>Subject: Re: Primary Q's and Spark Gaps
>Thanks for the note, Ed.  Have a vertical mill here and had thought
>of something like that, and glad to hear it worked for you.  I h ave
>a good supply of lucite here, so don't need a material source.  One
>question, though.  I gather you are using a flat spiral primary and
>wonder what dimensions it has vis a vis the secondary, and if you have
>an idea as to the coupling coefficient?
>Ed Phillips


My primary is saucer shaped, rising at 30 degrees.  The inside is about 8.0"
in dia. the outside at the top is 26.5" in dia.  It is 6.0" high.  I used
3/8" copper tubing spaced on 3/4" centers and have 14 turns.  The secondary
is about 30" tall with windings covering 27.6".  The primary measures 82
microheneries.  The secondary measures 32 milliheneries.

I don't have any idea about the coupling coefficient.  I originally had it
too closely coupled - which worked ok up to 1 or 2 kva.  When I started
inputting more power, I had to loosen the coupling by raising the secondary
up 3.0".

Ed Sonderman