Re: How best to couple, was K Quiz

Subject:  Re: How best to couple, was K Quiz
  Date:   Fri, 13 Jun 1997 11:36:44 -0400 (EDT)
  From:  FutureT-at-aol-dot-com
    To:  tesla-at-pupman-dot-com

In a message dated 97-06-13 05:03:59 EDT, you write:
> I formerly used flat spiral coils. I now exclusively use cylindrical or
> solenoid wound primaries. I have not taken the time and effort to
> quantify my results but my gut feeling is that I get much better overall
> performance with the cylindrical primaries. Usually the primaries are
> about 4" to 6" larger in diameter than the secondaries and the
 >secondaries are set 2" to 4" above the top turn of the primary.
> Skip

Skip, Malcolm, All, 

The question of how best to couple the energy into the secondary is
am interesting one.  I did some work using cylindrical primaries, but
the k was really tight (but didn't measure).  Sparks flared right up the 
side of the secondary to the toroid.  I tried using polyethylene to 
stop this, but sparks still clawed their way over the poly 'til they
struck the toroid.    Seems to me that cylinder primaries would tend
to couple more evenly to the entire secondary.  flat primaries would
tend to concentrate the k at the base of the secondary.  In other tests,
I installed a piece of ferrite into the secondary of a tube TC,  I
that racing sparks would tend to occur on the secondary at the height
where the ferrite piece was positioned -- i guess the inductance was
increased at that spot causing the voltage to increase, causing
breakdown.  Seems that forcing the coupling at the very lowest
part of the base of the secondary would be best because the voltage
here will tend to be low no matter what.  But all these comments are
pure speculation on my part.  I guess some controlled experiments
should be run.  In a magnifier, maybe more "even" coupling to the 
entire secondary is better -- who knows?

John Freau