help with bipolar design

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Original poster: tesla-at-blankadventure-dot-com 


Hello, I don't post much but I've been a long time lurker and have built 
several coils in the past.  For my next project I'm looking to build a 
bipolar coil, mainly because I like the antique look.  It will NOT be 
center grounded; ie, it will just be one continuous coil of wire.

Here the specs I have to work with:
- 12/30 or 12/60 NST
- 28 AWG wire
- two spun aluminium toroids, 14" total diameter, 7" diameter of the hole
- static spark gap
- LTR MMC

so this is what I have to design my coil for.  For my secondary I want to 
use the Jean Freau approach (so more secondary turns)...I figure 35" 
winding length.  That'll give me a 10:1 ratio, which is double the standard 
5:1 ratio, which I understand is what you want for bipolars.  This will 
result in approx. 2552 turns.  How does this all sound?

For the primary which will be solenoid in shape, I figure a diameter of 14" 
should work.  This would give a 3.5" clearance from the secondary form.  Is 
this too much/too little?  Also, I have no idea on the number of turns or 
spacing....please advise!