Re: fine tuning a secondary 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>

I was only sort of aware about the height of the secondary over the primary
had anything to do with tuning, but when I wrapped my secondary
I actually may have made another lucky error

I wraped about 20 inches of 26 guage on a 23 inch coil form.(1300 turns on a
4"od clear plexi)
so
the bottom turn of the secondary is 2 inchs from the bottom of the coil form
this already gives me about 1 and 1/2 inches above the primary
I also have a spark guard secondary mounting to prevent
secondary and primary oversparking.

I would like to say
I ran a few more tests and got about 15 - 16 inch sparks out of my
orange soda can, and all tests were only run up to 90 percent power. The
safety gap was set to fire when the variac reached 100 percent....

There was no detectable heat build up
in any of my components at least none I could detect after unpluging and
droping caps.
There was no static charge held by the secondary or at least none i could
detect.

I ran a test with a florescent bulb to determine EM field range and
after about 5 feet the bulb did not light up.

It seamed like I could have let the thing run
for several hours with no ill effects....
but about 10 to 15 minutes was my longest run
Is that a long 90 percent run?

I will soon post more pictures Lots of Information and tons of Links at my
page
http://home.earthlink-dot-net/~cdowdy2/

I do need more/any information you guys can spare about helping me fine tune
my secondary
so I can get it to work with my top load or torus.

A good queston is If my coil is close to in tune with an aluminum can
and I add a 16inch 4 inch torus from aluminum ducting....a much more
capacitive (is that a word?) topload
would I need to move the turning arm out along the primary
or in.....im guessing out to increase the em wave size to compensate for the
added wire effect from the torus...?????
Also another question is
Is my 12000v 30ma neon sign powersuply just to wimpy to break out on that
torus?
15 inch sparks with that ps cant be to bad for a first try :)

Wow! Building was easy Tuning is the HARD part
but I think I was really lucky during all of it...cause it works :)
Chris Dowdy


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, July 05, 2002 1:50 PM
Subject: fine tuning a secondary coil


> Original poster: "D.C. Cox by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<DR.RESONANCE-at-next-wave-dot-net>
>
>
> Now that you have your coil running and in a state of "tune" then you need
> to do some "fine tuning" by adjusting the coefficient of coupling between
> primary and sec. to achieve optimum performance.
>
> Try using some scrap 1/2 in. plywood wedges under the sec. coil to elevate
> it in 1/2 in. increments.  As you do there will be a "sweet spot" where
the
> coeff. of coupling is just correct to allow maximum energy transfer.
>
> It takes a bit of time but is well worth the effort.  It also allows yours
> caps to run without possibility of any destructive energy reflections from
> the secondary coil as it's magnetic field collapses.
>
> Best regards,
>
> D.C. Cox
>
> ----- Original Message -----
> From: "Tesla list" <tesla-at-pupman-dot-com>
> To: <tesla-at-pupman-dot-com>
> Sent: Thursday, July 04, 2002 10:28 PM
> Subject: Reporting
>
>
> > Original poster: "cd by way of Terry Fritz <twftesla-at-qwest-dot-net>"
> <vbprg1-at-hotmail-dot-com>
> >
> > Hello everyone
> >
> > I would like to report SUCCESS
> > with 1x 12000v 30ma NST  at 90 percent power on the variac
> > I have created 12inch sparks
> >
> > I am still narrowing in on optimal tuning but here is what it took
> > perhaps this will help someone else
> > all tests run up to 90 percent power
> > test1
> > tap 12 turn  TOPLOAD large torus- no sparks weak glow in f tube
> > test2
> > tap 10 turn - TopLoad Aluminum pan- very small sparks
> > test 3
> > tap 12 turn TopLoad aluminum pan - no sparks
> > test 4
> > tap 8 turn Topload aluminum pan - no sparks
> > test 5
> > tap 10 turn Topload aluminum can - 2-4 inch sparks
> > test 6
> > tap turn 11 Topload Aluminum can - no sparks
> > test 7
> > tap turn 9 TopLoad Aluminum can - 10 - 12 inch lightning :
> >
> > Further testing remains to be done with the 4 torus's I have built
> > but I thought you guys might like to know
> > I GOT MY FIRST COIL TO MAKE LIGHTNING
> > WHOOOOOOHOOOOOOOO
> >
> > Thanks for all the great information
> > Chris Dowdy
> >