Re: Sync gap test 3

["Tesla list" <tesla-at-xxxxxxxxxx>]

Original poster: "Barton B. Anderson" <tesla123-at-pacbell-dot-net> 

Ed,

This sounds like you are saying that 120 BPS operation is too much for your
coil.
I can't see how. My gut feeling is that something else went wrong somewhere
between the break changes or the cap change. My guess is that either the tuning
or coupling was "way" off causing the initial breakouts and eventually
secondary
breakdown. Is the coil not repairable? If so, it would make a nice test coil to
identify the "real" problem.

Bart

Tesla list wrote:

> Original poster: Esondrmn-at-aol-dot-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