Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>
I'm pleased to report a new entry and performance record in the
mini-coil competition, using a 4kV/20mA NST. Karl Lindheimer has topped
my coil's performance by a very substantial margin, achieving a record
18.125" streamer length. See
http://www.laushaus.com/tesla/minicoilcontest for contest details.
Karl's coil details are at
http://www.laushaus.com/tesla/minicoilcontest/karllindheimer_cat1.htm.
Karl uses the same NST as I do, similar gap, and same capacitor value.
He uses an 8" spherical top load while I use a 3.5"x10.75" toroid.
Wintesla calculates that Karl's Ctop is just slightly less than mine, by
less than 1pF, so I don't know that this is significant.
Where Karl's coil departs from mine is in a much larger secondary coil -
diameter, length, aspect ratio, and inductance, and a comparably higher
inductance primary. Perhaps the "secret" to superior performance lies
in the higher primary inductance, lowering gap losses.
It's too bad that both Karl's and my experience shows that ultimately,
size matters. The 3.5"x10.75" toroid I use is aesthetically much larger
than I would like. I was hoping that the best performing mini coil
would be something I could keep on a shelf with no disassembly needed.
Congratulation Karl - and I look forward to you blowing away this record
with an SISG! Maybe there, "gap" losses will be less sensitive to
primary inductance and overall size.
Regards, Gary Lau
MA, USA