HV Input Power: Input power is provided by a 15kV 60mA Neon Sign Transformer, manufactured by Magnetek Corporation. The secondary winding impedance at 60Hz is approximately 300,000 ohms.

Tank Capacitor: The tank capacitor is an MMC design, and uses 240 Philips KP/MMKP polypropylene pulse capacitors. Each capacitor is rated .0062uF @ 2kVDC. There are 20 strings of 12 per string, which gives a final value of .01uF @ 24kVDC. Measured capacitance is .0111uF, which is within the 5% tolerance rating. Z @ 60Hz = 300k, and since the transformer's secondary winding is of equal impedance, a resonant condition exists.

Primary Coil: As seen in the above photographs, the primary coil lies within an enclosure. The enclosure is made of lexan (polycarbonate), and has been painted gray. The actual primary winding is 10 turns of 8 gauge THHN insulated wire. The inside diameter is approximated at 6.5", giving a 1" primary-secondary clearance. The reasoning behind the enclosure is aesthetics.

Secondary Coil: The secondary coil is 1000 turns of #24 gauge magnet wire, closewound onto a 4.5" x 22.0" white PVC form. Actual winding length is 21". The winding is sealed with one coat of epoxy, and three coats of Minwax brand polyurethane.

Spark Gap: All materials for the spark gap were purchased online from McMaster-Carr Supply Company. The gap consists of 6 electrode holders bolted onto a grade G3 fiberglass baseplate. Alloy 360 brass was used for the electrode holders, for its low cost and machinability. The holders were fabricated from 1.0" bar stock, and the electrodes themselves were fabricated from 3/32" tungsten rod. The air gap spacing is adjustable from zero to 3/4".

Topload Capacitance: Since the primary coil is not tappable due to the enclosure around it, topload size is very critical to coil performance. The coil system was designed to be tuned with a 7" O.D. sphere as the topload. The topload is fabricated from a 7" foam ball, and wrapped with strips of aluminum tape for conductivity.