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Re: Flat coils & undamped waves (was Wire Length)



Original poster: Ed Phillips <evp@xxxxxxxxxxx>

Maybe I'm splitting hairs, but I have to disagree about the last sentence, of Wheeler formula application for ribbon wire flat spirals. Please see my 2004 TCML posting:

http://www.pupman.com/listarchives/2004/October/msg00018.html

especially the 2 graphs:
http://home.tiscalinet.ch/m.schraner/Lstrip_Wheeler.gif
http://home.tiscalinet.ch/m.schraner/Lstrip_NBS.gif

To use the right calculation method can be crucial, when designing a ribbon type flat spiral primary: the too high L prediction of Wheeler may lead to a too small primary construction.

Kurt"

Wheeler's APPROXIMATIONS were presented as exactly that, with explicit limits on parameters and the associated accuracy. This last part sometimes gets forgotten, leading to erroneous results. The correct Wheeler formula applied with the correct dimensional limits gives good accuracy.

Ed