In message <9d04b979323dcd428297dda95108893e0287f...@bb-corp-ex2.corp.cubic.cub>, dated Tue, 9 Jun 2009, "Price, Edward" <[email protected]> writes:
>In my example of the factor set of an H-field loop antenna, which I >used because the amplitude might go from 28 dB @ 300 kHz to 88 dB @ 20 >Hz (data from my EMCO 7604 passive loop), I would expect the >lower-frequency end of the plot to be linear. Yet, when I lay a >straight-edge to the actual plot, I find a few slights humps and bumps. If that's purely a passive loop, its response is calculable, and any humps and bumps must be due to measurement artefacts. However, that would give an antenna factor of 28 dB at 200 kHz, not 300 kHz. Do you know the inductance of the loop? Do any active loop antennas feed the actual loop into a zero-impedance load, thus producing a response independent of frequency? > >Are these deviations attributable to my cal lab's equipment errors or >setup errors? Is my straight-edge warped? Or could these deviations be >real? While watching for the signs of measurement overloads or >noise-floor limitations, I also have to admit that maybe there is >something in my probe which creates tiny resonances or coupling effects >that really does affect the theoretical results. You aren't going to get any resonances due to micro-mechanical structures in the 20 Hz to 300 kHz range. -- OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk Things can always get better. But that's not the only option. John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
