Original poster: "Mike Veldman by way of Terry Fritz <twftesla-at-qwest-dot-net>" <vmike-at-email.ceat.okstate.edu> My rough penciling of the self resonant freq for your coil without any capacitive top hat is about 215khz. There is a pretty useful tesla coil calculator at http://www.classictesla-dot-com/java/javatc.html you mught look in there. mike