Jumping in with both feet?

From:  SBJohnston-at-aol-dot-com [SMTP:SBJohnston-at-aol-dot-com]
Sent:  Thursday, January 29, 1998 12:36 PM
To:  tesla-at-pupman-dot-com
Subject:  Re:  Jumping in with both feet?

D.C. Cox wrote:

>One problem -- you are overcoupled.  Your primary should be
> in a flat expanding spiral for the primary not 2/3 the way 
>up the sec coil.  This will also lead to flashovers from 
>primary to sec coil which may damage the magnet wire. 

The primary is not 2/3 the way up the secondary... the cold end of the
secondary sticks 2/3 of the way into the primary.   The coils are spaced at
least 5-1/2" apart all the way around, and it is the cold end of the

 I'm not sure I understand the advantage of a flat sprial primary -- can you

>You may also want to switch to a larger top electrode
>such as a 20 x 5 inch toroid for better electrostatic control
>and higher output potential.  Drive current necessary is 
>120-150 ma at 10-12 kV for this type of performance.

If I wish to add a toroidal top-load/discharge terminal i can see it will
shift the resonance of the secondary, but why will it required greater drive?

Thanks for the info!

Steve Johnston