From: Paul
Date: Mon, 08 Jul 2002 23:21:57 +0100
Subject: Re: (Fwd) Re: [TSSP] Experiment 7
Hi Malcolm, All, > Was ground resistance been checked as readings were taken? No. I wonder if those small rapid q variations seen when outdoors would correlate with ground resistance? I guess that's just one of loads of experiments suggested by those results. It's hard to know where to start really. > The variations are huge compared with what I saw in an air- > conditioned environment... I'd like to look at a coil installed in a faraday cage to isolate it as far as possible from the wider environment. That would be at the other extreme compared to the first experiments. The most important thing for me to come out of this is that I no longer worry too much about not being able to calculate the coil's Q factor. Having seen that there are so many other factors involved apart from just the coil's intrinsic loss, it seems less important to try to calculate this. > Thanks Paul and Terry for all the work you've put into this: No problem - we're just picking up the good work you started back in 1995. And this ringdown stuff also ties up nicely with what John Couture on pupman is trying to achieve with lamp tests, if we can just steer things onto firmer ground. We seem to have two major irons in the fire at the moment - things depending on ping analysis, and things depending on topvolts measurement. The former seems to be the more mature technology right now, and offers the immediate possibility of some rewarding experiments. For example, I see some questions raised on pupman about dielectric losses, and we can use a test coil, pinger, and tcma to test tube samples inside a coil. The professionals seem to do this kind of stuff too, for example http://lemp.snu.ac.kr/work/dielectric.html We can also look at primary losses, gap and proximity. Gary sets a good example with his http://www.laushaus.com/tesla/primary_resistance.htm Work like that is the bedrock on which solid progress is made. And talking of the profs, Charles Sullivan has another paper out, investigating the use of 60-100kHz HV coupled to power lines to de-ice them, http://thayer.dartmouth.edu/other/inductor/hfdeice.pdf Now there's an interesting applet for a CW TC in the megawatt range. I never realised ice was so absorbent at these frequencies. We saw some pretty wild Q behaviour towards the end of expt2 when everything iced up. I won't bother to try the ice dielectric caps for my coil then. Cheers All, -- Paul Nicholson, --
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.