Hi Skip,
A capacitor like that should be useful for frequencies in the multiple 10s of MHz. If you are finding a resonance that low, there is some inductance somewhere that you are not showing us. We need to see either some schematic or a photo of cap in use where the resonance occurs. How are you measuring this resonance? Skip
http://www.future-technologies.co.uk/IMPULSE/newcoilprog/new/view2.jpg there is a large image (but without the capacitor in place here) http://www.future-technologies.co.uk/IMPULSE/newcoilprog/new/rebuild.jpgCapacitor is connected across the primary inner and primary outer connections.
Now with that variable cap installed, something is resonating at 800khz which should not be there.
With a fixed value capacitor, the problem is not there.As a small update, I also tried a series LC connection instead of parallel, and it gave the 2mhz frequency resonance and a slightly distorted wave resonance at 800khz.
Now with a fixed value capacitor across the primary, I get the 2mhz ring perfectly and this 800khz problem is not there. There is only problems when that variable cap is in situ....
The SCR connection has been also cut to rule out that now, the primary is only connected to the 1,000uF cap bank, but the entire circuit is floating, not grounded, and the other end of the primary is floating also, so only scope connections and signal generator on the primary.
I cant see how a fixed cap works fine, but the varaible one does not. It shouldn't clamp at 800khz, but it only happens with the variable cap!
Chris _______________________________________________ Tesla mailing list Tesla@xxxxxxxxxxxxxx http://www.pupman.com/mailman/listinfo/tesla