Re: Sword-like VTTC spark pix at my website

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Original poster: "brian by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ka1bbg1-at-mcttelecom-dot-com>

Hi, the only advice for ceramic tubes -vrs- glass is 2 things: 1 use the
correct tube base with cooling,2 start out at low power until you are sure
there are no parasitics and tuned up. ceramic are hi-power for their size
but without good tuning and the right amount of air cooling they go PUFF
real easy. cul brian
----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Friday, February 09, 2001 9:20 AM
Subject: Re: Sword-like VTTC spark pix at my website


> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<cwillis-at-guilford.edu>
>
>
> Nice photos John!
>
> I'm glad to have seen this really unusual spark in your pictures- I never
> quite knew what you meant before.  My coil does not exhibit this
> phenomenon, but I use a horizontal breakout and a larger topload.   With
> smaller CW coils, I can get a single vertical strand of arc into air (the
> 811-a coil schematic at www.angelfire-dot-com/electronic/cwillis/811acoil.html
> will do this) but the appearance is not the same.  I think that by using
> vertical breakout, heated / ionized air rising through the electric field
> can strongly contribute to discharge shape and length, maybe forming a
> bubble or column of warm, rather conducting gas over the topload for the
> next spark to "aim into."    I'll have to make some adjustments and see if
> I can reproduce the effect on the staccato 833-A coil.
>
> One interesting effect I do see on the 833-A coil are sparks that have
> "knots" or beads in them, in some cases the beads seem to be actual
> looping-back of the discharge around a 0.25" radius or so.
>
> On the subject of tube coils, I feel the irrepressible urge to build
> another 'un soon- for some reason, classwork just doesn't provide many
> thrills in life. So I'm planning to go with a push-pull oscillator, with
> 4CX300's or similar (if I can afford them) or some "no-name" tubes from a
> diathermy machine I recently sacked.  My goal is to make a "half-wave"
> coil, with two secondaries base-fed off coils tightly coupled to the tank
> inductor.  MMC capacitor.   I'd like to include a "super staccato" cathode
> grounder and the good old level-shifted supply.  If you (or any of the
> other tube coilers) have tried "half-wave" tube coils I'd be interested to
> know.  Also, if you have advice regarding using the ceramic tubes I could
> use it- I have always stuck with glass before.
>
> Thanks for posting those pictures- they have certainly made a worthy
> conversation piece!
>
> -Carl Willis
>
>
>