I looked over those specs. I had forgotten about that earlier version of
the TT-42 coil. The specs you gave were of my old "research coil". I had
forgotten about the 6" diameter secondary and the 34 turns on the primary,
but yes that was the research coil. Then I decided to make a more
compact coil that I called the TT-42. TT stands for Table Top. This
newer coil is smaller and uses a 4.2"diameter secondary with 19" winding
length of 28awg heavy formvar magnet wire (about 1300 turns I think).
The primary is tapped at 13.5 turns, and uses 12awg solid pvc insulated
telephone ground wire (gray). This was very tricky to wind. It's a flat
pancake primary. The inner diameter of the primary winding is 6.5". It's
close wound. I use a 1.5" x 6" toroid directly above the secondary, and
a 4" x 13" toroid above that, and the 120 bps sync rotary gap. Such
rotaries have to be phased in by either rotating the motor in it's cradle,
or using an electronic phase shifter. The tank cap is 0.015uF.
Of course you can build the design that you mentioned. Either way
will work, there's a lot of flexibility for these projects. It's better to
use the larger tank cap because it keeps the voltage lower. I'm surprised
the research coil worked as well as it did considering the small cap value.
This is all I have at my website at the moment, mostly VTTC stuff.
I can't find the photos of my TT-42 coil. I'll take new photos and
put them at the website. You can find my sync gap and phase shifter
circuit at this website.
https://sites.google.com/site/jfuturet/home
John
-----Original Message-----
From: Guape Sinnelag <amn1t3@xxxxxxxxx>
To: Futuret <futuret@xxxxxxx>; Tesla Coil Mailing List <tesla@xxxxxxxxxx>
Sent: Wed, Mar 1, 2017 4:15 pm
Subject: Re: [TCML] 42" Sparks 12/30 - John Freau
http://www.pupman.com/listarchives/1999/October/msg00243.html
These are the specs I was reading. I have not actually seen any pictures
of it.
What made we look twice was the windings on primary. Sounds like I should
get some more caps and put together a synchronous gap. I bought a motor and
was getting around to making it and putting on my first coil but I saw this
and well my first coil kinda well it is what it is...
I know ive heard negative things on the black tube for secondary(abs I
think), Im going to use the green sewer line pvc. Anything consequential?
On Wed, Mar 1, 2017 at 8:17 AM, Futuret via Tesla <tesla@xxxxxxxxxx> wrote:
> I used a 120 bps synchronous rotary gap on the TT-42 Tesla coil that
> gave 42" sparks. The design won't work well with a non-synch rotary.
> My tap point is at 14.5 turns if I remember correctly, although I put on
> 21 turns of the 12awg wire. I used a 4" x 13" spun aluminum toroid.
>
>
> Of of the important things to know about tesla coils is that some things
> are important and some are not. Thickness of the wire, exact sizes,
> etc tend not to be very important as long as their within a suitable range.
> Of course the coil must be tuned properly and coupled up to the right
> degree. A TC using 0.25 copper tubing will work just as well provided
> everything is adjusted and tuned well. I just used 12awg wire to show
> that it's not all that critical, and I wanted to build something that
> looked
> rather different. My old website at AOL and then some other webhosting
> place disappeared. My transformer is a 12/30 NST, however I had
> taken it apart and removed the tar. It's a robust older model which
> tends to be a little more powerful than some newer ones. A newer
> transformer might only give a 38" spark.
>
>
> With the 120 bps sync rotary, it's necessary to use a larger tank
> capacitor. I used 0.015uF. This is important. At low bps, you
> need a large capacitor for a large bang size, for large power
> throughput. Spark length depends mostly on power throughput.
>
>
> Do you have the full specs for my TT-42 coil and a photo?
>
>
> John Freau
>
>
>
> -----Original Message-----
> From: Guape Sinnelag <amn1t3@xxxxxxxxx>
> To: Tesla Coil Mailing List <tesla@xxxxxxxxxx>
> Sent: Tue, Feb 28, 2017 11:01 pm
> Subject: [TCML] 42" Sparks 12/30 - John Freau
>
> Well maybe I'm resurrecting a dead thread, but all of this is still shiny
> and new to this future lifelong coiler(I can already tell). So I have the
> magnet wire on way, 19x 2kv .15uF corniel-dubbliers(butchered it), and will
> be testing my first rotary...
>
> Assuming I'm correct I should have .0075 uF tank. As to rotary, it is
> uncharted territory. So I might run my Flat RQ gap and my attempt at a
> rotary to see my difference. But my main thought was on the primary. So
> 34th turn(off top my head) was the tap point?
> I see a lot of intros to coils using .25" tubing .25" spacing at ~15 turns
> for primary and just tapping it till its awesome. So why such the big
> difference? I also noticed it was 12(?)g stranded wire. Does having more
> primary wraps allow better and/or more power transfer? Is there a big
> difference to the spacing between the wire?
>
> I just redid my first coil and have about 3/8 to .5 gap between turns
> instead of 1/4. It seems less feisty. I changed wiring and primary and have
> attributed my losses(incorrectly maybe) to my primary.
>
> I want to try ur primary... But what would be the difference if I used an
> avg .25x.25? On your coil specs BTW... I was using my old coil as
> reference.
> There is so much to grasp here all at once... I went from playing with
> arduinos to Tesla coils. I've learned a lot but still am one lost puppy....
> _______________________________________________
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>
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