Re: Extra coil and corona on connection wire

Hello Don,

At 11:34 AM 9/20/1999 , you wrote:

>Hi Antonio, All,
>Yes, I did run out of primary, since 16 turns on a flat primary is all
>I had. So, to make up for it, I doubled the capacitance and was able
>to tap on turn 16, but with lots of corona power loss. 
>As many others have pointed out to me, I should be using a large
>diameter pipe, or flat wide strap for the transmission line to avoid
>the corona loss. That makes sense and is definately something
>I will try, since this was the result of some experimentation on my part
>in the first place. Obviously, I went about this bass-ackwards, but
>it's been a good learning experience.

I wouldn't get to carried away worrying about the transmission line. The
reason you had so much corona is because you were running much to high a
voltage through it. I have always just used 12-16 gauge PVC insulated wire,
for lengths up to 8 feet and 50 plus inch discharge. But when you start
running in the multi kilowatt range, it sounds as if the Al flashing idea
is great.

>It was suggested that I should be using a larger diameter secondary
>for the driver coil, possibly an 8" coil form. Any ideas how many turns
>of wire, and how much winding area on the driver coilform I should
>strive towards? My current specs are a 15/60, 6" secondary coil
>and a .01 mfd cap using the RQ static gap system.

If you do use a 8" form, then try to get enough wire on it for about ~5-7
milli Henries, using 16-18 gauge PVC insulated. You don't tune for the
secondary (driver), but for the "free resonator" (tuning for the third coil
will get you in the ball park). Use a large top load on the resonator, also
you can vary top C for fine "tuning".

>I wasn't originally aiming at a magnifier, but since it didn't take long
>to wind a second coil I might as well investigate this further. :)

It is fun to experiment ;>) Remember that, as was pointed out by John F,
you will not get longer sparks, but (IMHO) Free Resonators are quite
convenient, as you don't have to worry about primary strikes, you can place
the resonator just about anywhere you want to, etc. But some like the look
of a "classic" coil, compact and all. It is a lot more work to build a
three coil system, and for no major spark benefit, but it is always cool to
do something different.

>In some of Tesla's schematics listed in the Colo. Springs notes..he
>shows condensers connected at some possible points along the 
>secondary. I'm curious what would happen if I connected a 50kv .01
>mfd cap at the top of the free terminal on my working coil and 
>connected the other end to either a second coil, or a larger topload.
>What would most likely be the outcome? I'd rather understand the
>theory first before sacrificing a good cap. <g>

If you think about it, that 50KV cap, will not last long. The voltages (and
frequency) will make short order of it. You can try a toroid (for several
PicoF) on the top of your driver, and/or at the base of the resonator.


David Trimmell