Re: Natural streamer :)

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

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "Steven Ward by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<srward16-at-hotmail-dot-com>
> 
> >
> >       When I run my "big" [18" sparks, but only 35 microamps short-circuit
> >current] VDG everything within several feet stars to show visible
> >discharge.  If they sharp points are close there isn't much voltage
> >rise.  If I approach it with my hand I'm liable to get zapped, but if I
> >hold a pin in my hand [pointed toward the terminal, of course] and
> >approach nothing much happens.  Same phenomenon.
> >
> >       "St. Elmo's fire" is another manifestation of the same sort of thing.
> >
> >Ed
> 
> Wait a sec!!  Your VDG can give 35uA but can only give an 18" spark??  I
> tested my VDG to have only about 7uA and can give about 22-24" sparks.  My
> sphere is a 14" oblate made from salad bowls with about 4 rolls of
> electrical tape around the rim.  Works fairly well with only a 3" wide belt.
>   I wonder why your machine has so much power but no big sparks (well big
> but not huge).
> 
> Steve Ward.

	Simple.  The column is only 18" long!  Someone gave me a piece of grey
PVC pipe and I used it as I got it.  Have been intending to extend it
for over 30 years but never worked up the ambition.  The upper terminal
is a pair of the big spun oblates which I got from Frank Lee about 40
years ago.  The belt is about 1-1/2" wide and running at high enough
speed to require lots of tension to keep it from flying off the
pulleys.  "One of these days" I intend to build a bigger one with wider
belt, but don't know where to get a decent upper terminal.

	As for the salad bowls, are you using the newer ones made of
stainless?  If so, how do you handle the rims?  I used to use the
anodized aluminum ones which were easy to cut and shape, but haven't
seen one for many years.

Ed