I came across a study of commercial towers about ten years ago by some NJ
engineering firm. They studied how large towers failed (300-2000' towers) and
concluded that in all of the failures they studied (I don't remember how
many) none had fallen farther from the base than 30% of the height. (It
isn't certain that smaller towers would fail in the same way.) I think the
details ended up with Chris Imlay, N3AKD, the ARRL's general counsel.
73 Tom
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E-mail: frenaye@pcnet.com
Tom Frenaye, K1KI, P O Box 386, West Suffield CT 06093 Phone: 860-668-5444
>From Doug Grant <0006008716@mcimail.com> Thu May 9 02:41:00 1996
From: Doug Grant <0006008716@mcimail.com> (Doug Grant)
Subject: Ground Rod Techniques
Message-ID: <72960509014127/0006008716DC3EM@MCIMAIL.COM>
W0UN wrote:
>I also pre-tape my sledge hammer handles with whatever
>bulky tape I can find. Usually just some duct (no, not duck)
>tape for a few layers, then anything I can find to add some
>absorption such as an old wash cloth or dish rag or shop towel
>and then wrap some more duct tape over the top.
What I want to know is:
would this work better with Scotch 33 or 88 tape?
Or I am I getting cross-threaded?
Doug K1DG
>From Fred Hopengarten" <k1vr@k1vr.jjm.com Wed May 8 04:40:56 1996
From: Fred Hopengarten" <k1vr@k1vr.jjm.com (Fred Hopengarten)
Subject: Elevated cable runs
Message-ID: <319017ca.k1vr@k1vr.jjm.com>
On Tue, 07 May 1996 06:03:21 -0300, jon.zaimes@dol.net [AA1K] wrote:
[At my last QTH . . .]
> One or two of the runs were of the "potted"
> variety designed for direct burial, but most were not, just the regular
> hardline.
While I was in the cable TV industry, I bought a lot of
hardline. There are actually two types of cable designed
for burial: potted, and armored. The difference in use has
to do with how much abuse you expect.
If I were burying cable in sandy or clay soil, with no
rocks, especially in a non-critical application such as the
one Jon described (using hardline to power rotators), then
I'd say there is no special reason to use "direct burial"
cable.
If you have rocky soil, you can bet that one day a rock will
try to work its way through or around your cable, and a
self-healing (flowing potting) cable is advisable.
If, as I was, you are running 75 ohm hardline through the
gardens and under the lawns of condo owners, who have no
idea where you buried anything, and who employ gardeners who
don't care where anything is buried, armored cable is
desirable. It is hard work to cut armored cable with a hack
saw. It just laughs at a rock or shovel.
--
Fred Hopengarten K1VR
Six Willarch Road * Lincoln, MA 01773-5105
home + office telephone: 617/259-0088 (FAX on demand)
internet: k1vr@k1vr.jjm.com
"Big antennas, high in the sky, are better
than small ones, low."
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