Toroid Addition

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

Original poster: "Steve Steve by way of Terry Fritz <twftesla-at-qwest-dot-net>" <steve7192-at-hotmail-dot-com>

Hi again.

I would like to construct an addition to my toroid.  After finishing an MMC 
for my coil I have realized that this coil could substantially benefit from 
a bigger toroid.  Here are my current specs:

Toroid:  18" Diameter, 4.5" aluminum ducting
Secondary: 23" * 4.5"
Primary: .25" spaced ~.25" apart. ~1" from secondary.  Tapped at turn ~10.
Input: 9Kv 60mA
MMC: 0.0167 uF
SG: series of copper pipes

What I am planning is to add another aluminum duct toroid underneath the 
previous as I have seen many people on this list do (double toroid).  Is 
there any advice on the size of this toroid that people (who have experience 
with these toroids) could offer me?  I am thinking that I will probably use 
a 4" aluminum ducting at about 14" OD.

Also, if I were to add another capacitor to my MMC, thus making it 0.015uF, 
would this affect my spark lenght much?  I am simply trying to use a lower 
capacitance as to safeguard my primary transformer.

Thanks everyone!

Steve.