From: Paul
Date: Wed, 09 Oct 2002 13:01:41 +0100
Subject: [TSSP] Sonotube losses
Bare secondary: > PK FREQ kHz (Error +/-) Q FACTOR (Error +/-) LEVEL > 1 52.120 (0.01%,7Hz) 63.97 (0.25%, 0.2) -0.6dB > 2 126.034 (0.01%,16Hz) 38.96 (0.83%, 0.3) -11.4dB > 3 180.233 (0.01%,23Hz) 32.15 (2.35%, 0.8) -15.1dB > 4 229.310 (0.01%,29Hz) 29.38 (5.58%, 1.6) -18.4dB > 5 276.806 (0.01%,35Hz) 26.43 (13.28%, 3.5) -22.1dB > 6 328.292 (0.01%,41Hz) 27.83 (22.33%, 6.2) -26.5dB > Accounted for 98.85% of input signal Bare secondary with extra (dry) sonotube core: > PK FREQ kHz (Error +/-) Q FACTOR (Error +/-) LEVEL > 1 51.793 (0.02%,11Hz) 43.07 (0.99%, 0.4) -0.6dB > 2 123.593 (0.02%,25Hz) 26.43 (0.83%, 0.2) -11.6dB > 3 174.229 (0.02%,36Hz) 22.11 (2.79%, 0.6) -15.5dB > 4 220.807 (0.02%,45Hz) 21.13 (5.58%, 1.2) -18.0dB > 5 268.222 (0.02%,55Hz) 20.18 (9.39%, 1.9) -20.8dB > 6 319.881 (0.02%,66Hz) 20.69 (13.28%, 2.7) -25.2dB > Accounted for 99.26% of input signal Over 30% reduction of Q. And that's a dry tube. That surely kills off sonotube for CW secondaries. Suggests that you might exceed a toploaded Q of 80 if you replaced the sonotube. Not much gain in performance though. Notice how the resonant frequencies all fall a little. This is the 'material dielectric' effect that I'm trying to get the software to properly model. Or at least some of it is. Part of the shift might be due to the reactive effect of leakage currents induced by the coil's E-field in the sonotube. -- Paul Nicholson, --
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.