Thanks Peter, Nice sites also. http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/igcoil.html and http://www.tortech.com.au/toranalysis.html Joe "Pip" Betz said that. jlb94 at juno.com ,-._,-. "Never argue with a fool - \/)"(\/ people might not know the difference." (_o_) http://community.webshots.com/user/pipbetz