Re: Toroids

["Tesla list" <tesla@xxxxxxxxxx>]

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?
>
> ........