Re: pri-sec elevation (was Magnet Wire Sources)

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

Original poster: Edward Wingate <ewing7-at-rochester.rr-dot-com> 

Tesla list wrote:
 >
 > Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
 >
 > I have not assembled a "twin coil" setup so I can not advise on this
 > question.  Perhaps Ed Wingate could advise you --- he has a large twin coil
 > setup that performs very well.  I think it is a magnifier design.
 >
 > Dr. Resonance

DC, Steve,

My twin isn't a magnifier design. I briefly experimented with a large
twin magnifier but put it aside due to time and logistics constraints.

The distance between the inside of the primary and the bottom turn of
the secondary is 2 inches and the primary and bottom turn of the
secondary (20" diameter) are at the same level. This level was
determined by experimentation to be the optimum height for best
performance. Your mileage may vary. I always deliberately build my coils
to be overcoupled and then gradually raise the secondary with spacers
until the telltale signs of overcoupling, secondary interturn arcing and
primary/ secondary arcover, stop. Every coil is different and IMHO this
is the only way to find the optimum coupling.

HTH,

Ed Wingate RATCB

 >  > What would you advise for a twin TC setup?  Of course the composite
 > primary
 >  > is divided into two separate primaries, each about half the normal 
primary
 >  > inductance.  That being the case, it seems like the optimum elevation of
 > the
 >  > two secondaries will be less than for a single primary-secondary coil of
 >  > equivalent size.  Any practical experience-based comments?
 >  >
 >  > Thanks,
 >  > Steve Young
 >  >
 >  > ----- Original Message -----
 >  > From: "Tesla list" <tesla-at-pupman-dot-com>
 >  > To: <tesla-at-pupman-dot-com>
 >  > Sent: Sunday, May 30, 2004 10:05 AM
 >  > Subject: Re: Magnet Wire Sources
 >  >
 >  >
 >  >  > Original poster: "Dr. Resonance" <resonance-at-jvlnet-dot-com>
 >  >
 >  >  ><SNIP>
 >  >  > We make a lot of 18 inch dia. coils and found 7 inches to be the most
 >  >  > effective coeff. of coupling.  For our 24 inch dia. coils it 
requires 9
 >  >  > inches for best performance.
 >  >  >
 >  >  > Most experimenters way over-couple their coils and lose performance
 > that
 >  >  > they are not even aware is available.
 >  >  >
 >  >  > Happy coiling,
 >  >  >
 >  >  > Dr. Resonance
 >  >
 >  >
 >  >