HE>I am interested in hearing about the best methods for grounding the ham
HE>shack, to mimimize the potential for RFI. I am looking to move to a new
HE>QTH, and build a ham shack addition to the house. Someone along time ago
HE>was talking about cutting a hole in the exterior wall, and mounting and
HE>18 inch square plate in the wall, with bulkhead connectors for the coax
HE>cables, and then grouning the equipment to this plate on one side, and
HE>then ground the plate to an earth ground on the other side. He claimed
HE>this was absoultely the best way to minimize RFI.
HE>Does this method work? Is this considered to be good approach, or what
HE>would you suggest? I really want to do this right, so I would appreciate
HE>your suggestions and feedback.
HE>Thanks. HE>Herb - KG6OK HE>herbr@netcom.com
First of all.. GROUNDING and RFI are 2 separate subjects
You GROUND electrical equipment to provide personnel safety
as required by the NEC (National Electrical Code)
you GROUND to provide lightning protection as a conducting path
to dissipate the electrical charge associated with lightning.
you GROUND to provide a counterpoise for your HF antennas.
RFI (Radio Frequency Interference) is preventing bad signals,
or signals NOT of interest from interfering with your good signals
,or signal OF interest.. You could be generating these signals
with your own equipment (computer RFI, etc), or many sources
outside of your shack could be generating RFI.
The worst case is when you dump energy onto the ground system
and it radiates into your antennas.
Poor shielding, poor electrical bonding and/or poor filtering could
degrade
your system performance.
Using a consolidated cable entry point into the shack is a good
technique.
all RF coaxial cable, all rotator control cables, telephone cables, and
electrical power cables would enter the shack at this common point.
All cables would have their shields bonded together here and have
lightning protection devices applied to all non-grounded conductors
into the shack. The earth electrode (tower ground)system would
be bonded to this cable entry point..
I use a 18" x 18"x 3/16" aluminum plate covering a "window" I had
formed in the foundation. lightning protection devices were installed
on the outside of the plate for coaxial lines and rotator control
cables.
My electrical power service panel is on the other side of the house, but
I will be sure to bond the electrical safety ground electrode to this
Aluminum entry panel.
I hope this helps..
Stan, WA1ECF Cape Cod, MA FN41sr
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