Steve Ward's mini coil:

 Steve Ward of Oak Forest IL, (US). Elevation 700 feet.  Email : srward16@

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: