The bigger cores are on back order so they want come soon
But from the 3k9 source measurement one can extrapolate the freq response of my toroid with a 220r source impedance, I know the high end behavior is more complex than a low pass filter, besides capacitance it has leakage inductance etc... it has self resonanse I cant see.
In the low end the -3db is at 2Hz because inductance rises at low Hz to 16 H.
At the high end the measurement indicates -3db roll off at 120KHz
Would it be correct to calculate self resonance freq. by having total capacitance from freq plot: 5n8 + measured leakage inductance?