Re: Primary Q's and Spark Gaps

Hi all,
        Written was.....
>     Just getting back to a topic which bugs me a bit: based on some 
> comments by Mark B., I was rather suprised that people are only getting (and 
> correct me if this is wrong) primary Q's of maybe 10-20 with no 
> coupling to the secondary circuit.
>     Throwing some numbers at it, let's assume the primary 
> inductances people might use are, say, Lp=100uH and the primary 
> capacitance, Cp, might be 20nF. Estimating Qp=sqrt(Lp/Cp)/Rp, the 
> "average" primary resistance from all factors such as spark gaps, 
> skin, proximity, adn dielectric losses should be about Rp=0.3ohm. 
> Seem reasonable? 
O.K., here are some real figures based on measurement of my coil.
Stats : Lp = 11.8uH (including a couple of feet of stray wiring)
        Cp = 102nF  (extended foil)
        Static Gap firing voltage = 7.5kV
Measured Q (using sig gen and scope - i.e. no spark gap) about 50
        => Rp about 0.22 Ohms
Measured Q (operational using ping test and decrement calc.) =11.5  
        => Rtot = 0.95 Ohms
        => Rgap about 0.73 Ohms!! (accounts for 3/4 of all losses)