Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rblaisdell-at-juno-dot-com> my first coil is/was a 15/30 nst. Using a 4.25" light blue drainage pipe from "Tractor Supply" I wound 1000' of 22awg wire on it givine about 900 turns. My eventual sparks came out to be 36-40 inches after much work on the capacitor and spark gap. peace, Ry feel free to ask me off list.