The Turn Of The Century Electrotherapy Museum http

Quenched Spark Gap Tests: Round One..
19. Sept 2007

Some crude tests with a Oudin Resonator and make-shift primary coil.

Coil form was 6 inch black ABS drain pipe. Approx 22" of winding, 18 AWG. Primary was 3 turns of 2" wide copper strap, 8.5" ID 9" OD,
insulated with electrical tape and shellacked mica.
Power supply: 2 ballasted MOTs with an output of 4000V approx. 375mA
Adjustable acetate/aluminum foil cap. Set to .032 for above photo, gap opened .015" wider than with photos below.
Discharge seen here is around 14".

Discharge to wrench. .02 mfd capacity.

Same discharge not to wrench. 8-10" brush.

.024 mfd
Click here for a movie!

Dual quenched gap using 3/4" diameter Tungsten

Side view showing gaps. Lower gaps are mounted to individual heat sinks, upper gaps are attached to a bridge pressed against a
6" disk heat sink / percussion plate