Hi Fred,
I appreciate the feedback. I will eventually post a link on some other forums.
I don't happen to have any mix 52 in my collection or I would have tested it. Looking at its complex permeability, I can see why it might be favored. The lower permeability allows there to be more turns on the primary, which will imply a lower B field for the same primary inductance -- That is probably a good thing for less loss. The competing issues would be larger leakage inductance and more winding capacitance...
Cheers,
Gary AF7NX
