Re: The Strangest Occurance

Hi Dan,

> > 2. Does reversing the primary leads make a difference? (Eliminates
> > capacitance between the primary and secondary if no difference?)
> --Haven't tried this one. Can you explain how this would elminate C
> between coils though?

I was unclear.  I meant to say that reversing the primary could
demonstrate, or not demonstrate, whether or not the high electric fields,
in or out of phase, between the primary and secondary, had any effect upon
the phenomena in the spark gap that you are observing.  The 20 or so kV on
the primary is minute compared to the hundreds of thousands of kV present
in the secondary electric field, so there should not be a difference if
this is what I think it is.  I think that the secondary and toroid are
acting as one plate of a capacitor. The primary is acting as the other
plate.  When you connect the base of the secondary to the primary system,
via the center electrode when the spark gap breaks down, two things may be
happening.  The base current may increase because it would not be limited
by the impedance of the ground lines (between the two capacitor plates).
The other is that this current/voltage may be biasing the spark gap
fortuitiously.  Whatever the case, you have made a very interesting
discovery.  It would be interesting to get a scope trace of the voltages
across, and the currents through, this spark gap.

I hope you have a clamp across your capacitor (resistor + spark gap), some
resistance between your transformer secondarys and the spark gap, and some
varisters between the secondarys and AC ground.  By connecting the base of
the secondary to the spark gap, your whole secondary system may have very
high voltages with respect to the AC ground of the transformer.  This can
excite high frequency oscillations in the secondarys and melt the mylar
insulation usually therein (actually the tar usually melts first and

Do you think an old RF
> choke will do the trick? 

Must be able to withstand considerable HV.  Something like 10 or 20 turns
of 40 kV wire on a 2" diameter PVC tube with some ferrite rods (or
insulated pieces of piano wire) in the center.  20 turns on a big ferrite
toroid should also work.