Locked Re: Suspect RFI into computer

Jim Brown

On 8/31/2020 9:31 AM, wojtasczyk@... wrote:
I am using an IC-706MKIIG into an antenna tuner feeding a 130 long wire antenna
I suspect a basic antenna problem, which is the lack of a dedicated return for antenna current. If we don't provide a return, Mother Nature will find her own, which may be through your ham shack and interconnected equipment to the green wire on the power line that equipment is plugged into.

Common dedicated returns for antenna current are radials or a wire counterpoise that can be in the air or laying on the ground.

In the shack, most RFI problems can be eliminate by proper bonding. N0AX has written a fine ARRL book on the topic of Grounding and Bonding, to which I contributed extensively. On my website is a pdf of slides for talks I've done at Pacificon, Visalia, and to several ham clubs. It includes a lot of conceptual drawings about how to do it right.


Yes, ferrites can help, and for HF, 4-5 turns should be wound through a #31 core or clamp-on. But don't let that prevent you from doing proper bonding, which has the more critical result of greatly reducing the likelihood that lightning would destroy your equipment! Proper bonding is pretty easy and inexpensive -- all it takes is wire and our time to do it!

73, Jim K9YC

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