I built my medium size spark gap Tesla coil. Power suply is single microwave oven transformer with voltage quadrupler, it steps up the voltage 4X so at the output I get about 8,5kV DC. As I result, I was needed to build DC resonant circuit which contains inductor, some HV diodes, ant TC primary circuit. Capacitors were made of beer bottles, so they causes big energy loses in primary circuit. As a result, my Tesla coil now produces between 25 and 30 cm arcs. But I'm building new capacitor of glass plates. When capacitor will be made, I'll put capacitor into plastic box and fill it with food oil, that's because it increases the capacitence. Ok, that's enough of bla bla bla, let's view the first light of new TC.