[TowerTalk] Identifying ferrite core material

[Scott Townley]

If you have an antenna analyzer like the Autek VA-1 that reads R and jX, it's pretty straightforward.
Loop a single (insulated) wire through the center of the ferrite and connect it to the antenna analyzer (usually easiest to do this via a UHF panel connector).  Adjust frequency until R=X.
Mix 33~10MHz
Mix 43~20-25MHz
Mix 61~50-70MHz

or so.  More exact info can be had by inspecting charts of R and X vs. frequency from any ferrite manufacturer, since those quantities are typically measured for one turn (one wire pass through the center).  Fair-rite Corp. has very extensive technical information with their online catalog.

Of course, any other vector impedance device will work fine as well.



> 
> From: Robert Thain <g0hgw at yahoo.com>
> Date: 2003/03/14 Fri AM 09:44:08 EST
> To: towertalk at contesting.com
> Subject: [TowerTalk] Identifying ferrite core material
> 
> Hello,
> 
> I've managed to lay my hands on some ferrite cores.
> They were used to 'screen' multi-core
> computer/communication cables.
> 
> There are no markings.
> They are about an inch long, an inch in diameter and
> the hole is about 1/2 an inch diameter. (27mm*25mm,
> hole=12mm), but all of this doesn't help much in
> identifying the material.
> 
> How can I work out what they are made of and what
> their permeability is ?  
> 
> Thanks
> Robert
> g0hgw at yahoo.com
> 
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Scott Townley NX7U
Gilbert, AZ  DM43di