[TenTec] Ferrite Data

[Jim Brown K9YC]

On Mon, 09 Jun 2008 17:18:42 -0600, Dr. Gerald N. Johnson wrote:

>Typical materials good up to 30 MHz in
>ferrite have a permeability of 50 though those with permeability of  125
>are good cores at 20 MHz and down, if you want reactance. If you want
>loss you want a much higher permeability.

It defies logic to speak of materials as having a single-valued 
permeability. Permeability of ferrite materials is neither a real number 
nor constant with frequency. Fair-Rite publishes graphs of the complex 
permeability, which is another way of stating the loss component. If you 
don't understand the variation of u' and u'' with frequency, you don't 
understand the material. nor do you understand how to use it. 

73,

Jim Brown K9YC