Thank you for the thoughts! It was actually windy that night (and cold), so
perhaps I should try again on a calm night to see if that makes a
difference. My toroid is semi smooth (check out my blog showing the toroid
construction:
http://teslaplace.blogspot.com/2010/11/finally-finished-toroid.html). Also,
the racing sparks were occurring in the middle section of the secondary.
Maybe some of this extra information will spark some other thoughts. Thanks
again!
Jeremy
On Sunday, January 5, 2014, Futuret wrote:
>
> Jeremy,
>
> Yes the breakout point may have been allowing you to run with tighter
> than normal coupling. Mostly likely raising the secondary will fix
> the problem. I prefer to run without a bo point because the sparks
> generally "look" better, and can move around the toroid if the toroid
> is smooth. If there was any wind outside, that might
> have been interfering with the streamers, but I'm not sure if that
> would promote racing sparks. You could try re-tuning the primary
> too if you didn't do that. Maybe the different environment outside
> is affecting the tune-point. You may need to tune outwards a little
> with the primary tap. If the primary is tuned too much inward that
> can definitely cause racing sparks over a large portion of the
> secondary. I don't think adding a small extra toroid will help,
> but I'm not sure.
>
> Your secondary is quite large so I'm surprised you got racing sparks
> at all, of course it could be quite over-coupled. With suitable coupling,
> I don't think you'll get any racing sparks. On my TT-42 coil,
> when I installed a larger than normal 6" x 24" toroid, the sparks
> were only able to break out intermittently without a bo point, but
> there were no racing sparks even with no bo at all. Yet my coupling
> is not overly loose. I know this because it was originally too tight and
> got racing sparks even with a 4" x 13" toroid. I had to loosen the
> coupling enough to fix that. But still there were no racing sparks
> when I tried the coil with the larger 24" toroid, even when there was
> no bo at all. I was able to get longer sparks without the bo point
> using the 24" sparks, but bo was intermittent. Generally if the
> spark breaks out easily without a bo point, then the sparks
> will be no longer than with a bo point.
>
> There's also the question of where your racing sparks appear.
> If they appear near the middle or top of the secondary, this could
> be a tuning issue. But if they occur near the bottom of the
> secondary, then it's most likely a coupling issue.
>
> Sometimes spark gap quenching issues can cause racing sparks,
> but I guess it's unlikely in your case since you're using the synch
> rotary. These types of racing sparks tend to occur all over the
> secondary.
>
> Happy New Year to all,
> John
>
>
>
>
>
>
>
> -----Original Message-----
> From: Jeremy Gassmann <jeremyee78@xxxxxxxxx <javascript:;>>
> To: Tesla List <tesla@xxxxxxxxxx <javascript:;>>
> Sent: Fri, Jan 3, 2014 3:32 pm
> Subject: [TCML] Breakout point or no breakout point
>
>
> Hello everyone,
> Happy new year! To celebrate the new year this year, I gave a demo of
> my coil to some friends (and neighbors if they were watching). I was
> actually able to do it outside for the first time and tried taking off the
> breakout point since I wasn't concerned where the streamers came out. When
> I did this, however, I began getting racing sparks up the secondary. I know
> that removing the breakout point increases the top load voltage by a
> certain amount but I was surprised that it gave me the racing sparks issue
> as I thought that was related to the primary-secondary coupling. So I guess
> my question is...is it better to use a breakout point or can you typically
> get longer streamers without it since the voltage would be higher? How do I
> fix the racing sparks issue in the no breakout case? Simply raise the
> secondary some? Or would adding a smaller toroid under my main toroid but
> closer to the secondary help control the fields some? I know I would have
> to retune the primary some in this case but thought it might be worth it.
> Or would it even be better to just use the smaller top load?
>
> Here is a quick description of my coil: NST driven (15 kV, 120 mA total),
> 0.04 uF MMC, 8" x 36" secondary, large top load is 7" x 29" and smaller
> toroid is 4" x 22", spark gap is a synchronous rotary gap. If I missed any
> thing, please let me know. Thanks a lot in advance!
>
> Jeremy Gassmann
> Cincinnati, Oh
>
>
>
>
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