On Wed,10/5/2016 8:58 AM, Huff David J wrote:
I am helping a friend setup a station, and I have 2 basic questions on bonding
and grounding.
1. We have some GFCI outlets that were showing RF issues, so I added
ferrites around the 120Vac wires leading into the GFCI to solve the problem,
but someone asked if that violates NEC code. I am unable to find anything for
or against this in NEC, but I am not an expert. Does anybody know if this is
acceptable? Do I need any specific mounting, banding, or grounding to meet NEC
code with ferrites.
It is acceptable. But better to replace the GFCI with one that does not
have RFI issues.
2. There are multiple HF radios next to each other, and someone had the
bright idea of running a single ground wire around the shack, then tied to a
single ground rod. I found during testing that a single ground wire acted like
an antenna, causing lots of interstation interference. Adding ferrites to a
ground wire seems to work, but causes some people to question if this is
acceptable.
It is not.
I realize lightning and high voltage will blow right past the ferrites, but
is it acceptable to add a ferrite to prevent interstation interference? I
personally think the people driving this do not understand the concept of
grounds, but that is another whole topic.
You are correct.
Study http://k9yc.com/GroundingAndAudio.pdf
What are your antennas? I would suspect problems there. If, for
example, you have an end fed antenna that ends in the shack, it needs a
counterpoise. If it does not, return current from that antenna will flow
in whatever return path is provided, including the green wire in your
home, that ground wire, and all the wiring in the shack.
73, Jim K9YC
Thanks,
David J. Huff
W0im
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