Re: 1/4 wave TC (fwd)

["Tesla list" <tesla@xxxxxxxxxx>]

---------- Forwarded message ----------
Date: Fri, 27 Jul 2007 17:21:02 -0400
From: Skip Greiner <skipg@xxxxxxxxxxxxxxx>
To: Tesla list <tesla@xxxxxxxxxx>
Subject: Re: 1/4 wave TC (fwd)

Bart and all
I have built a meter that appears to work well in measuring high 
voltages. I use a 1 ma movement and a very long string of resistors in a 
voltage devider. The meter is fed through a bridge retifier. I 
calibrated the unit and it appears accurate to about 5%. When the system 
goes into resonance the voltage jumps to about 20kv with 40v input to 
the NST. I would not have believed it.

The wire in the secondary is stranded. I picked up about 100k feet of 
this stuff a while ago so I use it for everything.
Skip



Tesla list wrote:

>---------- 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:
>
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>>---------- 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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