Re: air blast gap

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Cydesho-at-aol-dot-com>

I'm running my coil off of a 15 kV 60mA NST. I had been using until very 
recently, and gap that consisted of two large brass balls, and a fan out of a 
microwave oven. The fan didn't really have enough oomph to work that well, 
and the balls allowed the arcs to get pretty long. Most of the arcs would be 
located at the center of the gap, but the airflow would carry them outward 
away from the gap. Consequently, there would be an arc that looked like a 
loop extending from the two electrodes. I recently replaced my old gap with 
another airblast gap. The electrodes are 1.5" copper pipe end caps, and the 
source of air is a hair dryer motor. The gap has improved the spark length 
coming of my toroid, when it's actually firing. The abrupt edges of the 
copper end caps have eliminated the looping arcs, and I have been pleased 
with the increase in spark length. I'm thinking that my gap might be suitable 
for conversion into a triggered gap. It would probably increase its 
reliability. What is the SD gap? I don't think I've ever seen plans for it.
                                    Justin