Although the large vent opening is handy for running feedlines and
control cables, it is not ideal for the ground line. The ideal ground
line should be wide, to minimize inductance. Commercial stations use
sheet copper, at least 4 inches wide.
I use 5 electrical conduits, with appropriate fittings permitting easy
access where they turn to go through the wall, They are 2 1/2 inches
apart, making a total spread of 10", which fits between two studs. The
conduits run down to my grounding box, in which the lightning
suppressers are mounted. A ground wire runs through each conduit,
creating the equivalent of a 10" wide conductor for RF grounding with
low inductance. The 10" wide array, connected to the mounting plate in
the entrance box, continues through the entrance box to the grounding
array, a radial spread leading away from the house with multiple ground
rods, under the entrance box and spaced every 16' along the radials and
the perimeter ground. This RF and lightning ground system connects to
the utility grounds and to the tower grounds. I have no RF problems in
the shack and have not lost any more equipment during thunderstorms
since installing this grounding system and a system of suppressers on
the feedlines, the power distribution, and the phone lines.
The five conduits and the entrance box is esthetically more attractive
(matter of opinion) than a bundle of feedlines, control lines and ground
lines.
If I find I need more than 5 conduits, I can bring in 4 more between the
first five, offset in height to accommodate the access boxes at the top
of each conduit.
73 de WOØW
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