Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>" <Parpp807-at-aol-dot-com> In a message dated 3/29/01 6:15:13 PM Central Standard Time, tesla-at-pupman-dot-com writes: << Only a few coilers test their coils for resonant frequency during actual TC operation using a scope or frequency counter. >> John, Besides very carefully, how do I do this? Cheers, Ralph Zekelman