Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ArcStarter3-at-aol-dot-com> Hi, Are you using ceramic/doorknob capacitors? Kinda sounds like the caps are heating up and the capacitance is drifting, throwing the coil out of tune... Regards, Josh Hunsaker ---------------------- Denver, Colorado ArcStarter3-at-aol-dot-com