On Wed, 26 Mar 2008 04:15:20 -0700 (PDT), Artem
wrote:

What material is used in the ferrite?

For transformer - low magnetic permeability (50) for chokes - high.

Unless you can be more specific, this sounds like the wrong material
(which you have not specified - do you know what you used?).

73's
Richard Clark, KB7QHC