RE: Top load smoothness matters

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

Original poster: "Mccauley, Daniel H by way of Terry Fritz <teslalist-at-qwest-dot-net>" <daniel.h.mccauley-at-lmco-dot-com>



Gary,

Yes, this is true.  This is the reason your mini-coil put out very nice
continuous streamers.  (See Terry Blakes DVD)
I used originally a John Freau toroid for my minicoil and the result was
many simultaneous shorter streamers as you mentioned with most streamers
eminating from the seam in the toroid.  However, when I switched to a
homemade shipping crate shock mount (identical to your toroid) and covered
it with aluminum foil making it at smooth as possible, i started getting
those long,
self-sustaining continous streamers that you were getting with yours.

The Captain



 > This may be old news to many, but I think it needs to be stated
 > occasionally for the benefit of those who may not have heard.
 >
 > I was attempting to better the performance of my mini coil,
 > by among other
 > things, increasing the size of the top load (toroid).  I had
 > been using,
 > with good results, a 3"x6" toroid, constructed from a very
 > smooth plastic
 > donut used for cushioning shipping skids, covered with
 > aluminum tape.  The
 > resulting surface was very smooth and may be seen at
 > http://www.laushaus-dot-com/tesla/minicoil.htm.
 >
 > I bought a length of corrugated aluminum duct and fashioned a
 > (roughly,
 > from memory) 4" x 9" toroid.  The seam where the two ends
 > were joined was
 > covered in Al tape, and a length of Al tape was applied
 > around the equator,
 > in an attempt to smooth out the ridges where breakout is most
 > likely.  But
 > the performance of the new toroid (and other changes) was
 > poor.  Was it the
 > toroid surface or the other changes?
 >
 > I went back to my original configuration with the smaller,
 > smooth toroid,
 > measured the performance, then applied a small, _slightly_
 > crumpled piece
 > of Al foil to the side of the small toroid.  The edges were
 > burnished and
 > taped flat and there were no features even close to the size of the
 > corrugated duct's ribs.  With the foil added, performance
 > plummeted.  There
 > were many simultaneous smaller streamers rather than the
 > usual few longer ones.
 >
 > At least for smaller top loads, there is no question - good
 > performance
 > requires a smooth top load.  I don't know how far this
 > conclusion may be
 > extrapolated for larger top loads, where fabricating a smooth
 > surface is
 > more costly and difficult.  I've always wondered about the
 > skeletal top
 > load construction using chicken wire or welded tubing...
 >
 > I tried using 1-2 layers of duct tape over the corrugated
 > duct to smooth
 > out the ridges, but they still were evident after Al tape was
 > applied.  Anyone know of an easy way?  I once used a wood
 > filler compound
 > to fill the ridges, which required a LOT of patience and sanding.  It
 > ultimately yielded a nice smooth surface, but it added
 > considerable weight
 > and might not survive the drop test.
 >
 > Regards, Gary Lau
 > MA, USA
 >
 >