Steve Ward's mini coil:
Steve Ward of Oak Forest IL, (US). Elevation 700 feet. Email :
NST is 4kv 20ma France 4020SE.
Intended for catagory 1
Short circuit current: 1/2 shunts removed for 35.8ma. 4000V * 38.8 mA = 143 VA.
NST primary voltage is 120vac
Primary is about 6 turns of 1/4" copper tubing.
Secondary is 2.3" OD PVC with a 14" winding of 28awg magnet wire.
Spark Gap- single gap of 2 large copper pipe electrodes, maybe forced air. The pipes are .75" diameter and 5.25" long.
Cap is set at .019uf. Its made from a string of 17 caps. Each is .33uf 1200v GE 42l series. There is really 23 in series, but I'm tapped at 17.
Toroid is mainly a 2" x 10". It is vacuum cleaner tubing covered in foil tape. The small toroid is beneath is 1.25"x6".
I have completed the 5 minute run on the same day I achieved 13" sparks from 120v input at 35.8ma.
Longest discharge is 13"
My website is at: http://www.geocities.com/srward16/index.html