Sorry I missed this experiment in post #29 when you first posted it. I just now saw it.
Very nice experiment, however if I may, I would like to offer some suggestions for a more refined test.
Instead of a pot core, use a rod core or piece of 2 inch ferrite cut from a flyback transformer with square cross section.
The leads should be attached with conductive epoxy, (preferably silver) at two distant points on the rod on opposing faces.
The assembly should be put into a small aluminum box with BNC connectors at either end and 50 Ohm termination resistors.
Do not use probes, use BNC cables to connect to the generator and scope.
The test can also be repeated with a bar magnet instead of a ferrite rectangular rod.
I'll work up a sketch for you. Termination and shielding is important at these frequencies, and probe ground clips can pick up stray signals or be resonant loops at certain frequencies, so should be replaced with BNC cables terminated to 50 Ohms inside the shield box.
Thank you for doing this experiment. My generators lack the sweeping capability, and my 300 MHz scope is in repair with a triggering problem or I would try to duplicate this experiment. I am sorry that I cannot do the fine level of testing you are able to at this time because of equipment shortcomings. May be time for me to buy some new gear.
I got the idea from a video I saw where a fellow took a cut half section of a ring magnet (speaker magnet) and he attached leads to either end, four in all at distant points on the magnet section two connections at each end on the faces and was able to light a LED at a specific and very sharp frequency point. That video was later removed from youtube.
I thought this might also be used to characterize a ferrite resonance.
Thank you, Itsu for following up on this.
Kind Regards ION
Just because it has a patent application or is patented does not always mean it really works.