Re: Small VTTC's

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Dan Williams <coilerdude@xxxxxxxxx>

Thanks Shad,

You have provided the most useful info so far.
I have built a small (not micro) coil but after first
light I buttoned it up and now can't figure out why
it's not working! (Don't you hate it when that
happens!)

The coil can be seen on my site

www.coilerdude.20m.com

click on VTTC PIX and scrool to the bottom



--- Tesla list <tesla@xxxxxxxxxx> wrote:

> Original poster: Shad Henderson
> <shenderson@xxxxxxxxxxxxxxxx>
>
> Hi All,  Dan,
>
> In my experience, the "smallest" VTTC I could build
> that still produced
> a (tiny) brush discharge was a bipolar setup:
>
>
> 1" thinwall PVC wound with 36ga wire, 6" long
> Primary wound with 18ga "zip cord", ?? turns (don't
> remember)
> Tank capacitor was 2 air-variable caps in parallel.
> Not sure of the
> value, just cranked 'em to 1/2 value and removed
> primary turns to tune
> via a 'scope.
> Toploads were the 1/4" brass balls found in the lamp
> section of Home
> Depot. A wire came from each end up and towards the
> center above the
> secondary for the sparks to form.
> The tube was a 6SN7 twin triode, both sections in
> parallel.
> Power supply was a small transformer that put out
> 360V DC at maybe
> 30-40mA and provided filament power.  It was being
> abused in this role.
> Grid winding of 16-18 turns of 20ga (easier to
> handle than 36ga), grid
> leak C and R sized by trial and error.
>
> It never produced *big* sparks, only just over 1/8"
> between the two
> wires.
>
> It was *very* touchy about tuning, and didn't like
> to be "approached" by
> your hand.  Didn't light up neon or florescent well
> though.  Being a
> bipolar coil, it didn't generate lots of rf hash
> like a traditional
> single ended coil will.  Aside from being touchy
> about tuning, it was
> extremely stable, and didn't beat up the little
> transformer *too* badly.
> However it did drive the 2 dogs completely crazy
> when it was running, so
> it was probably screeching away in that audio range
> just above what
> humans can hear. :)
>
> Nice thing is that it all fit in/on one of those
> radio shack project
> boxes.  Somewhere I have a few photos of the
> lashed-up prototype before
> I got it working well.  Have to dig that up.
>
> Just my $.02
>
> Shad H.
>
>
>
> On Fri, 2007-04-13 at 16:49 -0600, Tesla list wrote:
>  > Original poster: Dan Williams
> <coilerdude@xxxxxxxxx>
>  >
>  >
>  > I'm wanting to build a miniature VTTC
>  >
>  > Thinking I will use a long pill bottle for the
>  > secondary
>  > Wondering if anyone has built a small VTTC and
> would
>  > be willing to give up some gem's of info?
>  >
>  > I am currently working on a small VTTC using a
> 3C24
>  > triode
>  > The secondary is wound on a spice container.
>  > The dimmensions are 13" high by 6X6
>  >
>  > Pictures will be on my website soon.
>  >
>  > My aim is to build the smallest VTTC still
> capable of
>  > breakout.
>  >
>  > Any pearls of wisdom greatfully appreciated!
>  >
>  >
>  >
>  >
>
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