Re: Primary and Secondary?????

["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 9/21/01 8:46:10 PM Eastern Daylight Time, tesla-at-pupman-dot-com 
writes:

> Hello I am Nolan I was wondering if it matters if a flat primary coil is 
> level
>  with the bottom of the secondary windings.  Maybe it would be better if the
>  bottom of the secondary windings were above the primary coil, or is it 
> better
>  to have the secondary windings below the primary?  I could use some help 
> with
>  this.  Thanks very much.
>   
>  Sincerely,
>  Nolan

Nolan,

It is not only the secondary height versus the primary that matters,
it is also the lateral distance to the side.  If for instance the lateral 
distance is great between the secondary and the primary, this will
tend to loosen the coupling.  In such a case, it may be necessary
to adjust the secondary lower to compensate.  To give an example,
I have a primary that is 9" in inside dia.  When I use this primary
with my 4.2" dia secondary, I have to set the bottom of the 
secondary below the primary.  But when I use a 6" secondary,
then I have to place the secondary above the primary.  Concepts
such as placing the secondary even with the primary, or a little
above, etc, are only a guide towards obtaining a suitable coupling.
Trial and error must be used for the final adjustment.  I usually
use a central adjustable post which permits easy adjustment of
the secondary height.

John