On 4/14/14, 4:36 AM, Ray, W4BYG wrote:
The URL:
http://home.earthlink.net/~w6rmk/ferrite.htm
States:
Identifying Mystery Ferrites
You've seen a big box of cheap ferrites at the surplus place. What kind of
ferrite are they? What's their properties? This question comes up all the
time, so here's some info on identification.
First, the statistical approach... Most all of the shielding ferrites you
see are Fair-Rite Type 43, or the equivalent. The permeability is around
1000 for lowish RF frequencies (<1MHz), and they become mostly resistive.
Measuring using an Antenna Analyzer (as long as it reads both R and X)
(Suggested by Scott Townley) Loop a single wire through the core. Run the
frequency up until R=X. The mix is identified by the following:
Mix 33 - around 10 MHz
Mix 43 - around 20-25 MHz
Mix 61 - around 50-70 MHz
Is there any consensus that this is a valid test procedure?
This is the same method suggested by Rick K.
As several have pointed out, with today's mixes, there are mixes that
might not be separable by this technique.
My advice is "try it and see"
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