>
>Message: 4
>Date: Wed, 23 Nov 2005 09:44:56 -0500
>From: "Mark ." <n1lo@hotmail.com>
>Subject: Re: [TowerTalk] Radials, lightning ground, RF ground
>To: towertalk@contesting.com
>Message-ID: <BAY102-F834211FAF2FAA9DCC130693550@phx.gbl>
>Content-Type: text/plain; format=flowed
>
>Hello Dudley,
>
>Let me try to help clear the confusion. to the best of my understanding.
>There are three separate entities to consider:
>
(...)
>
>Now, you see, that insulated or elevated wires in an RF counterpoise or
>radial system, cannot sink any current to earth, and cannot act as an RF
>ground or lightning ground.
>
>AN RF counterpoise/ground screen having light gage bare, buried wires or
>mesh, can be both an RF counterpoise AND and RF ground, but would be burned
>up by lightning strike current.
>
>A heavy duty RF counterpoise made from #6 bare, buried copper radial wires,
>such as already described here, used on commercial broadcast installations
>(very costly), can fulfill all 3 functions: RF counterpoise, RF ground, and
>lightning ground.
>
>Hope this helps.
>
>--...MARK_N1LO...--
>
Mark,
Actually, I was aware of those distinctions in the roles of grounds and
counterpoises. However, your short treatise was extremely well written and
concise. We all should print it out and paste it into our notebooks.
I tried to articulate those differences to the OM who made the original
request, but failed to lay it out as succinctly as you did. The confusion I
expressed to Gary's response was regarding his view that the low current rf
radial system would handle most of the lightning surge. I can see that the
high frequency components couple to the ground capacitively, but I am not
sure if the light gauge wire would handle the massive current surge.
So my question to Gary is this: Suppose I install the light gauge
insulated wire radials and the few safety and ground connection ground rods
around the base of the tower/vertical. In my view, I still need to install
heavy gauge ground radials bonded to ground rods along their length in order
to handle a lightning surge. Are you implying that the second set of
lightning radials is redundant?
Dudley - WA1X
_______________________________________________
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