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Re: New member with some questions looking for answers

Hello Skip,

> My name is Skip Greiner. I built my first coil at age 10, a little over
> 50 years ago. I am finally able to really get into coiling again and
> am glad to be a part of this group.

Glad you're back into coiling.

> My most recent coil has the following specs:
> Primary: 5 turns .25" copper tubing 18" diameter
> Secondary: 288 turns #16 ga stranded machine tool wire on 12" x 36" form
> Break: 1800 rpm synchronous  4 gap
> Cap: .013
> Neon Xformer: 12kv -at- 60 ma
> Top cap: 18" toroid sometimes used with an 8" ball
> Discharges: nearly 48"

Am I reading this right?  You are getting almost 4' discharges with only
720 VA input?  That is 180 VA per foot of spark!  Or is there more than
one of these 12 KV -at- 60 mA transformers powering this coil?  Perhaps 2
of them?  If it is only one transformer, you are the king of output
efficiency, by far.

> The problem: I want to increase the power input. I have attempted to
> use 15 kv 120 ma neon as the source. I changed the cap to .021 and
> the primary to 3 to 4 turns. Resonance of the primary can be set very
> close to the original resonance of the the 5 turn primary with a .013
> cap. The discharges will not surpass about 42".

It could be a coupling problem, or lack thereof.  Have you tried tightening
up the primary/secondary coupling.  Since you have reduced the number of
turns, you now have less coupling.  If it were me, I would do one of two
things (or a combination of the two) to increase the coupling.  1:  Reduce
the capacitance and increase the turns on the primary and readjust the
coupling height.  Load the secondary with a larger toroid to reduce the
operating frequency and increase the number of turns on the primary.

> Question #2: Has anyone attempted to use refrigeration oil for caps.
> This stuff is highly refined and the cost is around $10.00 per gallon.
> A local refrigeration dealer sells a brand called Suniso 3GS.

Actual transformer oil is available for about $25 per 5 gallon pail.  It is
the better choice.

Just a couple of suggestions,
Scott Myers