At 6:58 AM -0700 9/16/97, TOMK5RC@aol.com wrote:
>I've also received my "welcome" to Nevada, trying to put in my first tower
>base. As you mention, after six inches it is rock and more rock. I took a
>queue from my elmer, Sam Harris, W1FZJ, who was never encumbered by natural
>obstacles. I cut down a pine tree with an 8" base, placed the Rohn base
>section over it, secured the tower to the tree with angle iron, placed a 2' x
>2' x 2' wooden form around the whole thing and poured it full of concrete.
Hi, Tom.
I'm a bit concerned about the status of your tower base when the wood of
the tree eventually decays and effectively places a large void in the
center of your concrete.
>As far as grounding, I've been reading Polyphaser's literature and will opt
>for burying radials instead of ground rods. I'm still pondering the whole
>"burying" problem, since I have a 200' run to the shack and I live on open
>range with wild horses who love to dig and kick up their heels!.
Polyphaser doesn't recommend energy-dissapating radials much longer than 50
feet or so. After that distance, the radial material tends to exhibit
sufficient inductance to limit further dissipation.
I would suggest you rent a "ditch witch" and bury conductors with as large
a surface area as you can afford. Because lightning energy is RF, it
relies more on surface affect than on cross-sectional area. In other
words, half-inch copper pipe would be just as affective as half-inch rod.
As a matter of fact, the coper pipe would actually be better than an
equivalent diameter rod because the pipe would provide two RF conductive
surfaces, while the rod would only provide one.
1-1/2 inch copper strap provides roughly the same surface area as 1/2 inch
pipe, but it is a lot easier to work with and also provides the added
benefit of encouraging sharp edge sparking to the surrounding soil.
>The saga will continue....
Please keep us all advised how you progress in your "western battle."
73, Dick
--
Dick Flanagan W6OLD CFII Minden, Nevada (South of Reno)
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