Original poster: "Jolyon Vater Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jolyon-at-vatercox.freeserve.co.uk> Is it possible in theory to build a tesla coil in which only a single inductor and the topload/ground capacitance forms the entire tuned circuit? the lower end of L1 being connected to the excitation source which might even be a spark gap -although I understand the latter is risky!