[RFI] DSL RFI Problem Solved

Jim Brown jim at audiosystemsgroup.com
Fri Aug 20 09:47:14 PDT 2010


On Fri, 20 Aug 2010 11:33:07 -0400, Bill Gillenwater wrote:

>If your cord has 4 wires, cut out the unused B/Y. Then you can get about 40
>turns on the core. 

Thanks, Bill. This is entirely consistent with my studies of this issue -- 
it's a very high impedance common mode choke tuned to the lower HF bands, and 
virtually all successful RFI filters for telephone lines have used very high 
impedance common mode chokes. It should also work with #31.

73, Jim Brown K9YC





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