Safety Gap Firing

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Original poster: otmaskin5@xxxxxxx 

I'd sure appreciate some advice on this problem.  My coil seems to 
run fine as I dial up the variac, but as soon as it hits the 110 volt 
setting, the safety gaps start firing.  I've reverified the optimal 
primary tap point, so hopefully I've got the tuning right.

Here's some info on the coil that might be helpful:
   * 15/60 NST with a 35kv/0.03 uF Maxwell pulse cap
   * spark gap - air-cooled segmented pipe - 6 gaps @ 0.03" each - 
0.18" total
   * safety gap - 3 brass balls (1/4" dia.) - 2 outer balls 
connected to the NST terminals & center ball to ground.  The 
hot-to-ground gaps are 0.130" or 0.26" total.  This was the setting 
at which the safety gaps just wouldn't fire with only the variac & 
NST hooked up
It doesn't make sense to me that the safety gaps can fire when the 
spark gap separation is greater.  Any help for a struggling semi-newbie?

Dennis Hopkinton MA