Sync gap test 3

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Esondrmn@aol.com 

I just put the 3.0" coil back to its original configuration.  The idea was to 
test to make sure the secondary is ok - after having sparks break out on the 
lower portion - then to switch to the LTR .032 ufd cap.  Now test for proper 
tuning with this cap then go back and try the sync rotary at 120 bps again.

Before running the coil, I did raise the secondary up to loosen the coupling 
so the lowest turn of the secondary is now 7/8" above the primary.  Running 
the coil now with the original components (.008 ufd cap and static gap), 
performance is not quite what is was.  I did see another spark break out a 
couple of inches up from the bottom of the secondary.  This is strange, as I 
have never has this problem before with this coil.  I don't have the 
equipment to measure the coupling, but I did not think it was overcoupled.  I 
disassembled the coil and inspected the inside, up from the bottom.  The form 
is clear acrylic as is the mounting base.  I can clearly see 4 burned spots 
inside - matching the spots that I had cleaned up and fixed on the outside.  
I think this secondary is done.  This is the first one that I have destroyed.

I guess the lesson here is that a sync gap running at 120 bps, using a LTR 
cap, put a whole lot of energy into the system - certainly more than I was 
expecting.  Next time, I will make sure the tuning is spot on by testing with 
the LTR cap and a static gap first and make sure the coupling is plenty loose 
before firing up the sync rotary.

Any other ideas to prevent this kind of problem?

Ed Sonderman