From: "Malcolm Watts"
Date: Thu, 14 Jun 2001 10:57:03 +1200
Subject: Re: [TSSP] Progress at 12/05/01
Hi Paul, > The problem with the E-field pickup is that it collects some kind of > average reading from the whole coil, which doesn't deliver a top voltage > unless we calibrate the E-field pickup against a top volts reading from > a directly applied scope probe at small signal. The trouble is, the > calibration thus achieved, if applied to power operation, misses the > very thing we are trying to home in on - the non-linear behaviour. So > I'm hoping we can find a more direct method. Got it. You don't mention the differential probe. Problems there? > Having thought about your 17" resonator, I doubt that it would be > suitable. When the measurements disagree with the model, (as they > probably will) we would not be able to rule out the possibility that > the distortion of the coil former is responsible. I have the same > problem with my h/d=1.36 - the coils are slightly barrel shaped - I've > been using an average radius, which we get away with at f1, but it > leaves doubt about where we stand at the higher modes. > > Really I'm trying to find some h/d < 1.5 coils that can be compared with > the model on the basis of the geometry alone. Which means a coil with > a minimal former yet maintaining good shape! Well it shouldn't be hard to build something. I'll look into it. > Anyway, the 17" by 3.5' coil that you describe sounds ideal for some Q > factor and eddy coupling measurements that I can think of, so it would > be a pity to break it for that reason alone. OK - let me know what's required (exact methods etc.). Cheers, malcolm
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.