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First light for an old coiler



Original poster: "Dave Kyle by way of Terry Fritz <twftesla-at-qwest-dot-net>" <dave-at-kyleusa-dot-com>

Just thought I would give all of you an update on my coil project that this
list has helped make possible. I first joined this group in July after a 30
year hiatus from coiling and was stunned to learn of the advances in design
and construction that many of you have pioneered.

I initially was going to build a small 4 inch coil but being encouraged by
what I read and the chance discovery of a supplier of 6 inch thin wall PVC
in my area I changed my plans. So my redesign has the following
specifications:

3 x 15 KV at 30 ma Transco transformers
140 uf PFC capacitors
Standard neon protection circuit (less MOVs)
SRSG using .1 inch Thoriated Tungsten electrodes with a static safety gap in
parallel
.03 uf at 70 KV Maxwell capacitor bank
13 turns .25 copper tubing primary currently taped at turn 9
6 inch PVC with 36 inches of #22 wire secondary
24 inch spun aluminum toroid

Having very nearly completed every component I was anxious to test the
various pieces out. I can report that 15 KV at 90 ma makes an excellent
Jacob ladder. It makes a very strong spark and is quite satisfying given the
simplicity of construction. The PFC capacitors make a significant difference
in the currant draw going from about 16 amps to 9 amps with the addition of
the PFC caps. Despite the equations predicting the need for a higher value,
140 uf for 3 15 KV at 30 ma neons, as Terry has said, seems to be about
right.

As I mentioned I had planned for a smaller coil and had already purchased
1600 feet of 24 gauge wire so I figured it would be good practice to wind a
"bring up" secondary to test the winding jig I built and allow for some low
power testing. The winder worked great but regrettably the 24 gauge wire
only yielded a 16 inch high, 6 inch secondary (I am now thinking I was
shorted on that wire order) which is way too short for anything but very low
power testing.

My brother just finished machining the G3 SRSG disk for me and it is "in the
mail" so at the moment I an operating with a simple static gap. I also have
a temporary Earth ground driven about 4 feet in very wet ground (I am built
on bedrock so my ground rod will have to be driven horizontally) and tested
to be within about 3 ohms of the house ground.

Having carefully wired everything up for this test configuration I was
delighted to see 10 to 12 inch power arcs to a grounded object at just over
half power on my Variac. In the absence of a nearby grounded object to
strike I experience numerous hits to the strike ring and even on occasion
the primary. There was also considerable corona and arcing across the
surface of the secondary. As I indicated I expected some issues with such a
short coil. Still it was cool that with no tuning and at very low power the
components seem up to the challenge.

I expect the new larger 36 inch secondary will be completed by next weekend
along with the SRSG. This will undoubtedly take things to a new level of
power and I will be sure to get some pictures on my website for you. I am
hopeful with the larger secondary many of these issues will resolve
themselves. Your comments regarding potential control of the secondary
arcing would be most welcome.

Regards,
Dave

Note: I did find my garage door controller to be completely locked up after
testing. Fortunately when I cycled power it came back to life. I suspect the
proximity to the discharges were not to its liking. In future I intend to
unplug it while testing.



=========================================
Dave Kyle
Austin, TX USA
Email: dave-at-kyleusa-dot-com