Re: Max spark length

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

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 9/18/01 9:13:18 AM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

> With a 15/30 NST and a 4.5 inch (dia.), 20.25 inch (height) secondary, what
>  is the max spark length I can get at resonate frequency. My toroid is 26
>  inches in total dia. and 6 inches in tube dia.

If everything is just right, you may get 40" sparks if you don't
use a 0 - 140V step up type variac to power the coil.  If you
do use a step up type variac, then you could get longer sparks.
Much will depend on the type of spark gap, the quality and size
of the capacitor, etc.  The toroid is a little
large for such a coil, it won't make the sparks shorter, but it
won't make them longer either, than a smaller toroid of 5" x 20"
corregated or 4" x 15" smooth.  Often folks get only 20" to 24"
sparks from such a coil due to design compromises.

John