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Re: Topband: Binocular Cores

To: topband@contesting.com
Subject: Re: Topband: Binocular Cores
From: Martin Kratoska <marcom@centrum.cz>
Reply-to: marcom@centrum.cz
Date: Mon, 08 Jun 2015 09:22:45 +0200
List-post: <topband@contesting.com">mailto:topband@contesting.com>
Is somewhere available a list of ferrite mixes indicating the frequency where R=X?

73,
Martin, OK1RR

Dne 1.6.2015 v 17:31 Tom W8JI napsal(a):
You really need to do a single loop through the core windows and measure
the impedance with some sort of analyzer. Even an MFJ259B with a short
connection to the jack will work well for this.

If the resistance equals the reactance down somewhere around 2 MHz, it
is 73 material.

If R=X someplace much higher, you can be sure it is a different mix. The
Q=1 frequency, where R=X or where loss tangent crosses reactance, tells
you the material better than anything else you can do.

That is how I quickly sort unknown cores.

73 Tom

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