[TowerTalk] CATV & Phone grounds
Red
RedHaines at centurytel.net
Tue Jul 11 12:02:21 EDT 2006
Hi, JC;
I had been pondering your earlier post regarding need for a perimeter
ground or loop. PolyPhaser made an argument in their earlier book,
Grounds for Lightning Protection, for this and I observe that commercial
installations use a perimeter ground. I don't recall the reasoning.
Perhaps someone on this list can enlighten me and others.
Meanwhile, it sounds to me like your system ties utility and station
grounds together. A consideration is minimizing impedance between
them. Copper pipe should be better than wire. I think the soldered
joints are probably ample in area and they are water cooled, and both
the resistance at RF and the inductance are less than what smaller wire
would present. Is the routing of the pipe reasonably straight? Are
the tower and station grounds composed of several ground rods or other
contacts spread over an ample area? Might you improve the utility
ground by adding some rods, spaced at twice their depth? You don't want
one ground point to be poor with respect to another.
This lightning protection issue is always a probability game. You can't
reach 100% safety and you must trade-off cost of additional features vs
their added protection. Unfortunately, I can't quantify the added
protection of some of those features.
73 de Red
JC Smith wrote:
>It makes sense that all grounds be tied together, but a question is how?
>
>
>
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