[RFI] Motherboard RFI

Jim Brown jim at audiosystemsgroup.com
Sun Jan 3 21:08:00 PST 2010


On Sun, 3 Jan 2010 22:28:42 -0500, Cortland Richmond wrote:

>FWIW, I've used resonating capacitors to make SM ferrites more effective
>for a spot frequency,

That's a great approach on a circuit board where you're the designer and 
the resonance is relatively close to the ferrite alone. The techniques 
I've outlined are primarily for "after the fact" and outside the "black 
box" applications, where you're NOT the designer, and you're cleaning up 
after someone else's mess. :)

The beauty of using multiple turns to move the resonance is that you also 
get the "power of N-squared" to greatly increase the resistive choking 
impedance. 

73,

Jim K9YC




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