Hey Matthew
I have tried a variety of different taps on the primary. All the way back towards the middle to the point where I would get racing sparks. Seems the further out on the primary I tap, the better the output..... In my case it may just be all the way out at the end of the coil. I do wonder tho if I had another one or two outer turns if that would help to continue improving output trying to tap on somewhere even further than I currently have available. In my opinion, it is a decent output at the moment. When I first ran it I was getting 8"-10" arcs maybe..... I re wound the primary from a 7" inner diameter to a 5 &1/2" inner dia. and now I get about 15-16" arcs..... And they hit the strike rail!!! YES!! Haha
It may be the coupling I need to experiment with. Thanks Matthew.
Sent from my iPhone
> On Aug 31, 2016, at 7:23 PM, Matthew Sweeney <msweeney23@xxxxxxxxx> wrote:
>
> Maybe a shot in the dark, but have you tried running near the 'center' of
> the primary? I am just wondering about harmonics.. But could be out of my
> league here :)
>
>> On Aug 31, 2016 5:24 PM, "Adam Merchant" <megavolttx@xxxxxxxxx> wrote:
>>
>> Thanks to you guys that have checked out my post & photos.... Gary, Brian,
>> Matthew, and Deano. I appreciate it. Brian you are absolutely right! It's
>> very exhilarating to have success after all the planning and construction
>> of this project.
>>
>> Question- On my 15 turn primary coil, I'm tapped to the maximum of
>> the length of the coil. Would it be worth a try to remove some turns from
>> my secondary coil (de-tune?) to achieve a better output. Assuming this
>> would hopefully achieve a closer match in resonance....
>> I have shortened the secondary coil from 23" to 20" now and haven't
>> observed a noticeable difference, but it seems that most of the other
>> coilers have their primary tapped somewhere closer towards the middle. The
>> end just seems to be the best place to tap. I just don't want to keep
>> shortening my secondary if it's not changing much.
>> Thanks again!
>> - Adam
>>
>> Here is some video of some of my first runs.... Hope u enjoy
>>
>> https://youtu.be/W04DvEe8c5k
>>
>> https://youtu.be/ke4lWN4o2xY
>> Sent from my iPhone
>>
>>> On Aug 28, 2016, at 7:35 PM, Brian Hall <brianh4242@xxxxxxxxxxx> wrote:
>>>
>>> This brings up a general question I have, given what I've read here over
>> the years on this list vs. what I have learned about LC resonance in a
>> recent college circuit theory class.
>>>
>>> If the resonant frequency F = 1/(2pi(sqrt(LC))) then why does the
>> capacitance of the primary circuit need to be matched to the transformer?
>>>
>>>
>>> Or is it that the primary capacitor has two attributes: voltage and
>> capacitance. The capacitor voltage needs to handle what the transformer
>> voltage can deliver, (or 1.5 to 2x the transformer max out volts) and the
>> primary coil L and primary capacitance C need inductive and capacitivie
>> values such that F = 1/(2pi(sqrt(LC))) holds true, and match with the
>> same resonant frequency F of the secondary LC circuit? Is that all we
>> need to change when we swap out a transformer in the primary circuit, just
>> the voltage max on the capacitor?
>>>
>>> And Adam, yes I too would like to see a link to the video of your coil,
>> always fun to demonstrate your first one! So satisfying to see those
>> sparks fly.
>>> ----------------------------------
>>> Brian Hall
>>>
>>>
>>>
>>> ________________________________
>>> From: Tesla <tesla-bounces@xxxxxxxxxx> on behalf of Jonathan Peakall <
>> jpeakall@xxxxxxxxxxxx>
>>> Sent: Sunday, August 28, 2016 11:15 AM
>>> To: Tesla Coil Mailing List
>>> Subject: Re: [TCML] Show and tell first SGTC
>>>
>>> Adam, Not too surprising that you saw little improvement. The extra
>>> voltage isn't as helpful as more current would be. Try getting a match
>>> to any of the transformers you have and run them in parallel. You need
>>> to phase the outputs, plenty of info about that out there. Then of
>>> course you will need to change your tank cap value.
>>>
>>> Hope you have a safety gap set low enough that it dings your
>>> performance. And if you don't have a Terry filter I would recommend
>>> making one. NST's are pretty easy to fry.
>>>
>>> Jonathan
>>>
>>>
>>>> My name is Adam. I'm elated to be a new member. I was really captivated
>> by the Tesla Coil by the you tube community and researching Nikola Tesla
>> sparked my interest even more.
>>>> Around the beginning of 2016 I decided to try and build my own spark
>> gap tesla coil. Before summer in May; I finally had success!!
>>>> Powered by a Transco 12,000 volt 30 mA NST into a homemade terry filter
>> minus the MOVs. A tungsten rod static gap quenched with a vacuum pump and
>> ceramic magnets. A homemade MMC; one string on Cornell Dubilier 942....-K
>> connected in series. Primary coil is 1/4" soft copper tubing starting 5 &
>> 1/2" inner diameter in a conical rise of 15-20 degrees approximately....
>> 50' of copper 15 turns tapped at the very end of the inner and outer turns.
>> My secondary is a 4" PVC pipe 22" tall and the windings take 20" of the
>> pipe. I used 28 AWG magnet wire and for a toroid I used the housing out of
>> a ceiling fan which I sanded free of paint. It's about 14" in diameter and
>> about 2 & 1/2" tall. It works well, but gets a lot of streamers due to the
>> edge facing the bottom.
>>>> I've recently swapped to a 15,000 volt 30 mA NST. France brand.
>> Also added 3 more caps to my MMC for a new total of 18 in series. It has
>> improved slightly from the 12kV NST, but only slightly. I will soon have
>> another 15kV 30 mA NST; Transco brand. I anticipate a big improvement in
>> output.... Anyway, just wanted to share with the community and ask for
>> anybody willing to share thoughts/tips/advice etc... Any constructive
>> criticism is welcome and I appreciate all feedback. Trust that I will take
>> it in with an open mind. Here are some pics and video... Hope u enjoy:
>>>>
>>>>
>>>>
>>>>
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