Re: 1st Tesla Coil

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

Original poster: "cd by way of Terry Fritz <twftesla-at-qwest-dot-net>" <vbprg1-at-hotmail-dot-com>

Ok youll get better advice than this but

You may need a few more electrodes...in your spark gap I think 9 is the
recomended number
I also think youll need to blow air over your spark gap....

I built a vacum motor suction gap with 2 electrodes and some pvc mounted on
the the suction part of a vacum motor I salvaged.....It seems to work
great...though I have no experience with a rotary gap...and my research led
me to believe a suction gap would be not only easier to build than an
ajustable AIR BLAST series type spark gap, but would function much
better....

I am also wondering how you got so many winds of 26 guage on that size form
I used #26guage magnet wire on a 4" od coil
when I actually counted the turns....
I got 960 turns on a exact 4" od coil form with 20 inches of wraping...
you can count how many turns are in a 1/16 of an inch or an 1/8 and multiply
to find out
your actual total of turns....

You may also have a lot better luck with a second NST....
but you are going to need to find out what your capacitors measure...
you can get a digital mm from radio shack that measures capacitance for
80 dollars or so... It will at least give you an Idea of what your capacitor
measures

the resonant charging value of your capacitor should be
0.006631455961296416mfd
or .0066 mfd or uf
or 6.6 nf
if you increase your parallel another NST in with your 12kv30ma
youll get 12kv 60ma
resonant chargeing value for this is
0.013262911922592832 mfd
or .013 uf
or 13 nf
good luck.....

I got lucky on my first coil I got 2-3 foot sparks...with 2x 12000v 30ma
neons
just for reference....
I got 12 inch thick purple sparks out of 1x 12000v 30ma neon and an aluminum
can

our TC systems are actually very similar
and with some minor modifications you
should be able to do as good as I did....

it was pure luck and good advice from list.....
Chris Dowdy

ps Im not useing a protection filter nor chokes .... currently my NSTs are
being considered expendable...fairly cheep and available easy.....actually
looking for an excuse to remove some shunts more like it......





----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, August 08, 2002 9:07 AM
Subject: 1st Tesla Coil


> Original poster: "quezacotl GF by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<quezacotl_14000000000000-at-yahoo-dot-com>
> Hi Everybody,
>          This is my first post to the mailing list and one of my buddies
and I
> finished our first coil about a month ago. It took quite a while and with
a bit
> of help (thanks Greg) we got it completed. The problem is that we can't
draw
> anything from the coil without a grounding wire, and with it, we get all
of the
> corona we want but actual sparks are thin, weak, 6-7" sparks. I'm asking
the
> great and infinite wisdom of the tesla coil mailing list whether or not
this is
> the best our coil can put out, or if there's something we can do. Here are
the
> specs for the coil:
> Transformer: 12kV/30mA NST rated for 120 Volts. I am using the NST
protection
> filter seen at
> Capacitor: 7 - 16oz saltwater bottles. We've tried 8 bottles but it didn't
make
> much of a diffrence. ( I know MMTs are better, but I'm too poor to afford
> them.)
> Spark gap: 7 - 3/4" copper pipes spaced about 1/16" apart. Gap can be
widened
> or shortened if necessary.
> Primary coil: 15 turns of 1/4" copper refridgeration tubing spaced 1/4"
apart.
> Secondary coil: approx 1080 turns of #26 gauge magnet wire. Coil is
wrapped for
> 18.75" around a 3" diameter ABS pipe. Bottom of coil is connected to
ground via
> a piece of rebar drove into the ground.
> Toroid: 4" cross section aluminum flex duct. Outer diameter is 15.25".
> If you have any questions, advice, comments, or just want to make fun of
me for
> the fact that I can't build a Tesla Coil properly ( everybody else does )
then
> just email me at

> > Thanks, Chris