[Top] [All Lists]

[Towertalk] Exterior wall feedthroug

To: <>
Subject: [Towertalk] Exterior wall feedthroug
From: (Red)
Date: Sat, 18 Jan 2003 08:47:52 -0600
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 

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

<Prev in Thread] Current Thread [Next in Thread>