I have a magneto optic sensor that can visualise the field lines of a magstripe when using a polarising microscope - https://www.youtube.com/watch?v=c8nM4Z-hkTw

I have a magneto optic sensor that can visualise the field lines of a magstripe when using a polarising microscope - https://www.youtube.com/watch?v=c8nM4Z-hkTw https://www.youtube.com/watch?v=c8nM4Z-hkTw I'm going to try a VHS under it, to see what I get.