It might have had something that can shift its frequency.
What happens in most microwaves is you get a standing wave. The high and low parts of the wave are always at the same spot. You then get a hot spot at the peak (and trough) of the wave, and a cold spot when the wave is near the zero node.
By shifting the frequency, even just a little, you can shift the hot spots around and more evenly cook the food.
This is obviously more expensive, and these days you can get it in higher end residential microwaves. Way back when, though, it was only something you’d see in industrial models.
If I’m thinking about it correctly then either the standing wave is intentional or the oven is designed badly. You know the wavelength so you can make sure the oven is not an integer multiple of it and the hot spots move around on their own, no fancy frequency shifting required.
It might have had something that can shift its frequency.
What happens in most microwaves is you get a standing wave. The high and low parts of the wave are always at the same spot. You then get a hot spot at the peak (and trough) of the wave, and a cold spot when the wave is near the zero node.
By shifting the frequency, even just a little, you can shift the hot spots around and more evenly cook the food.
This is obviously more expensive, and these days you can get it in higher end residential microwaves. Way back when, though, it was only something you’d see in industrial models.
If I’m thinking about it correctly then either the standing wave is intentional or the oven is designed badly. You know the wavelength so you can make sure the oven is not an integer multiple of it and the hot spots move around on their own, no fancy frequency shifting required.
It’s not entirely by choice. There’s a limited range of frequencies available.