Re: Grounding Problem???

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

Original poster: "Marry Krutsch by way of Terry Fritz <twftesla-at-qwest-dot-net>" <u236-at-earthlink-dot-net>

Hi John, Scot, All

	I have tried loosening the coupling quite a bit.  To get rid of the
racing sparks the coupling must be around 0.08.  Spark length is pitiful
in that case.  I have tuned the coil as well as I can.  The tuning point
is about 1.5 turns in from the calculated point.  Moving the tap just
decreases spark length.  I am running a 6 inch coil using two of those
GE copier xfmrs for a supply.  I'm using a 0.1 uF cap, for a bang size
of approx. 5 joules.  My specs are in the "Help! suicidal secondary"
thread, except that I'm now using a smaller toroid of 6" by 22".  I
tried a 0.066 uF cap, but racing sparks remain.  Spark length goes in
the toilet too.  On a good humid night, I can get a few 6 ft. strikes to
the ground.  Dry nights give short streamers, and long racing sparks
:-(.  I can't believe that I could be overpowering an epoxy coated 6 by
28 inch secondary with 1600 VA.  I wish I had pictures of the secondary
for everyone to see, 'cause it looks ridiculous with those insulating
washers on it!   Maybe I should give up and build a new system.  Any
suggestions?  BTW, I did all the math for this coil (more than I needed
to, actually), and everything looked fine.

Thanks
Tesla list wrote:
> 
> Original poster: "BunnyKiller by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<bigfoo39-at-telocity-dot-com>
> 
> Tesla list wrote:
> 
> >Original poster: "Marry Krutsch by way of Terry Fritz
> <twftesla-at-qwest-dot-net>" <u236-at-earthlink-dot-net>
> >
> >Hi everyone.
> >
> >       I've been doing a bunch of reading, and found that most people have
> >extensive RF grounds (compared to mine, anyway).  The problem with my
> >secondary hasn't really gone away, and I have 1/8 inch of epoxy coating
> >on the thing.  I still get racing sparks, and now I have arcs (very hot,
> >thick) breaking out of the corona ring to the strike rail.  Is the
> >corona ring actually supposed to contact the secondary, or does it sit
> >there "suspended", w/o contact.  Anyway, My RF ground is 8 Al stakes
> >stuck 18 inches into the soil, with 12 gauge solid wire connecting
> >them.  I then use one strand of solid 12 gauge wire to connect to the
> >coil, 15 feet away.  I use bend a hook into the wire, and connect it to
> >the secondary with a nut.  I water the ground before firing the coil.
> >I've read that bad grounding can cause secondary breakdown.  I'd like an
> >opinion or two before I spend money on more material.
> >
> >My posts may not reflect it, but the help I've gotten from you guys has
> >been a tremendous help.
> >
> >Thanks,
> >       Winston K.
> >
> >
> >
> >
> >
> 
> Hi Winston ...
> 
> sounds like you have the grounding "problem" solved  ( btw what size
> coil are you running ??  NST or Pig?? ) ...  altho you may want to try
> something a bit heavier than 12 Ga. going to the rod system
> 
> what you seem to be dealing with now is something called close coupling
> ...   the primary is putting too much energy into the secondary ....
> try raising the secondary about 2 inches, leaving the primary in its
> original position....  if that doesnt reduce the secondary arcing ....
> try tapping the primary about one more turn in or out ...
> 
> Scot D