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Re: Malcolm Watts' comments on my t.c. comments



Hi Ken,

> Original Poster: Kennan C Herrick <kcha1-at-juno-dot-com> 
> 
> Malcolm Watts' points as to Q and structural capacitance are well
> taken. The more energy going out to radiation, the lower the Q: seems
> as if that ought to be the case.  As to capacitance, perhaps t.c.-ers
> ought to contrive to wind their coils with as high a distributed
> capacitance as possible, the better to soak up energy before the big
> event.

I think one should generally aim for the lowest distributed 
capacitance in the coil with the bulk of the capacitance in the 
topload. That way, most of the energy at ringup completion resides 
in the topload with little impediment to allowing a rapid heavy 
discharge, a bit like lightning.  There appears to be a distinct 
difference in the way these two types of coils operate:

The high structural capacitance with relatively low-C topload forms 
purplish streamers easily while the relatively high Ctop type 
produces fewer of these and less easily but when fed with enough 
energy, connects to targets with a white hot discharge. This is what 
I've observed in operation.  Type 1 is great for a little tabletop toy 
coil but type 2 is serious coiling stuff.
    
I remember Richard Hull describing this sort of phenomenon with 
respect to one of his coils. He more-or-less said that up to 7kW, the 
coil in question produced a few purple streamers of several feet or 
so but on adding one more kW, "suddenly the 8-footers were there". 
Anybody else have a comment on this?

Regards,
Malcolm