Re: Primary coil form

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 7/17/01 3:45:55 PM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

> Original poster: "Vanderputten, Gary by way of Terry Fritz <twftesla-at-qwest.
> net>" <gvp-at-pvaintl-dot-com>

jGary,

I don't think the primary matters at all efficiency-wise, but a flat
primary works just as well as the others and is easy to make, and
discourages streamer strikes to the priamry, thus I like to use the
flat priamrysi.  Helical primaries can also tend to couple too 
tightly and cause flashovers, etc.   Most of the efficiency 
advanteages of today's coils are due to other reasons:

   http://hometown.aol-dot-com/futuret/page3.html

John
>  
>  For smaller coils, what is the performance difference between a
>  helical/tubular versus the 'inverted cone" primary?  
>  My past coils (40 years ago) were all helical and performance was mediocre
>  compared to what I see today. However, given my modest requirements and the
>  difficulty in creating and inverted cone, what do I give up with a helical
>  primary?
>  Is flat better than Helical?
>  
>  Specs = 
>  3.5 x 15" secondary, 900+ turns of #28 dbl 
>  12/30 nst
>  Fritz/Lau protection circuit
>  .0066 mf /30 kv cap
>  
>  Thanks
>  
>  Gary