Re: 1/4 wave TC (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Thu, 26 Jul 2007 23:25:30 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: !/4 wave TC (fwd)

Hi Skip,

Cool! Good experiment. Sure, it will produce a spark. They all will. The 
1/4 wave assignment won't be necessary but still there's nothing wrong 
with building it. Something to consider is that every turn on the coil 
is a capacitive addition to the over all loading (turn to turn 
capacitance). It's easy to burn up the top winding without a load, so 
maybe the last few turns of your conical you can a larger wire diameter 
spaced out to prevent the close turns from a turn to turn short (imagine 
a 3 turn 1/8" bare wire) which the sparks would not hurt. It's a bit of 
a load but still part of the coil winding.

Take care,
Bart

Tesla list wrote:

>---------- Forwarded message ----------
>Date: Fri, 27 Jul 2007 10:40:33 -0400
>From: Skip Greiner <skipg@xxxxxxxxxxxxxxx>
>To: Tesla list <tesla@xxxxxxxxxx>
>Subject: Re: !/4 wave TC
>
>Bart, Dave, John, Matt et al
>
>There is some method to my "madness" that I will share with the list at 
>some point. I have been unable to find much really definitive 
>information on Tesla Coils operating without a top load so I decided to 
>generate a little bit myself. Several things have become clear, to me, 
>at least. Mainly that you can process large amounts of power with a TC 
>that is NOT terminated in a top load. Concentrating this power in a 
>single discharge is probably not trivial. It appears to me that some 
>amount of power is dissapated in a top load through radiation not 
>involved with the discharge itself. Is this radiation significant? I 
>don't know.
>
>A long time ago I saw the Corums use a wavguide that was 1/4 wave long 
>as a Tesla Coil. It worked. It had no termination and it produced a 
>discharge. Why not a TC with no top load?
>
>Anyway the next step in my experiment (for that is what this is ) is to 
>build a conical coil to try to concentrate the energy propagating
>up the coil in the top without a top load. I fully expect to see 
>discharges near the top but I am unable to predict how they will act. A 
>most interesting result so far is that nearly all of the discharge of 
>the present coil is concentrated on the very last turn at the top. Don't 
>forget that this coil is only 19" tall and right now is making 
>discharges over 12" long. The discharges go mostly upwards and most 
>interesting never downward toward the primary. Even with a toroid the 
>discharges propagate straight out.
>
>If anyone has built a conical coil, I would like to communicate with 
>you, on or off list. So far I haven't come up with a resonable way to 
>construct the secondary.
>Skip
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