Re: Magnifiers

Hi Antonio,

> Original Poster: "Antonio Carlos M. de Queiroz" <acmq-at-compuland-dot-com.br> 
> Malcolm Watts wrote:
> > Very simply, calculate Cself of the secondary and Cself of the extra
> > coil and add them together. That capacitance must also be added to
> > effective terminal capacitance to give the total capacitance on the
> > secondary side. Sum the two inductances, then use Ctot and the sum of
> > the inductances to determine the frequency to tune the primary to.
> This may be a reasonable approximation, but the presence of a
> significant capacitance in parallel with the secondary coil
> turns the system more complex, with three oscillatory modes
> instead of two. The expressions that I posted in the past are
> valid when the secondary capacitance is small.

I've tried it for the "cut in half" coil I mentioned and it worked 
for that without a terminal. Scope tune came in about where the 
equations suggested it should. Does one normally run with a 
significant amount of capacitance in the secondary anyway? Perhaps 
that is splitting hairs.  
    One thing I did find recently from building the scale CS machine 
was that the significant coupling between the secondary and extra 
coil affected spark performance quite noticeably (degraded it). On 
doing a frequency sweep of the system I found the Q was degraded and 
there were a few significant resonances. It's ironic to think Tesla 
may have got better performance by placing the extra coil outside the 
secondary like Golka did.

<snip - other points noted>