The Specs of my coil:(in metric an american mass-system) Metric ------ Secundary: 10.6cm diameter polypropylen tube with 1120 turns of 0.3mm (AWG28) isolated Cu-wire on a length of 39cm Total length: 373m inductivity 31.8uH Primary: 4mm^2 (2mm diameter) isolated solid Cu-wire invere cone shape with 30deg angle mounted on wood Inner diameter 20.8cm Space between turns (incl. wire) 1.5cm tape point 13.3 (Sphere), 14 (Toroid), or 17 (both) Total length: 23.5m Caps: 12 bottles (beer 5dl) with saltwater. alu-foil total 7.0nF Topload: - sphere diameter 15cm (8.3pF) - toroid 25cm x 7.5cm (10.4pF) or both sparkgap: double static gap 2x0.3cm with carbon for cinema projection chokes: 2x2 200turns (5 Layers) of 0.4mm isolated Cu-wire savetygap: 2.5cm Powersource: 2 Neon-Trans 6.8kV 50mA in serie -> 13.8V (680VA) primary on 230V AC 50Hz Frequenz: 226kHz (sphere), 212kHz (toroid), 175kHz (both) Sparc length: max. 50cm american mass System -------------------- Secundary: 4.2" diameter polypropylen tube with 1120 turns of AWG28 isolated Cu-wire on a length of 15.3" Total length: 1223ft inductivity 31.8uH Primary: AWG12 isolated solid Cu-wire invere cone shape with 30deg angle mounted on wood Inner diameter 20.8cm Space between turns (incl. wire) 1.5cm tape point 13.3 (Sphere), 14 (Toroid), or 17 (both) Total length: 77ft Caps: 12 bottles (beer 5dl) with saltwater. alu-foil total 7.0nF Topload: - sphere diameter 5.9" (8.3pF) - toroid 9.8" x 3" (10.4pF) or both sparkgap: double static gap 2x0.12" with carbon for cinema projection chokes: 2x2 200turns (5 Layers) of AWG26 isolated Cu-wire savetygap: 1" Powersource: 2 Neon-Trans 6.8kV 50mA in serie -> 13.8V (680VA) primary on 230V AC 50Hz Frequenz: 226kHz (sphere), 212kHz (toroid), 175kHz (both) Sparc length: max. 20"