Re: Toroids

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Dave" <dgoodfellow@xxxxxxxxxxxxxx>

How do you expand a ball? I find that toroids do better at 
controlling corona at the top turns of the secondary, where balls 
need to be placed as low as possible, at the top of the secondary. A 
coil would look great with an insulator between the secondary and the 
ball, but the corona becomes unmanagable.
By the way, since Waterscapes stopped selling gazing balls at the 
nice price, I have found the best overall price and service from Amazon.com
Best price for an 8" is from artywoods on ebay. Don't look up 8" 
though, search stainless gazing, and you will see his 7.65" gazing 
ball for about $18.00

Cheers, Dave Goodfellow


----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx>
To: <tesla@xxxxxxxxxx>
Sent: Friday, March 02, 2007 12:52 AM
Subject: Re: Toroids


> Original poster: "Barton B. Anderson" <bartb@xxxxxxxxxxxxxxxx>
>
> Hi Terry,
>
> The balls have the same advantages over toroids even with a classic 
> coil. The toroid can be raised and lowered, but not expanded. The 
> balls have "that" extra dimensional option. That in itself makes it 
> a superior topload (me thinks).
>
> I will begin collecting these sphere's for toploads for my classic 
> coils. You've already figured out a nice mounting technique, so once 
> again, you did all the work and all we have to do is follow in your footsteps!
>
> Thanks for always being "cutting edge". I know there was someone 
> else who had also did the same (he's cutting edge too!). It's not a 
> knew idea as most coilers have contemplated various topload 
> configurations (sphere configurations are always part of that 
> thought process). The difference is "you did it"! And it "is cool"!
>
> I can even imagine a sphere topload like this on a super huge coil. 
> What a nice way to cut cost and enhance topload adjustment.
>
> Take care,
> Bart
>
> Tesla list wrote:
>
> > Original poster: Terrell Fritz <terrellfone@xxxxxxxxxxxxxxxxxxxxxxx>
> >
> > Hi Jim,
> >
> > PIRANHA-II can make "very good" use of an adjustable top load!  The 
> > primary is pretty well "fixed" hiding in its "bunker" and not meant 
> > to be "tuned in" ever again at that point (just like Cheney >:O))...
> >
> > http://drsstc.com/~piranha/PrettyPictures/Construction/PIRANHA-Const-012.JPG
> >
> > http://drsstc.com/~piranha/PrettyPictures/Construction/PIRANHA-total-02.JPG
> >
> > The primary coil was chopped down step by step until the right 
> > point was found:
> >
> > http://drsstc.com/~piranha/PrettyPictures/Construction/PIRANHA-Const-004.JPG
> >
> > http://drsstc.com/~piranha/PrettyPictures/BallTerminal/Tuning.JPG
> >
> > The balls just slide in and out on the brass tubing from the hobby shop:
> >
> > http://drsstc.com/~piranha/PrettyPictures/BallTerminal/TerminalTuning.JPG
> >
> > This varies the coil's secondary capacitance from 28 to 34 pF.
> >
> > http://drsstc.com/~piranha/PrettyPictures/BallTerminal/TerminalTuning.gif
> >
> > Combined with the 73.63mH secondary, I can tune from 100.6 to 110.8 
> > kHz. So if you can get the coil's tuning pretty close in the first 
> > place, no need for primary tap adjustments.  I do hold the rods in 
> > place with a bit of tape since the balls will slide right off if 
> > tipped otherwise.
> >
> > Adjustment is useful in say going from an enclosed room to outside...
> > Instead of moving the primary tap around for the best arcs, you 
> > just slide the terminal ball in and out for the best arcs...
> >
> > The ball terminal works pretty good:
> >
> > http://hot-streamer.com/temp/DaveBaehr/b01_2858.jpg
> >
> > They really are much like a conventional torroid:
> >
> > http://drsstc.com/~piranha/PrettyPictures/BallTerminal/newcoil-00.jpg
> >
> > http://drsstc.com/~piranha/PrettyPictures/BallTerminal/newcoil-01.jpg
> >
> > I really don't think I will ever plane on using anything "else" 
> > now...  In order to save lab space, I think I will just "crush and 
> > discard" my old big dryer duct toroids since this new terminal is 
> > pretty universally useful for all my coils now.  I guess I consider 
> > dryer duct and aluminum "real" toroids "obsolete" and far too expensive now...
> >
> > I do note that at lower indoor power levels, I have to use a 
> > breakout point or it just sits there and glows...
> >
> > http://drsstc.com/~piranha/PrettyPictures/BallTerminal/PIRANHA-DragonsGlowing.JPG
> >
> > The dragons and all exposed metal ,like the handles, are fully RF 
> > grounded...  Sort of a "hidden" strike ring...
> >
> > Cheers,
> >
> >         Terry
> >
> >
> > At 06:09 PM 2/28/2007, you wrote:
> >
> > > Original poster: "Jim Mora" <jmora@xxxxxxxxxxx>
> > >
> > > Hi Terry, et al,
> > >
> > > There's no rain on the parade. The PIRANHA II is a work of art as well as a
> > > technological innovation!
> > >
> > > Perhaps a better route would be to use dyer duck to bring the coil up, and
> > > as time allows build the adjustable ball top load. Do you feel it needs to
> > > be adjustable at this point? I am looking at using 6" OD Lexan or
> > > Polystyrene. Is there any value to wind to 24" and add a little more
> > > inductance to the primary?
> >
> > ........