On 8/20/2013 11:31 AM, Don Kirk wrote:
But I saw the complex impedance phenomena even with smaller diameter cores
(using different grade of material), and here is my actual FT 50-43 data as
an example.
One missing piece in understanding what you're seeing is the fact that
mu (permeability) is a complex number, u' +ju'', where u' represents the
inductive component and u'' represents the loss component for series
equivalent circuit elements. Here's a link to the Fair-Rite data sheet
for #43 material.
http://www.fair-rite.com/newfair/materials43.htm
Note that at 2 MHz, u' is about 800 and u'' is about 180. The fact that
mu is complex means that coupling between the windings will have phase
shift! Not only that, but loss in the core is coupled into the winding
as resistance, which, because it is magnetically coupled, is multiplied
by the square of the turns.
Here's a link to the listing of all their materials, with links to
corresponding data sheets for each.
http://www.fair-rite.com/newfair/materials.htm
73, Jim K9YC
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Topband Reflector
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