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Re: Nathan's Problems Continue...



Hi Nathan,

Great!  blew a neon ;-)  All great coilers blow neons when they are
frustrated!! ;-))

Actually that shows that a lot IS working.

Safety gaps should have saved the neon but if it was old it time may have
just come...

I think there are two areas that you need to pin down.

First, find where the discontinuity is in this 1000 ohms of resistance
thing.  The dryer duct on my toroids to the center post is far less than 1
ohm.  We are using "aluminum foil" duct tape and not the gray plastic
stuff.  The foil tape is usually pretty expensive.  Try household aluminum
foil wrap around the toroid if you have to get a better connection.  If you
are measuring from the toroid to another ground point so that the circuit
has to travel through the dirt, your high resistance readings may indicate
that you need another ground.

720 turns of wire on a 7 inch diameter core gives 1320 feet of #20 wire.
The resistance from the dryer duct to the base of the coil should be about
14 ohms DC.  If it is not, ohm through the joints and find the high
resistance point and run a wire or whatever it takes to fix it.

Then, tell us more about the construction of the primary cap.  How do you
know that is it 5nF (meter?)?  What type of oil, what size plates, where
did the polyethylene come from.  There are things that can go wrong there
that are not obvious (like the oil is conductive or contaminated with some
additive).  This is starting so sound a lot like there is something really
wrong with the primary cap.  I assume the wires connecting the primary
circuit are reasonably heavy and you have ohmed around in that circuit to
be sure there are no high resistance connections.  It does not take much
resistance in the primary to kill a coil's performance.  However, a bad
connection should have flamed out...

You are really getting close to the problem.  A 2 string 20 cap MMC (10nF)
would cost about $35 with Panasonic caps and that is really the worst thing
it could be at this point.

If things really get bad, we can see if there are any other coilers near
your area that could come and check it all out.  Sometime another set of
eyes that have "seen it all before" can quickly figure things like this out.

Cheers,

	Terry


At 09:40 PM 01/04/2000 -0800, you wrote:
>Hello, all
>
>It's been a bleak day in Nathan's existence...
>
>But a bit better than before, relatively speaking.
>
>I FINALLY got the sync rotary to work.  I was running the 15/60 on only 10nF 
>capacitance, and got poor output, and so I stopped.  Then I realized how 
>stupid that was. (not to stop, but to run it with that setup!)  I then put 
>one of my rebuilt 15/30s on it, and got ok output, (still only 9", but ok 
>for my coil, I guess). Gosh, I wish that would be terrible output for my 
>coil.
>
>Anyway, it ran pretty smoothly for about 10 seconds, and then blew out one 
>of my NST secondaries.  Poop.
>
>It probably served me right though, because I didn't have a protection 
>circuit on the transformer.  I intend to build one soon, but a 1kOhm 250W 
>resistor costs $15 plus 2.50 shipping from the east coast, because according 
>to Norvac Electronics in Salem OR, resistors that big don't really exist 
>over here in the pacific northwest...
>
>And, furthermore, contrary to popular belief, I wasn't running on a 
>one-poster NST before today. :) Thanks for asking, though. (It is a 
>one-poster now, however...)
>
>I don't really mean to get so cynical here, but I am getting rather 
>discouraged.
>
>I think one thing that will help is putting more turns on my secondary.  
>Performance seems to increase linearly the more turns I tap on the primary.
>
>For those of you who don't know, my present specs are: 15kV/30mA input, 10nF 
>capacitance, 15 turn primary at 35.5 degrees with the inner turn at 10.5" 
>diameter, 7" secondary with 712 turns of 20AWG wire.  Toroid is 7" drier 
>duct in a 22" dia circle covered with foil tape.  Max sparks so far are 
>about 8-9" to a grounded rod.  No air breakout yet, even with a needle stuck 
>in the toroid.  Also, I have an RQSG and an SRSG, either, or both of which I 
>can use.
>
>One possible problem is that I measure about a kilo-ohm of resistance from 
>the places on the toroid to the ground.  I have a good ground rod, and am 
>using several lengths of 3/16" copper wire to connect to it.  It's 8 feet 
>galvanized, and is connected also to a large chain link fence next door.  
>Heh heh heh!  So i think I have a good ground.
>
>What can I do, though, to get a better ground continuity to the toroid? I 
>think the problem may be in the resistance from the glue backing of the foil 
>tape.
>
>Any more help from you guys is greatly appreciated.  I am really jealous of 
>you people who run a 12/30 or 12/60 and get 25-60" of sparks!
>
>AAAAAAAAAAAARRRRRRRRRRRRRGGGGGGHHGHGHGH!
>
>Thank you all very much for your input.
>
>Best Regards,
>
>Nathan Ball
>         Tesla Coil      Grounded Rod
>               \____    /      Me
>               (____)-<|      /
>                 II    |     O -"DARN! only 9 inches!!"
>                 II    |    \|
>               __II__  |     |
>_______________|____|__|____/|_____
>You Folks
>          \
>           O    O -"This is exactly what to do to get 45" of output!"
>          \|/  \|/
>           |    |
>          / \  / \
>
>   By Nathan :)
>
>P.S. (You have all been so cheerfully helpful! What do I do next?? My 
>problems now are a bit too specific to check the archives, I think.)
>
>"I have no signature as of now."
>
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