Hi Coilers, Maybe this is old news for the real TC die hards, but I found some interesting stuff about skin depth on <http://www.misty-dot-com/~don/skin.html>http://www.misty-dot-com/~don/skin.html. Thank you Don Klipstein! I must still read his info carefully, so I can't comment on it right now, but I'am really interested in the general opinion of the list members about this paper. Ruud de Graaf Greetings from lovely and wet Holland