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RE: First light, and a poor performance

Forgive me, but something is just not right here. A 4" coil at 4KW should
do *MUCH* better than 27"
I belive Mike Hammer has gotten better than 50" with about 1KW, and I
personally have manged to get
37" from 720VA on my 6" coil. I suggest taking a good look at your ground -
and your caps.
You may want to check into a solid topload too.


Michael Baumann - Homebrewer, Coiler, and Ghod knows what else....
mycroft-at-access1-dot-net

-----Original Message-----
From:	Tesla List [SMTP:tesla-at-pupman-dot-com]
Sent:	Sunday, August 30, 1998 4:31 PM
To:	tesla-at-pupman-dot-com
Subject:	Re: First light, and a poor performance

Original Poster: Steve Rodway <Legion-at-legion-elec.demon.co.uk> 

As a result of some experimenting that Michael Tucknott and I have done
today, we were able to improve the output of my 4"x16" coil from 11" to
over 27".
The Primary was re-wound replacing the 1mm wire with 6mm copper pipe, this had
minimal effect and the slight improvement was due almost entirely to the
reduced
coupling that the new primary provided.
    The secondary was raised from it's initial position level with the bas of
the primary to 1.5" about it giving about a 10% improvement.
    The existing 3x1mm tungsten carbide gaps were replaced with a terry fritz
style gap consisting of 7x0.5mm. This was the maximum gap spacing at which
firing was reliable as I am not employing resonant charging. The TF gap
performed EXCELLENTLY and was able to quench well even at 4Kw of input
power but
was unable to quench at 5Kw. It's performance was degraded slightly if
there was
no air flow, but was still good. This new gap was the primary source of the
improvement in performance, and many thanks to mike for letting me use it!
    The topload was made of a finite element array toroid 3"x14", our tests
indicates that a finite element array topload makes for a very impressive
looking coil as there are typically 3-8 arcs at any time, also the array can
produce a faint and very uniform corona extending 12" in all directions
when run
just below breakout. On the down side, element arrays seem less suited to
producing maximum arc length as it is virtually impossible to prevent multiple
breakouts, so the energy is spilt between several streamers. The toroid was
also
to small, in order to achieve maximum arc length, a 5"x10" (about) duct toroid
was placed on top, I plan to make a larger array soon to try to get max
performance from just an array topload.
    Tuning was found to be very critical, moving the connection point by 1"
made
a noticeable difference in output.
    Mike and I have come to the conclusion the we have removed virtually all
major problems with the system, so the high power levels required to produce
good output are, we feel, due to losses in the ceramic caps I am using.
    For the future, I plan to re-wire the bottom end electronics, replacing
the
1mm wire with 2mm or larger in order to reduce what small losses may be
present
there. I am going to try to build some salt water cap in order to check the
theory about high losses in the ceramic caps.   When I am happy that the
coil is
performing as well as it is going to, I want to construct a 6"x20" coil.
    Thanks to everyone on the list for the help and advice which has
enabled me
to get this thing running OK, especially mike for the help today.

--
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