[TowerTalk] Measuring Ferrite
jimlux at earthlink.net
Mon Apr 14 07:40:55 EDT 2014
On 4/14/14, 4:36 AM, Ray, W4BYG wrote:
> The URL:
> 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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