Ed Sonderman's mini coil:
NST: Franceformer 4kV/20mA, 5 shunts removed top and bottom. Measured Isc current = 46 mA. 4,000 v x 46 mA = 184 VA
NST primary operating voltage = 118VAC.
Tank capacitor: Two Maxwell .035 ufd caps in series for a total of .01528 ufd.
Primary: 13 turns of # 10 bare copper wire. Inside diameter 5.8". Spacing between turns .35". Tapped at turn # 6.7. Flat spiral.
Secondary: Three inch diameter acrylic form wound with #28 wire for 13.1" winding length
Spark gap: Two 1.5" dia. x 4" long copper pipe sections mounted .050" apart. Small microwave oven fan for cooling.
Top load: Two toroids - 1" x 9" mounted on top of secondary, 1" x 11" mounted on top of that with 2" metal spacer between them.
Max spark length 10.75" using a breakout wire on toroid, discharging to a grounded wire. Location is Spokane, WA, elevation 2400 feet. Elevation derating factor has not yet been applied or determined.