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Re: Tuning by current mea


 MG> Ed, I don't know how many turns you have on your primary, or what your
  MG>level of pri/sec coupling is

Mark,  The primary is 14 turns.  It is wound on a plastic form at 30 degrees
(saucer shaped).  The copper tubing is on 3/4" centers.  The first turn has
1.5" clearance from the secondary.  The diameter at the top is about 28.0" if
I remember correctly.  I would think this should provide tight coupling
without overdoing it. 

MG>I attach a 100K
MG> ohm carbon resistor to the side of the toroid and then to end of the
 MG>resistor I attach a #30 wire of a length equal to the appoximate length
 MG>of the discharge, and run it out horizontally from the toroid and attach
 MG>it to a insulated support. In other words, the wire/ resistor act as the
 MG>discharge arc. Then I measure the frequency of the secondary coil with a
 MG>scope and generator. I then remove the secondary coil from the vicinity
 MG>of the primary and tune the primary circuit frequency to match that of
 MG>the secondary. It has never been off by more than about 1/4 turn on the
 MG>primary tap placement.

Mark,  Why do you remove the secondary coil in order to tune in the primary?
 It would seem that you would want it there in case it's presence affects the
frequency of the primary - and I think it would some.  

MG>By the way, I usually use a pri/sec coupling of about .15 as a starting
point.

Mark,  What is a pri/sec coupling of .15??

Ed Sonderman