Helical top loads

["Michael Deegan" <mdeegan-at-xxxxxxxxxxxx> (by way of Terry Fritz <twftesla-at-xxxxxxxxxx>)]

Hi all,

     I have been experimenting with my coil in tuning it. 6X24"
secondary, 15 turns of 1/4" Cu, a TCBOR/RQ-6, a saltwater cap, and a
12/30 NST. i made a 3.5X20.5" toroid for my coil, and the sparks cannot
break out on their own (only a groudned rod can draw the measly 1/2"
streamers i can get). Then i switched to a small foil cup in the shape
of a solid ashtray and got 4-5" streamers.

    I had about 20' left of my Cu tubing, so i bent it into a vertical
helix that slowing wound inward, kinda like an inverted cone. At the
top, i can draw 11" streamers! but i can tell theres is a lot of loss by
all of the corona off of the sides. Now, the questions...

How can I tune my coil for max. length?

Is my 3.5" X 20.5" toroid too big for my 12/30? Should i get more power?

What is the max. streamer length i can get off of a 12/30 on a 6" coil?

Thanks in advance,
Michael Deegan