Re: Non-Linear Coil Winding Experiment. (and more tests!)

To: tesla-at-pupman-dot-com
Subject: Re: Non-Linear Coil Winding Experiment. (and more tests!)
From: Tesla List <mod1-at-pupman-dot-com>
Date: Thu, 16 Oct 1997 15:21:14 -0600 (MDT)
Approved: mod1-at-poodle.pupman-dot-com

---------- Forwarded message ----------
Date: Fri, 17 Oct 1997 08:31:02 +1200
From: Malcolm Watts <MALCOLM-at-directorate.wnp.ac.nz>
To: tesla-at-pupman-dot-com
Subject: Re: Non-Linear Coil Winding Experiment. (and more tests!)  

Hi Terry,

<SNIP>
> high Z source the Q (bandwidth) should broaden as you describe but Fo should
> stay the same.  Of course with non-linear coils there may be unknown factors
> at work, but my results with different resistances did not show anything
> unusual.
> 
>         Terry

Fo shouldn't stay exactly the same and measurement by myself and 
others show it doesn't. The popular 1/[2PI.SQRT(LC)] formula assumes 
zero resistance. The real formula 1/[2PI.SQRT(LC - R^2/4L^2)] takes
this resistance into account. The resistance is the Effective Series 
Resistance at the frequency being measured.

Malcolm