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Last weekend report...



Greetings,

I am finally sending a post myself! 
I had a comment and a bunch of questions that were raised after last weekend's
experimentation.

Comment:  I used Ed Phillips' method of pumping down the capacitor first
and then back filling it.  It was pretty easy to do.  I made my cap and
encased it.  Then I used a T connector with one end in the cap's fill hole,
one in the oil fill tube, and the third end attached to the vacuum pump.

I had Dave Burman and his friend Rick over on Saturday for a little coiling
fun.  We tried several configurations of my coil, which raised a few questions.
I got my power cabinet finished so I was itching to try it on my pole pig.

The first question is this:  We had an air blast gap (only) and a pole pig
for power.  As I turned up the power, I noticed that the output peaked 
before the full throttle setting.  This seems a little counter intuitive --
I thought that as I turned up the juice that the sparks would get louder,
longer, and fatter.  Instead, they actually got smaller, quieter and maybe
even thinner.  Has anyone had this happen?  I do believe that the output
voltage from the cabinet is not decreasing.  As I think about it, perhaps
the spark gap was getting overwhelmed and not quenching, but arcing more.
Any comments or suggestions?  I don't yet have the rotary gap made, so that's
why I wasn't using one.

The second question:  With the pole pig, the sparks were _much_ louder,
but not much longer (20" max).  Is the noise from the greater input power,
while the lack of length is due to the lack of adequate quenching?  Another
thing this could be is a symptom of my ground getting overwhelmed.  Currently
the ground is an 8' piece of 1" Cu pipe connected by (yes, I know) braided
strap ~1/2" wide and about 15' long.

Anyway, for a first run, without the requisite rotary gap, I was pleased
with the overall performance.  

Chip