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Re: Bi Polar coil
>>From MALCOLM-at-directorate.wnp.ac.nzSun Nov 24 22:30:20 1996
>Date: Mon, 25 Nov 1996 08:53:01 +1200
>From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
>To: tesla-at-pupman-dot-com
>Subject: Re: Bi Polar coil
>
>Hello Ed, all,
>
>> You want to build the secondary to whatever dimensions you want, then
>> calculate its resonant frequency with whatever terminals you will use on the
>> ends. Then calculate the primary coil and capacitor using 1/2 of the
>> secondary frequency. It is basically two 1/4 helical resonators driven at
>> the center with no ground refrence to the secondary.
>
>This raises an interesting one that I've noticed on a one-off basis.
>One day I idly laid a resonator on its side and did the calcs on it
>using the formula I know hold good for vertical 1/4 wave secondaries.
>Imagine my surprise when I found that the thing resonated 1/2 wave
>at a higher (from memory) frequency than the formulae predicted
>(modified Cself possibly due to lying on its side). I had an untuned
>primary coupling the signal generator in to the centre of the
>structure. Perhaps something else that needs a bit more theoretical
>work. Anyone else tried this?
>
>Malcolm
>
>
Dear All, After reading all the treads on this message I thought I would
jump in since it was my coil that started Stephen asking about bi-polars.
My advise is just built it then tune it changing the cap and the coupling.
My experience with bipolars is that changing the number of turns or the
spacing is of little effect.
The bi-polar seen on the first gallery page of my website is now producing
12-14 inch arcs, and a larger version is has been built in a protoype form
producing 24 inch arcs.
I know this all sounds less than scientific but, what the heck.
Most of the construction details for it ar on the page. The URL is
http:home.earthlink-dot-net/~jimmypaul
Have fun. Jim