I once worked at a store that had a microwave that didn’t have a turntable. It wasn’t even the oldest piece of electronic equipment in the place.
Thats actually still a thing in the modern age. My friends have one like that. They got theirs new last year. Its also massive.
Was it any cheaper than a regular one?
No, they are more expensive, but it’s worth it because they are much better
Moving magnetrons are a thing these days.
Microwaves designed for public use often don’t have them. I never really knew whether it’s because they don’t need them because they have more magnetrons or something, or just because they prioritize easy cleaning.

Do you think this public microwave has a turntable ?

It looks like it’s hard to clean.

I’m going to start putting those signs on public microwaves…