Re: New Coil

To: Tesla List <tesla-at-poodle.pupman-dot-com>
Subject: Re: New Coil
From: Chip Atkinson <chip-at-poodle.pupman-dot-com>
Date: Sat, 24 Aug 1996 22:16:57 -0600 (MDT)

>>>
We tried using a multiple spark gap made from 5 1" pieces of copper 
pipe.  Spark length 
went from 2'+ to a max 
of about 6".  Is this because it is not quenched?  Any ideas would be 
appreciated.

Thanks
Dave
<<<

Dave,

Was that the pipe gap that I lent you?  If so, I'm surprised.  I know 
that when the gap heats up, the coil grinds to a halt, but until then, 
it works pretty well (or it has for me anyway).

If you mean 1" long pieces, it may be that there is not enough surface 
area to quench the spark.  I believe that the air between the pieces 
can't get too hot or it will remain ionized/conductive and performance 
will be severely affected.  

Two other things to consider:  The gaps must be parallel so that the 
spark isn't forced to the closest part.  A pipe gap with the pipes like 
/\ (exaggerated) will only spark in one place.  This type of sparking 
will cause localized heating.
The gaps should be fairly clean and smooth.  A burr, or a clean spot on a 
dirty section, will cause the same sort of problems as non-parallel pipes.

Finally, check the spacing between the pipes.  I have had good luck with 
0.030".  I use an automotive feeler gauge to set the gap.

Chip