Silvio, tnx for responding :)
I have/planing use:
core 3C94, up to 300kHz, Ferroxcube,
IRFP460LC transistors,
Copper foil 0,1mm thick, isol.=Kapton on both sides, prim/sec isol.= Mioflex 0,15, 2x...
Any experience using Copper foil?
What sw. frequency is recommendet?