---------- Forwarded message ---------- Date: Sat, 11 Jul 1998 00:19:55 -0500 From: Shaun <shaunobrien-at-geocities-dot-com> To: Tesla List <tesla-at-pupman-dot-com> Subject: Formula's Anyone happen to have the formula for finding the inductance of a cone primary? I saw it once before but I don't remember where. Also I can't remember how to find the length of a sprial. I also need to find the length for the primary.