Original poster: "by way of Terry Fritz <teslalist-at-qwest-dot-net>" <Beans45601-at-aol-dot-com> I am currently building a 9" coil. My power supply is 14.4 KV 1.5 KVA (probably going to run at 2KVA) and I don't have my cap sorted out yet. I am planning to use a 15,000 RPM ARSG. What size top load should I use? I was thinking of 18" across. But, how thick should it be? Thanks Adam