of Yellowstone's vents, geysers, hot springs, and popping mud pots. ..."
Yellowstone's vents, geysers, hot springs, and popping mud pots are interesting.
The last time I visited Yellowstone was before I knew it was a supervolcano, but that won't stop me from visiting it again.
But if that sucker blows again, we're all in for trouble.