On 5/6/24 11:28, Wayne S via cctalk wrote: > You do need a very strong magnet. I’ve put 3.5 floppies on top of a mag tape > demagnitizer ( not technically called that, but you know what i mean) and it > had no effect at all. I could still read them fine in my pc. I surmised that > the magnetic field generated was not strong enough to get through the plastic > disk shield. Gave up after that.
I made my own PM demagnetizer (I do own a bulk videotape eraser also, but this one is so convenient and works very well). The trick was to use two magnets with like poles facing. I got the magnets from a magnetron--it took a fair amount of clamping to get the things set in place. Unlike poles facing doesn't work, BTW. https://i.imgur.com/MUKTExa.jpg --Chuck