Weird coil behavior

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Sean Taylor by way of Terry Fritz <twftesla-at-qwest-dot-net>" <taylorss-at-rose-hulman.edu>

Hi all -
I was running my coil last night, and decided I wanted a little longer
sparks and pushed it to the limits, so I added one more gap to my RQ type
gap.  Took a little more on the variac to get it to fire, as expected, but
when it did fire, It seemed like I got arcs through the _inside_ of my coil,
and from the secondary to the primary.  But these weren't like normal arcs
from a coil, they fired like a HUGE discharge of energy, making an
incredibly loud noise when the did occur.  After seeing all of these things
happening, I shut it off, and lowered the # of gaps back to normal.  Brought
the variac up again and . . . nothing.  just transformer humming, a little
crackle noise from the gap like corona.  I kept reducing the gap size until
I was at one gap (about 0.030") and then it would fire with a high setting
on the variac, but no output from the TC.  I disconnected everything, and
checked each component (transformers, cap, primary connections, etc) and
everything was fine.  There were no carbon traces through the PVC secondary,
but there was a burn through one turn of the secondary, basically acting as
a shorter turn.  Shouldn't the gap still fire?  Anyway, here are the specs
of my coil . . .

4 x 15 kv, 30 mA NSTs
Rolled PE cap, ~0.02 uF (I know its small, I'm getting a new cap soon)
RQ style gap, ~0.03" per gap, 5 gaps when problem occurred
inverse conical primary (~20 degrees), 1/4" copper tubing, 1/2" CTC spacing
6" PVC secondary, 22 Ga. wire wound on about 28"

Thanks in advance for any help!
Sean Taylor