John Popelish wrote:
You'll learn a lot by reading the information in the Fair-Rite
catalog, available at their web site.

I have a hard copy right beside me, and refer to it often.

I also have a fold-up brochure from Amidon dated March 1991
and titled: "Iron-Powder and Ferrite Coil Forms".
--
73, Cecil http://www.qsl.net/w5dxp