[RFI] RF quiet wired routers

Jim Brown jim at audiosystemsgroup.com
Mon Dec 31 21:24:18 EST 2007

On Mon, 31 Dec 2007 19:14:30 -0600, Gene - N0DQS wrote:

>I discovered that it is a bad CAT5 cable or should I say poor, 
>cheap or something like that. Unplug that cable and the birdies 

Not a bad cable, a bad router. The cable is acting like a long wire 
antenna because the router has lousy common mode isolation on the 
output that the cable is connected to. 

The simple ferrite chokes described in my RFI tutorial will knock 
those birdies down a lot by adding a high common mode impedance in 
series with the antenna (the Ethernet cable). 



Jim Brown K9YC

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