[RFI] Computer Speaker RFI

Jim Brown jim at audiosystemsgroup.com
Sun Mar 1 11:17:06 PST 2009

On Sun, 1 Mar 2009 10:42:44 -0800, Joe wrote:

>I only have one speaker that has RFI issues...the powered sub-woofer on my 
>downstairs home theater system.  And..only on 40 meters.  I have to turn it 
>off when I do my nets and other 40 meter activities.


There's a fair chance that a serious multi-turn ferrite choke could fix this 
problem. Something like 8 turns around a #43 or #31 toroid on each cable that 
enters the sub-woofer. AND -- if this is the type of speaker that is fed from 
the output of your power amp using speaker cable and that cable is zip cord, 
it would probably help to replace it with twisted pair. Zip cord (glorified 
or otherwise) is horrific for RFI. 


Jim Brown K9YC

More information about the RFI mailing list