EMI suppressor(filter choke) for switching power supply on ferrite transformer core?

[asrock70]

I would like input chokes for switching power supply 200W transformer wound on a ferrite core.
I have 2 sector core E2005 with ferrite CF138 Al=1350 nH (ungaped core).
It is good idea for make 2x10uH EMI suppressor?

 

[jiripolivka]

How good an EMi filter is depends on ferrite features. The best results offers a bifilar- wound transformer with the coils connected to cancel the EMI components. The gap in ferrite core prevents saturation (at 200 W, the current is high).

You can certainly use 2x10 uH coils; filter efficiency depends upon the switcher frequency and harmonics.

 

[asrock70]

I wondered about
core two chamber E 2005S, ferrite CF138 witch g=0.5mm, Al=80+/-10nH. Make as current compensated coil 2x8uH (2x 10 turn).
EMI filter 8uH coil + 2 x 470nF X2 capacitor.