Spintronics,
1000 words...
the camera flash whited out the thin bubbles but they are there
used fine iron filings with epoxy core, 1000' 28ga secondary and chokes, unknown scrap primary, all copper
my iron wire will show up someday and I'll give that a try...
Tony, I can't seem to find the way to get the inverted phases on b+ and b- on my scope
kb