I recently had a magnetic stripe on my bank card fail and I was curious to find out the exact nature of the corruption which would require scanning the surface of the stripe and determining its magnetic characteristics.
I was wondering if there is any simple setup that would allow me to just use a probe and make a map of the magnetism of the strip? Note that I do have a cast iron X-Y table which has dials calibrated in thousandths of an inch. So, it is easy for me to locate the probe to that degree of precision.
I assume that there is way to do it, because I know in the old days there were these things called hard drive "microscopes" that had some kind of needle and you could literally read the bits off the disk platter, bit by bit, with the microscope. But, what I don't know is how easy it is to make the "needle" part of such an apparatus. Is this really simple, or would it be a complicated project?