>Is the coax well grounded at the base of the vertical and where it
>enters the house? Is the rig/station well grounded? Are you sure
>the noise is getting in through the antenna?
This is an OLD WIVES TALE!
The earth is NOT a sump into which noise is poured! A connection to
EARTH IS NOT PART OF A CURE FOR NOISE OR RFI. Proper shielding and
termination of cable shields IS. When the old timers talked about
"grounding" things they were really talking about the use of the word
"ground" as a substitute for circuit common, NOT the earth. Cable
shields (and filter common) need to go to the shielding enclosure of
equipment. If there's no shielding enclosure, it's a bit more
complicated, but it's NOT the EARTH. In fact, a wire carrying RF noise
to earth will RADIATE that noise, just like any other antenna!
Boxes like the router in question generate trash and spew it out
dirctly due to lousy shielding and poor circuit board construction,
AND the send it out as common mode signal on all the wires that enter
and leave it. There is also some differential mode noise in close
proximity to the Ethernet cable. In my experience, the STRONGEST
component is the common mode stuff, and that's the easiest to fix.
When you do (with chokes), you'll still hear the direct stuff
radiating because of lousy shielding/construction, but it won't be as
loud. And, of course, you'll hear your neighbors' routers too.
I wish I did know of RF-quiet hardware to do these jobs. :)
Specific recommendations (and measured data) for ferrite chokes are in
my RFI tutorial. http://audiosystemsgroup.com/FRI-Ham.pdf
73,
Jim Brown K9YC
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