Re: Main spark gap across one or both transformer legs?

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: John <guipenguin@xxxxxxxxx>

Never use the resonant cap size? if the resonant cap size is 
0.0088uF  then how much higher or lower capacitance should I go?    I 
was planing on doing about 0.0091 anyways

On 10/3/06, Tesla list <<mailto:tesla@xxxxxxxxxx>tesla@xxxxxxxxxx> wrote:
Original poster: Vardan 
<<mailto:vardan01@xxxxxxxxxxxxxxxxxxxxxxx>vardan01@xxxxxxxxxxxxxxxxxxxxxxx>

Hi,

At 03:35 PM 10/3/2006, you wrote:
>Hello, I have two questions. I am in the middle of gathering
>materials and designing my first coil SGTC.
>
>What is a better design....having the main spark gap across the two
>transformer's legs...and have the cap bang on 1 leg...or have the
>spark gap connect across 1 leg and have the cap bank connect across
>the 2 legs of the transformer?

"Always" put the spark gap across both legs of the transformer.  When
the spark gap shorts, it will tend to keep the high frequency stuff
out of the NST.


>Also, if I plan on using a transformer around ~9kv 30mA   is it
>completely necessary to have a full protection filter such as
><<http://www.classictesla.com/download/NST_Filter.jpg>http://www.classictesla.com/download/NST_Filter.jpg  
>http://www.classictesla.com/download/NST_Filter.jpg
>
>or can I just make two chokes, wrapping wire around an extremely
>small diameter PVC pipe along with a safety gap?

Don't bother with chokes since they are useless.  A safety gap will
be fine.  It really helps if you use an "LTR" cap size of
13.3nF.  That will give the best arcs and prevent the NST from going
over voltage.  The fancy filter is "cool", but you can live without
it if you are careful.  If you do "everything right", the safety gap
is probably not needed.  But if something messes up you need
it...  "Never use" the "resonant" cap size (8.8nF in your case).  It
has killed countless NSTs!!!!!!!!

Cheers,

         Terry



>Thanks.