From: Paul
Date: Thu, 21 Mar 2002 19:49:53 +0000
Subject: Re: [TSSP] short H/D and stuff
Terry wrote: > http://hot-streamer.com/temp/P3200029.JPG That's looking very good. A very neat coil. Are you winding by hand or do you have a machine? > I think this arrangement will have minimal impact on the coil's > electrostatics. Might have been a little better if the taps were staggered around the circumference to reduce mutual C, but looking at the small size of these links, I don't think the difference would amount to much. Their effect, if any, will be to increase internal capacitance, which will raise still further the current peak we are looking for. Without modeling this coil in detail, we can say roughly that for h/d=1, the current maximum will be around 30% of the way in from the grounded end, and at that point the current will be roughly 20% higher than the base current (the exact values will depend a little on the coil's height above the ground plane). Therefore, if you can achieve 1% accuracy on the measurements, the results should be very clear indeed. If you can 'ping' the coil with a base voltage pulse and grab the Ibase waveform, that'll give me the mode spectrum - much better than sweeping with a sig gen! I suspect that there should be enough info in those ping waveforms for me to calculate the current profile without knowing the coil's dimensions! But I haven't worked out how to do that yet (: -- Paul Nicholson, --
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.