Original poster: Mddeming-at-aol-dot-com In a message dated 1/29/04 8:28:48 PM Eastern Standard Time, tesla-at-pupman-dot-com writes: Original poster: "Hydrogen18" <hydrogen18-at-hydrogen18-dot-com> How long should a 3 inch secondary be for 1200 turns? "A sufficient Length" Lewis Carroll "A convenient Length" Jonathan Swift "Wire thickness X 1.05 X 1200 + 2 inches" Matt D.