BIG coil project

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "David Rieben" <drieben@xxxxxxxxxxxxxxx>

Hi all,

I'm starting to get together some of the basic parts for my biggest coil
project to date. I have just completed a 12 x 56 toroid made from 4
pieces of 12" aluminum flex-duct that each had a compressed length
of 24". The secondary is ~897 turns of non-spaced # 17 AWG heavy
build, Essex magnet wire, wound on a 12.75" OD form for a total wind-
ing length of 44". It's a little short for the spark length that I'm shoot-
ing for, but with that massive toroid, it should work. Looks like a mini-
ature Wardencliffe :^) The power transformer will be either a 10 or a
15 kVA, 14,400 volt pole transformer unit and the control/ ballast as-
sembly is (2) paralleled 1256D powerstats in series with the core of
a 225 amp stick welder, set at maximum current. I can get a little
over 100 amps current flow if I turn the variacs all the way up (280
volts input to either pole pig, that's set for a Jacob's ladder) for a short
run. I have (2) .1 uFd, 50 kV commercial pulse caps that I can use
for the primary cap and I was thinking of starting off with just one
(.1 uFd). The primary is 12 turns of 1/2" copper tubing and it sets
a 2 to 3" below the plain of the lowest secondary turn. The outer-
most primary turn is about 40" in diameter. I will be using a G-10/
tungsten rotary gap that I still have yet to aquire. I was wondering if
maybe a few of you guys with the coiling programs could run the
numbers and tell me how well this will work and what I could expect
as far as spark legth output and where the primary coil would be tapped.
I was hoping to be able to make up to 15 foot sparks with this setup
and I know that R. Hull's Nemesis had a 14" dia x 46" tall secondary
with a really large top-load and it made 15 foot sparks. I can't recall
the size of his top-load, but it looked to be in the size range of my
12 x 56 one. Should I use just one of the .1 uFd caps or both with
for .2 uFd with this massive of a top load? Any comments appreciated.

Thanks,
David Rieben

PS- The bottom of the toroid is only about 6" above the upper-most
turn of the secondary, so I don't think that I will need a smaller second
toroid underneath the big one. What do you guys think?