Topband: Binocular Cores

[Martin Kratoska]

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