From: "Malcolm Watts"
Date: Mon, 30 Oct 2000 09:11:49 +1300
Subject: Re: [TSSP] NSVPI - Latter Results
Hi Paul,
> Malcolm, I don't think there's any doubt that the kind of Q
> factors that you were measuring are typical, my coil(s) too
> give a Q in the several hundreds. Terry's big LTR is unusually
> lossy but the noteable point is that it does not really hamper
> performance in the disruptive system. My guess is that if an
> identical coil but with a high Q was substituted, the performance
> would only be a few percent higher. Hopefully in the not too distant
> future we'll be able to take a close look at the coupling process in
> the time domain, and then we'll be able to say precisely how much a
> low Q impinges on system performance.
My research on primaries suggests that the performance
differences between a bad secondary and a good one can be quite
significant (remember that I said that when we quantitatively find
out). Firing seems to bear this out also. There is no doubt a bad
primary can be a real drag on performance (also shown in practice)
but if it's a good one, the secondary should also be good.
There is a way of trading one off against the other. If you
examine the beat envelope of the secondary e-field (no breakout so no
losses from that source) you will find that a good secondary will
show the linear ringdown of the primary dominating the envelope. If
you find that your envelope has a log ringdown, it means secondary
losses are dominating. It is obvious from this simple test where
improvements should be made to a given system.
Regards,
Malcolm
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.