Topband: Laird ferrites

[Jim Brown]

On 6/30/2012 3:34 PM, ZR wrote:
> Evaluate against what? While Ive heard of Steward in the past I see nothing
> on Lairds site that gives me any information to base an evaluation on.

I've had samples and a catalog from Stewart for years, but there's not 
nearly enough data there on which to base a judgment.  Like Carl and 
Tom, I see no value in "much cheaper" for a product which there is only 
skeleton data, and characterizing these parts takes a LOT of time.

Every Fair-Rite suppression part has a detailed data sheet with graphs 
of impedance vs frequency, and most of them for 1-3 turns. Fair-Rite 
publishes graphs of u' and u'' vs frequency for every material.  I see 
nothing comparable in the Stewart book, nor in the Laird pdf referenced, 
and it is those data that tell a designer what they are and how they 
behave.

Jack Smith may have learned enough about the part's he using to find 
them a good option, or he may be using them in a relatively undemanding 
application, or in application where the skeleton data is enough.

73, Jim K9YC