Who needs a quenching gap ?

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

Original poster: "Finn Hammer" <f-hammer-at-post5.tele.dk> 

Gang!

Today I finally managed to get a scope trace off the new RAT-coil under
streamer loading.

This was particularly satisfying, since it confirms the Microsim based
preliminary design effort, which predicted a clean 2nd. notch quench.
This was recorded at 100BPS, about 1 meter streamer length.

http://home5.inet.tele.dk/f-hammer/ringdown.jpg

Horizontal=50µS/div
Vertical:5kV/div

Since the gap is a SRSG with onely one gap in operation, and should
therefore be a poor quencher (but possibly a "low losser") this picture
tells, that this coil is quenching the gap very well.

I believe it is possible to determine the coubling from this trace, how
is that done?

The coil is really just thrown together along the proven R.Quich
guidelines 1000 turns, 1:3 dia/length (although it is a fine spacewind
on threaded form). So the impedance match btwn streamer and coil is not
precise. Zcoil/Zstreamer= 1.6. I have tried to find a way to meet this
match, and if anyone is interested, we could talk more about this
subject. According to this work, the perfect impedance match is met,
when the toroid is arounf 10pF. I can hardly imagine that this would
make the coil perform any better than with the present 32pF . I have
never managed to create a model of a coil, that quenches at the first
notch, so perhaps 2nd. notsh quenching is natural, in some sort of way.

Comments?

Cheers, Finn Hammer