Bipolar primary design

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: <tesla@xxxxxxxxxxxxxxxxxx>


(I've posted about my bipolar coil plans once or twice on this list 
but I never seem to get the time to actuall start building the thing!)

I'm working on building a bipolar coil (the 1/2 wave, horizontal 
variety - NOT a twin). The secondary winding length is 3.25" x 32", 
wound with #28 wire, capped with a 3" x 14" toroid on either end. 
I'll be powering it from a 12/60 NST, with an MMC bank of 0.014 uF 
(this is right on resonance; I'm not worried about killing my NST as 
I have many of them).  For the primary coil, I will be using a 
helical coil wound from 0.25" copper tubing, spaced at 0.20" per turn 
with a diameter of 9.75" (ie, 3 x the diameter of the secondary)

My understanding is that to analyse the properties of such a bipolar 
coil, I just need to "cut it in half" and analyse it as per a regular 
coil. In that case, I have a 3.25" x 16" secondary with a single 
toroid. Putting these values into WinTesla gives me a secondary freq. 
of 225 kHz, and indicates I'll need approx. 12 turns on my primary 
coil for tuning.....

ok, haha, all of that leads me into my one simple question....since 
I've cut everything "in half", does that include this primary? Do I 
need to double my primary, ie, use 24 turns for my REAL coil?

Thanks, all mighty TC list

-Patrick