Original poster: "Terry Fritz" <twftesla-at-qwest-dot-net> Hi Mark, See the tables at: http://hot-streamer-dot-com/TeslaCoils/Misc/NSTStudy/NSTStudy.htm It depends on your transformer size and if your gap is static or sync. Cheers, Terry At 10:37 PM 7/17/2001 -0400, you wrote: > > Could some one give me the formula to calculate what a 120bps cap size should > > be? > > Mark