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[TCML] Re: Why is the coil being weird???? (fwd)
yes... My bolts are rather small so I will up-grade them as soon as possible. Last night I made a 6 stage copper pipe gap that has the same amount of air blowing between the electrodes as before. I had no problems other than the sparkes were about 8" shorter than normal I tried retuning and that did not help. So I will do some more tinkering tonight and we will see. I probably just have the pipes too close together or something.
many thanks,
Jay Howson
-------------- Original message --------------
From: "Tesla list" <tesla@xxxxxxxxxx>
>
> ---------- Forwarded message ----------
> Date: Sun, 11 Nov 2007 22:06:25 -0600
> From: David Dean
> To: Tesla list
> Subject: Re: Why is the coil being weird???? (fwd)
>
> Hi Jay
>
> What kind of bolts? If they are iron or steel The thermal "resistance" as well
> as the electrical resistance will be quite a bit higher than brass/bronze or
> copper. When I first started with a polemount distribution transformer I had
> a single static gap made of brass rods 3/4 inch in diameter. It took all the
> air my shop compressor could deliver to quench, or more to the point, to blow
> out the gap. The compressor is 5HP two stage and rated 17 CFM free air and 14
> CFM at 90 PSI. The flaming arc driven out by the air blast would extend 5 or
> 6 inches above the gap. Still I had to keep run times short as the compressor
> would need to catch up after only a minute or so.
>
> Oil burner ignition transformers are usually rated something like 23 mA, so if
> yours are typical then five in parallel would be 115 mA which could deliver
> sufficient power to heat those bolts rather quickly (assuming steel) and if
> they have any markings on the heads, or if you are using the other ends where
> the threads start, the high points will keep the arc in the same place all
> the time. This can make one or more hot spots which may even become
> incandescent. Heat sinks on the outside of the tube would not help much in
> that case.
>
> Most folks using a static gap at higher power levels recommend a multi section
> gap like the RQ style which spreads the spark over several electrodes and
> offers a large surface area for heat dissipation. Copper pipe section or
> copper pipe couplings are usually the preferred material.
>
> It could be a failure in the capacitors, either shorting out or heating up and
> changing value which throws the tuning off, but my experience with homemade
> capacitors is that once they start to fail they just don't come back. I had
> some homemade rolled polyethylene and aluminum flashing under oil and they
> died hard and fast.
>
> Another possibility might be something in the primary circuit is getting hot
> and "spoiling the Q" or increasing the resistance in the circuit. Causes for
> that would be using too small gauge hookup wire, cheesy alligator clips,
> using iron wire to wind the primary, etc.
>
> The symptoms you describe however sound most like the spark gap is heating up
> and power arcing rather than quenching. Only a better gap or a significant
> reduction in power will help. You might try just one OBIT or maybe two and
> see if the coil runs better/ lasts longer.
>
> later
> deano
> On Sunday 11 November 2007 08:21:56 pm you wrote:
> > ---------- Forwarded message ----------
> > Date: Mon, 12 Nov 2007 01:58:31 +0000
> > From: jhowson4@xxxxxxxxxxx
> > To: Tesla list
> > Subject: Re: Why is the coil being weird???? (fwd)
> >
> > Currently the spark gap is 2 bolts in a tube that is connected to blowing
> > end of a shopvac. There is considerable airflow through the gap. Maybe I
> > should put heat sinks on the exterior of the tube.
> >
> > many thanks,
> > Jay Howson
> >
> >
> > -------------- Original message ----------------------
> > From: "Tesla list"
> >
> > > ---------- Forwarded message ----------
> > > Date: Thu, 08 Nov 2007 13:11:39 -0500
> > > From: futuret@xxxxxxx
> > > To: tesla@xxxxxxxxxx
> > > Subject: Re: Why is the coil being weird???? (fwd)
> > >
> > >
> > > Jay,
> > >
> > >
> > >
> > > The spark gap is mostly overheating during operation.
> > >
> > > Try letting a fan blow across the gap to keep it cool.
> > >
> > > It should help a lot.? A better spark gap may be helpful
> > >
> > > depending on the present design.
> > >
> > >
> > >
> > > John
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > -----Original Message-----
> > > From: Tesla list
> > > To: tesla@xxxxxxxxxx
> > > Sent: Thu, 8 Nov 2007 9:46 am
> > > Subject: Why is the coil being weird???? (fwd)
> > >
> > >
> > >
> > >
> > > ---------- Forwarded message ----------
> > > Date: Wed, 07 Nov 2007 21:49:41 +0000
> > > From: jhowson4@xxxxxxxxxxx
> > > To: tesla@xxxxxxxxxx
> > > Subject: Why is the coil being weird????
> > >
> > > I have been tinkering with my coil for a while now and it has been acting
> > > weird since the day I built it. but it is just starting to get on my
> > > nerves.
> > >
> > > So basically
> > > When I run my coil at first if is good. producing 30" sparks lots of
> > > noise etc.
> > >
> > > But after about 5-6 seconds it just craps out. The spark gap stops
> > > making the normal loud spark gap sounds and it starts to make a really
> > > quick softer sound. Like the one the tv makes when there is no channel
> > > and just static. At the same time the sparks length drops to about 4".
> > > I turn it off. let it chill for like 30 seconds and then it does the
> > > same thing. If I turn it off and don't let it chill it just does it
> > > quicker. Very annoying.
> > > I am currently using 5 obits in parallel and 2 .005uf home made
> > > capacitors. The spark gap is 2 bolts less than 1/4" apart in a tube that
> > > is connected to the blowing end of a vacuum. The frequency is about
> > > 600kHz.
> > > Any ideas and help will be great.
> > >
> > > Many thanks,
> > > Jay Howson
> > >
> > >
> > >
> > >
> > > ________________________________________________________________________
> > > Email and AIM finally together. You've gotta check out free AOL Mail! -
> > > http://mail.aol.com
>
>
>
>
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