proofing NSTs

["by way of \"Terrell W. Fritz\" <terrellf-at-xxxxxxxxxx>" <Parpp807-at-xxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

>>Forwarded from a note to me from Ralph. - Terry<<

Hi Terry,
Please help me with a problem I'm having with the two paralleled NSTs driving 
my bipolar.
When I left the coil in the spring for outdoor pleasures the coil was 
throwing a 20-inch
spark between terminals, and beautiful 12-14 inch streamers.  With 20-inch 
spacing
between the 1/2 wave terminals the voltage was high enuff to run a 14-inch 
leaker
down the side of the wooden supports towards a nail. Very nice. When I fired 
it up again in October, the coil had completely wimped out to maybe an 8-inch 
spark.   :-((

The MMC is good. I can check it on the LCR bridge and I have a nice CD Type 
KVX
0.0223 uF -at- 35 kV to substitute.

Although nothing was touched during the summer, I have been playing with the 
NSTs.
The NSTs are one France 15/60 in parallel with a France 15/30. I use 52 uF of 
PFC.
This system worked fine. I know how to phase the transformers but I'm not 
sure I know how to check the 1/2- winding to case ground. I assume I should 
get a hot arc to case
ground and across both ends of the secondary. All check out.

The only udder thing I can think of is that a winding is failing under load. 
Is there a 
way of testing this? Is there a way of proofing the NST?

Thanks.
Ralph Zekelman

You're certainly welcome to post this to the list if ya wanna.