Re: first coil help

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

Original poster: "jpeakall by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jpeakall-at-mcn-dot-org>

Ryan,

While making an MMC will be cool, I don't think that the SW caps are your
main problem. I have both SW and some manufactured caps, and only find maybe
15-20% difference between the two. Even if you do achieve breakout with an
MMC, I bet that you have an inherent problem that will keep your output low.

My first suspicion is your spark gap. My smaller coil, powered by a OBIT,
7kv/23ma, breaks out fine, putting out over a foot with SW caps. I found
that my vacuum gap that I use on my bigger coil didn't work worth beans on
the smaller coil. However, a multiple washer gap with only a fan running on
it does well. In recent posts, people commented that more vacuum wasn't
necessarily better, and I found that to be true with my big coil. Reducing
the vacuum motor speed with a variac greatly helped my output. I recall you
have an air blast gap, have you tried using less air pressure? The one RQ
gap I made didn't work very well, I'm sure that's because I did something
wrong, but maybe try and whip up a multiple washer gap. Easy, cheap and fast
to make, and easy to adjust. Try 5-7 washers with .020 or so between them.
Brass washers are best if you can get 'em.

As well, sounds like your topload may be too small. I just made a 9" pie
pan/3" al duct torrid, and was really impressed with how much more output I
get.

Good luck, and keep us posted.

Jonathan Peakall


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Thursday, July 19, 2001 7:06 AM
Subject: Re: first coil help


> Original poster: "James Mathisrud by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <jrmathis-at-pressenter-dot-com>
>
>     update: well, i moved my primary up so that the first turn of the
> primary is even with the first turn
> of the secondary, i noticed that before the 3rd turn of primary was even
> with the first turn of sec. this
> helped a little. now im drawing off 4-4.5 in sparks, as opposed to 2in
> sparks, but still no breakout!
> tomorrow, i will start building an mmc cap (research and such) in hopes of
> my crap caps being the main
> problem. unless i can find someone who can measure the capacitance.
> allowing me to adjust where necessary.
> thanks to everyone
> Ryan
>
>
> >
> >
> >
> > Tesla list wrote:
> >
> > > Original poster: "James Mathisrud by way of Terry Fritz
> > <twftesla-at-qwest-dot-net>" <jrmathis-at-pressenter-dot-com>
> > >
> > > ok, well my coil is getting more powerful, but im still not getting
> > > breakout, here are my coil specs
> > >
> > > Tank circuit
> > > power    1- 15kv 30ma nst
> > > gap         1 gap 2 1.5in brass electrodes quenched with 30psi set at
3/8
> > > in wide
> > > cap         7 saltwater beer bottle caps filled with about 10 oz. ea
> > > s gap      3 1/4in carrage bolts
> > > chokes   2  2in pvc pipes wound with #28 wire about 7 in long ea.
> > > primary   16 turn helical primary 1/4 in dia. spaced 1/4 in ea. inner
> > turn 8 in
> > >                 at 45deg angle tapped at 12th turn
> > > secondary-4.5 in pvc pipe wound with #22 about 21.5 in.long roughly
800
> turns
> > > discharge terminal- tennis ball covered in Al duct tape
> > > ground 2-4foot copper clad rods
> > > im also using a 600 watt dimmer to run the transformer
> > >
> > > so far im able to draw off about 2-3 in sparks, but im not getting any
> > > breakout. im starting to think that
> > > maybe i need more nst's because my system might be too big for the one
i
> > > have also, i hope this isn't the
> > > problem, but maybe my primary it at too great of an angle. hope this
helps
> > >
> > > thanks for everyones contributions, you have all been very helpful so
far
> > > and i look forward to getting
> > > this thing working one of these days.
> > > Ryan
>
>
>
>