I finally got one of the 9,000 Volt / 450mA transformer re-worked (and in time for the 4th of July). This NST together with my new 82nF capacitor and all of the toroids I own (used the small 4 inch toroid from the original confirguration (lower) and stretched my 8 inch toroid to 34 inches OD) produced the following results. I was able to get arcs to the floor, ceiling, walls, garage door, etc. I measured several of these points in the 63-67 inch range, but, of course, the coil usually tends to hit the closest object. I used the ground point set up as with previous results and the arc would go past the point, but never seemed to hit it. At one time the arc hit the plastic pipe that holds the point...even though the pipe is about 8 inches farther than the ground point and wouldn't seem to be nearly as conductive.
The coil tuned at about 10 turns on the primary and seemed to be somewhat sharper tuning than the previous configurations. I ran the 26 element gap using 16 gaps at .011 for a total of .176 inches. I got arcs from the toroid nearly the first moment the spark gap fired, so I'm sure that a smoother, larger toroid would help build more voltage as it did with the 40-51 inch transformation.
steps...12 inch toroid(s) ?!? Series transformers?