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Re: TC design
> Original Poster: "Brad DiGiovine" <Guido28-at-mediaone-dot-net>
>
Hi Brad,
Comments below:
> This is my first coil, i am going to post my specs and if anyone has any
> comments on what to change let me know.
> thanks
> brad
>
> Secondary: 3"X31.25"
> i think 17awg magnet wire -at-635 turns 500 ft of wire
> primary: flat. 25 ft of .25" refigerator tubing. 5" inner diameter
> spaced at .5"
Secondary h/d ratio is way too high 10.42:1 - you need to half this ratio.
Those who have built way out in that ratio have reported poor performance.
Best ratio's seem to average about 4.5:1. I would increase the diameter to
about 4 inches and decrease the height to 20 inches. Also, the 17awg is a
bit big (it will work ok, but at the ratio I choose, you have a little over
400 turns). I would decrease the size between 20 and 24awg.
A flat primary is a good choice. 1/4" fridge tube is good as well. The 0.5"
spacing is excess and will just make your primary wider than necessary. I
would reduce to 0.375 or 0.25 inch spacing. You'll tune into about 11 turns
- but, the pie pans are not exactly toroids, so the tuning will most likely
be a bit off of that number. Top capacitance changes tuning quite a bit.
You'll need a little over 50 ft. of tubing.
Your primary to secondary spacing with 3" dia. secondary leaves you 1 inch.
May be ok, but I would recommend designing in at least 1.5 inch of space. So
add an inch to the primary inner diameter. With a 4" diam. secondary you'll
need an inner diameter of 7 inches.
> xmformer: 15kv 30ma
> caps: .007uf salt water caps
If you just want to do salt water caps for the heck of it - then cool, go
for it. But, if you want it to perform to it's potential, try MMC's or some
other cap.
> toroid: 3" flexable aluminum ducting around two inverted pie tins
> diameter of 15"
Should be ok. No big deal since you can start small and work your way up in
capacitance with almost anything. Suggest you think about spark gap type as
well. Recommend a pipe gap of some configuration with air flow. If your
going to build it, you might as well make it do the best it can.
> i appreciate any suggestions
>
> Brad
Take care,
Bart