Guys, we are running out of things to say on this topic. Most of these points have been stated before. We are stalled, needing some measurements of coils near to producing racing arcs so we can actually see what signals are present and at what level. I feel that lurking in this topic is something new and useful waiting to be discovered, hidden not too deep - and we have the technology too! We 'theorists' can only speculate ad nauseum until this ball returns from the experimenter's court. -- Paul Nicholson
Paul, There is a TC operation mode that can produce a great number of racing sparks all over the secondary. I don't remember anyone mentioning this but they may have. One time I was testing a static series gap under relatively high power. The gap was not cooled so it heated up fairly quickly causing it to either power-arc and/or quench poorly. When the gap was still cool, there were no racing sparks. As soon as the gap heated, a great number of racing sparks appeared. I don't remember if the output sparks decreased in length. I would imagine they might have. I would think that the peak capacitor voltage would be lower in this (over-heated gap) mode. I didn't actually scope the firing of this coil. I think I've seen other folks' coils which did the same thing but it seems to be something that hasn't been discussed much or at all on this list. Any thoughts or speculations about why this might happen?John