TSSP: List Archives

From: Paul
Date: Fri, 01 Mar 2002 09:50:12 +0000
Subject: Re: [TSSP] Ion Cloud Loading

Further to this,

It occured to me that it might be better/safer to drive the
coil from the TCT via a few well insulated primary turns,
otherwise fine tuning could be nerve racking.

Terry wrote:
> I found no evidence that the coil's DC potential had any
> affect on the system's resonant frequency

Oh, I see now.  If fres varied, then you'd expect a lower
amplitude. 

> The "Q" of the coil setup was about 15.8 (253/16)

So not a very sensitive test, I think.  How about repeating
it with TCT into primary, freq counter, and a much smaller
topload (so that the 'ion C' has a greater relative effect).

Greg wrote:
> I suspect that it's the additional capacitance of the streamer
> channels themselves which are actually responsible for any
> measured tuning shifts.

And I'm guessing that Bert would concur.  The streamer channels,
rather than a cloud of ionised gas molecules, would be the
major source of an 'upheld' charge.

Oh, and while we're putting kV of DC into the coil base, would
this give a nice and accurate method for estimating the total Cdc
of the secondary?  Charge to a few kV, disconnect the Bertan, and
then time the voltage decay as it leaks back to ground via a 
known shunt resistance?
--
Paul Nicholson,
--


Maintainer Paul Nicholson, paul@abelian.demon.co.uk.