Re: 1/4 wave TC (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Thu, 26 Jul 2007 18:04:19 -0700
From: Barton B. Anderson <bartb@xxxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: 1/4 wave TC (fwd)

Hi Skip,

Thanks for the specs. I know only 50AC input to the NST is where the 
arcing is occurring, but when your running in resonant mode, those 
voltages can really sky rocket pretty high. You may have difficulty 
measuring the resonant output voltage and if high enough, may damage 
your probe (don't lose a useful toy from assuming the probe is capable). 
An easy method that is safe is to double up your capacitance and watch 
for a change in the gap arcing with input voltage measurement. Of 
course, that assumes you have the caps available to try it.

To get the coil to arc at L2's wire length calculation, you can't load 
the coil with a top load. So, I understand what your trying to do. But 
you'll obviously need some means of an output terminal. This will be 
difficult if your trying to create long sparks as you will get early low 
voltage breakout. In any event, it's fun to play with different systems 
to see what they can and cannot do.

BTW, is this wire by any chance stranded 22 awg?

Take care,
Bart

Tesla list wrote:

>---------- Forwarded message ----------
>Date: Thu, 26 Jul 2007 11:15:53 -0400
>From: Skip Greiner <skipg@xxxxxxxxxxxxxxx>
>To: Tesla list <tesla@xxxxxxxxxx>
>Subject: Re: 1/4 wave TC
>
>Hi Bart and All
>
>Sorry for the confusion in the specs. The primary is 19 inches in 
>diameter wound with 0.25" copper tubing with 0.25" spacing between 
>turns. The secondary is 14 inches in diameter. Both windings are 
>helical. The bottom turn of the secondary is in the same plain as the 
>top turn of the primary. This positioning of the secondary was necessary 
>to reduce the coupling between primary and secondary. Unpowered, the 
>resonant frequency of the secondary with no top load is about the same 
>as the 1/4 wave frequency of the wire length in the secondary.
>
>All of the arcing that is taking place is with only 50vac input to the 
>NST. I will try to measure the NST output voltage when powering the coil 
>and try to verify that resonance is indeed causing the arcing that is 
>taking place.
>
>My intention with this coil was to build a secondary that would resonate 
>at the at the 1/4 wave frequency of the wire length used in the 
>secondary. Indeed, with no top load, the overall excited resonant 
>frequency of the secondary is only slightly below the non powered 
>resonant frequency. Although the sparks without a toroid are only about 
>12" in length, there are a huge number of them and I plan to try to find 
>a way to concentrate them without a toroid. Also I will be increasing 
>the cap size to see the effect on the NST resonance problem (?).
>Skip
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