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RE: weird resonance with HV cap



Original poster: "Lau, Gary" <Gary.Lau@xxxxxx>

I can only suggest that the caps must have different values, or
something else in the pri/sec circuit has changed.  Ceramic caps in
particular are very temperature-dependant, though I can't believe it
would change 50%.  Your proximity to the secondary and top load will
significantly affect the frequency.

Gary Lau
MA, USA


> Original poster: Chris Estes <estescc@xxxxxxxxxxxx>
>
> So I've got a function generator and a scope and I'm trying to build
my
> primary to match my secondary. The frequency I'm shooting for (as
> measured with scope and gen on the secondary) is about 340 - 350 KHz.
> So I've got my primary lying on the ground tapped about 2 turns in,
and
> when I use a small ceramic disk capacitor of value (measured with a
> capacitance meter) 5 nanofarads I see the tank ringing at about 340
KHz
> but when I substitute my homemade cap (also measured to be about 5
> nanofarads) it rings at about 670 KHz. I measured both caps with the
> same meter so I'm thinking this must be a secondary harmonic I'm
seeing
> but I don't see the tank ring at 340 KHz when I turn the gen down like
> it should. Does anyone know whats up wit dat? Is there any reason why
I
> wouldn't see the fundamental and only the harmonics with a HV cap?
>