From: Kurt Schraner
Date: Fri, 23 Feb 2001 01:29:41 +0100
Subject: Re: [TSSP] Problems with high elevation/small radius
Hi Paul, Everybody, thank you Paul, for welcoming me on this great tssp list. Paul wrote: > Perhaps Kurt and Mark can let me know if there are any lead wires > or terminals coming off the top turn? When measuring the little coil, sk5b185: bare d=0.051m h/d=8.03 sr=0.91 b/h=0.45 turns=934 f1 919.5kHz 1027.0kHz +11.7% there has indeed been a top end wire of length 27cm floating around, which surely has influenced the result strongly. Probably it was just hanging in the air, some 5...10cm distant, along the outside of the coil - I've not paid attention to it. At the top end, before pointing away from the coil, the wire forms one loose turn, with a height of the spiral of 2.2cm. Sorry for being careless about that, because I should have known better. You remember, regarding my larger long coil, Sk long: bare d=0.161m h/d=8.71 sr=0.89 b/h=0.389 turns=1976 I have written (Sun, 04 Feb 2001): "The measurements for this coil have been teaching me, how sensitive to the (-capacitive-) environment such tests behave: A 0.5m free wiping end of the winding wire, at the top of the bare coil, was showing large movements of the resonance peak weaveform-amplitude on my oscilloscope, when just pushed to vibration by hand." Soo..., what will be the least errorprone way, to perform those measurements in the future, presupposed, we want yet being able, to connect a topload to the coil, meaning wirelength=0 "not feasible"? Would a relatively short end of wire (i.e. 5cm, in the sk5b185 case), pointing radially outwards, be acceptable? I finally got all components for building Terry's low-Z amplifier, and hope to do it within the next days. This will shurely better my future results. Cheers, Kurt Schraner
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.