Re: Fanciful spark-augmenter

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "Kennan C Herrick by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <kcha1-at-juno-dot-com>
> 
> In my interchange with Scott Fulks yesterday on the subject, there
> remained a question about the Q of my fanciful apparatus.  I made a quick
> measurement today:
> 
> I wound 5T of 12 ga house-wire around a 12" dia form, connected a fixed
> capacitor across it, excited it with a 1T loosely-coupled coil from a
> signal generator, and measured its Q using the Fr/(F(hi)-F(lo)) formula.
> With a .03 uF capacitor the Q was ~18 and with a .07 uF one, 16:
> essentially the same.
> 
> Not too near the Q of a good secondary, to be sure, but maybe good
> enough.  If excited with--say--my primary where I develop perhaps 300
> volts/turn of equivalent conductor, I should think I could pump up such a
> resonant tank to perhaps 3000 volts/turn.  At 5 turns, I would get 15 KV.
>  That's a fairly respectable capacitor-charge that subsequently might be
> dumped into the secondary at the slightly-shifted Fr.
> 
> Ken Herrick

	Something sounds very wrong with those measurements.  Can't imagine
such a low Q unless there was something wrong with the capacitors.   You
didn't give the length of the primary, but assuming it was of the order
of an inch or so the inductance should be of the order of 12 uH.  That
would give a resonant frequency around 264 kHz for the 0.03 ufd
capacitor and 174 kHz for the 0.07; what did you get?.  I'd expect a Q
of well over a hundred in both cases.  Instead of coupling through the
second coil, why don't you try connecting the signal generator to the
primary/capacitor in parallel through perhaps a 10 k resistor and repeat
the measurement?

Ed