[TCML] secondary variable frequency

[bartb]

Hi Scott,

Adding a toroid say just below the primary would have little effect on 
frequency, but any external object near the coil will lower the 
frequency a little (even a simple strike ring makes a minor 
contribution). Depending on geometry of toroid and coil, even raising 
the top terminal can lower the frequency. But as far as a cap between 
ground and the bottom secondary, the capacitance of the coil and the 
"new cap" would be in series. This would decrease capacitance and 
increase frequency. Now if an external cap was in parallel with the 
secondary then the frequency would lower (excluding all obvious hv issues).

Bart

Scott Bogard wrote:
> Hey all,
>      I've got a theoretical question.  Adding a top load lowers the 
> tesla coils resonant frequency, what about adding a bottom load?  Would 
> putting a toroid or some kind of capacitor between the coil and ground 
> lower the coils resonant frequency?  I think I may have touched on this 
> subject before, but for a different reason.  In any event, will a cap in 
> series with the secondary (on the grounded end) lower the coils resonant 
> frequency, and is there any way to raise it beyond what it naturally is 
> (inductor in series possibly?)  This is a theoretical question, I'm not 
> really that interested in the possible negative effects on performance 
> (although I am sure they are a consideration.)  Thanks.
>
> Scott Bogard.
>