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       #Post#: 32--------------------------------------------------
       AMATEUR RADIO Grounding theories Part-3
   DIR By: K4KGP
       Date: October 6, 2020, 12:45 pm
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       Ground Plate
       This item is controversial to some; few hams want to mount or
       put a fair sized hole in the side of
       their house. The ground plate is a solid barrier to possible
       lightning entering your house via your
       coax/cables. Also this ground plate is the fundamental item that
       creates your “single point”
       ground and gives you the proper place to install other
       protective devices, i.e. rotor cable
       protector, telephone line protector, etc. I recommend that the
       ground plate be made from 0.125"
       stainless steel. The dimensions depend on how many protectors
       will be mounted. Stainless
       steel eliminates the dissimilar metals’ concern and allows for
       direct copper attachment. If you do
       not want to actually mount the plate into the wall of the house,
       then mount the plate ON the
       house perpendicular to the wall very near to the coax ham shack
       entrance. Run the coaxes on
       one side of the plate, clear of the house entrance, then from
       the opposite side of the plate run
       the cables and internal station ground conductor into the house.
       Connect the ground plate to a
       ground pipe that is within three feet of the house. The closer
       the connection between the
       nearest ground pipe and the ground plate, the better the
       conductivity. I would use 1" or three
       5/8" copper tubing pieces between these two points and then
       reduce the copper tubing size to
       the other ground pipes. The ground plate is also used for
       mounting bulkhead surge/lightning
       protectors. The only such protection that I have used is the
       PolyPhaser brand.
       The PolyPhaser blocks and/or redirects the energy surge directly
       to your ground system. There
       are other brands of such protective devices that I haven’t used.
       This type of protective device is
       your last and perhaps best line of defense. Obviously, use of
       these devices will require that you
       install a good enough ground system to fully dissipate the
       energy. One of the biggest issues
       facing you is HOW MANY ground pipes/rods should you install?
       This is hard to determine, as it is based on soil conduction,
       how potent is the lightning strike,
       how much room do you have, and what can you afford. If you look
       at a commercial system, they
       have multiple ground radials (seven or more) each 32 feet long
       and four ground rods on each
       radial. Some of the ground rods can be sunk as deep as 40 feet.
       Well, this is not in my budget
       or in most hams! Obviously, the more ground radials and ground
       rods the better. I try to run at
       least three ground rods in a non-tower ham shack. One directly
       outside the ham shack at the
       coax cable entrance point (the shack ground), and at least two
       more ground radials with ground
       rods at their ends, separated by at least eight feet, from the
       shack ground. The tower increases
       the potential of a lightning strike, so in addition to the above
       scenario, two or more rods should
       be placed just for the tower. Put one rod near the tower base
       and the other rod eight feet away.
       Use 1" or two 5/8" pieces of copper tubing between the first
       tower rod and the tower. The goal
       of a grounding rod is to make contact with the water table.
       Falling short of that, it is to dissipate
       as much energy as possible by driving the ground rod directly
       down, attempting to traverse as
       many soil layers as possible, so energy can be dissipated into
       these various soil layers. Some
       soils conduct better than others, dry sand being the worst,
       followed by hard clay. But a hard clay
       layer may have some amount of water riding on the clay, seeking
       penetration points.
       Placing the ground rod at a 45° angle can increase the overall
       length of the radial and allow
       some energy to be dissipated. Angled ground rods are often used
       in rocky soil. The interior
       ground conductor is just as important as the exterior ground
       system. I have 5/8" copper pipe on
       the back of my bench. I use ½” tinned copper strap coming from
       each piece of equipment to the
       pipe. From the pipe, I use 1” tinned copper strap to go outdoors
       to my ground rods. All my
       equipment grounds go to a central point (pipe) and then go
       outdoors with one strap. No daisy
       4
       chaining. Most radio equipment comes with an extruding bolt,
       washers, and a wing-nut - if not
       find a good chassis screw to place the braid with washer
       beneath.
       The goal is to have an effective ground connection with short
       ground straps and to keep a clean
       unobtrusive appearance to the ham shack.
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