Place a couple of turns on it and measure with a handheld LCR meter. Then
use the standard formula to back into the AL value. Its not 100% but close
enough since ferrites have a wide production tolerance.
AL (Mh/1000turns) = 1000000 x L / N squared
N is the number of turns you used
The more turns used the better the accuracy of some meters especially for
powdered iron where I use 10 turns.
If you have a GDO placing a fixed cap across the coil works as long as its
within its range.
Another which can be done with a GC receiver is to place the cap in a series
trap arangement from antenna to ground and then try to find the suckout
frequency. This can get tedious.
Configure as a parallel tuned ciruit, feed with a sig gen and look at a
scope for a voltage peak.
Carl
KM1H
----- Original Message -----
From: "ZL2AAA" <zl2aaa@paradise.net.nz>
To: <amps@contesting.com>
Sent: Thursday, August 25, 2011 10:36 PM
Subject: [Amps] Ferrite toroids
> Can anyone tell me how to check the permeability of ferrite toroids.Morrie
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