RE: First Light- "I want bigger sparks!"

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

Original poster: "Lau, Gary by way of Terry Fritz <twftesla-at-qwest-dot-net>" <Gary.Lau-at-compaq-dot-com>

Hi Jake:

You should be able to do far better with a 15/60.  The 12" winding length of
your secondary is ultimately going to be a limiting factor, but you still
should be able to get several times your secondary length for streamers.

I've never used SW caps myself.  Many suggest that large improvements may be
had by going to MMC's.  Others suggest that SW cap losses are not so
significant.  I've found best performance with a .02uF cap.  I'm sure your
SW caps are considerably less than that.

Your gap setting sounds right, but do you have any airflow through the gaps?
In my experience, performance is dismal if I turn off airflow.

For pri-sec coupling, you really didn't address the issue.  How close is the
bottom of your secondary to the plane of your primary?  If it's too far,
coupling will be low and performance poor.  If the coupling is too close,
you'll get sparks racing on the surface of your secondary and you will have
to reduce the coupling, but it doesn't sound like that's the case.

The secondary base should not be connected to the primary, but instead,
should go to ground.  An Oudin configuration is very dangerous should you
ever come into contact with a streamer or the secondary.

The experience of most is that the larger the top load, the better
performance.  There is such thing as too large, and in this case, no
breakout occurs.  But if you're getting multiple simultaneous streamers,
then you'd get longer (but fewer) streamers with a larger top load.  My
15/60 coil uses a 7"x30" toroid.

Hope this helps, Gary Lau
MA, USA

>Original poster: "Jake Draper by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<cybermecium2-at-home-dot-com>
>
>Hello List,
>    I just finished my 3.5"X12" Tesla Coil and I am getting about 8-12"
sparks
>from it. I am pleased with the output but I think it could do better. Some
of
>you get 5' arcs and more but a 12" spark really looks great. I might just
be
>saying that because I've never seen anything better. Anyways, here are the
>specs to my coil:
> 
>   1) Transformer is a Franceformer 15/60
>   2) Capacitors are 2 wine bottles and 2 beer bottles
>   3) Spark gap is 5 gaps spaced 1/16" apart (static gap, copper tubes)
>   4) Primary is 15 turns of #8 AWG bare copper wire, tunes at about 12.75
>turns
>   5) Primary coupling to secondary is, well the secondary is connected to
the
>primary (see          Tesla vd. Oudin thread)
>    6) Secondary is 3.5" ABS wound with 27AWG Magnet wire, 12" winding
length
>    7) I have a few different toploads but the one that I get the best
results
>with is a metal bowl.
>    
>I want to know what I can do to make the sparks even longer. I think I need
>more capacitance and a bigger gap. Any information is appreciated, thanks,
>    -Jake
>    <mailto:cybermecium2-at-home-dot-com>cybermecium2-at-home-dot-com
>    http://taradev.cjb-dot-net