Found a big older microwave in alley. Took it apart (mainly with cordless drill screwdriver and Phillips bit). I understood that the magnet tube had magnet in it. I got 2 fairly strong magnets out of it. They were about the size of a very large, very thick washer. That is: ring shaped, flat. I'm guessing that more modern microwaves will have smaller, more powerful (maybe some new-age alloy?) magnets in them. I also kept the fuse and the impressive, sardine can looking capacitor. Set the rest of the pile back in the alley by the dumpster.