Run 4" PVC conduit anywhere you might want to make an antenna coax run.
Include drains for the underground run and ends with gentle U bends to
keep rain out. Use conduit sweeps, not plumbing elbows for the corners.
Coax doesn't do well with sharp bends. Install a run of nylon rope with
a loop at the middle and twice as long as the conduit run for
convenience in pulling cables in the conduit. Run a separate conduit for
the 120 volt outlet at the tower.
You can't have too many grounds. Space rods a rod length to get the
maximum benefit. Connect the RF grounds with wide straps, not copper
wire for the best effect. Grounds under a building have a chance of not
staying wet, if the ground water the rods reach is dependent on rain
water and not on ground water. Lightning currents through ground wires
and rods passing through concrete have been know to destroy the concrete
which can be a hazard from flying concrete, and can weaken the structure
dependent on that concrete (things like a tower base). Concrete can
corrode the wire and rod and its connection.
I prefer to isolate the RF and AC grounds so that when I'm not using the
tower antennas, I can isolate them from the house wiring so that each
time the tower is hit, the house wiring doesn't get so much of a blast.
Every time I've failed to maintain that isolation, damage has happened
in the house wiring too. I can connect AC and RF grounds for those
occasions when I need an RF ground on the radios more than the coax. I
bring all antenna cables to a jumper panel. When I disconnect the
jumpers they fall to the floor and are separated from the panel be
several feet.
73, Jerry, K0CQ
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