Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com> We measured it once with small spheres. Output is 19.5 kV. Dr. Resonance > > My small Science First coil has an approx 1 inch spark length discharge to > ground. The frequency of the secondary is around 1 Mhz. What is the > estimated output and how would I determine it? > > Thanks, > Jack > > >