In a message dated 96-07-30 11:20:39 EDT, you write:
>I need some advice from the tower gurus. I am planning on erecting a 50
foot
>Rohn 25 tower on my city lot in such a way that will require one anchor
point to
>be the house itself. I am looking for advice from someone that has done
>something similar and opinions from anyone else.
>The Rohn book calls for two sets of guys at 23 and 45 feet. For the lower
guy
>point I thought I would use a house bracket and reinforce the attachment
point
>similar to this month's QST article written by Tony Brock-Fisher, K1KP. For
the
>top guys I will run two wires away from the house to elevated guyposts. The
>third guy will run back inline with the peak of the house. I propose
attaching it to a
>mast that runs vertically down through the roof peak. The mast will sit on
an
>assembly of wooden 4x4s that are attached to the ceiling joists and rafters.
>Suggestions on mast material and diameter? No waterpipe, right? It would
>probably be 6 feet tall.
Bill --
I think that the responses that you've received have been insightful
and valuable; thanks to all for their input. This is exactly what the idea
behind Towertalk was -- present a forum where questions could be asked with
input given from knowledgeable tower builders. This keeps the inquirer out
of trouble while giving the installation more reliablility.
What you've got going in your favor is that Idaho is a pretty benign
wind area; only 75 MPH max. It seems like you got lots of options, none of
which encouraged you to pursue your original plan. I've also seen house
attached guys pull roofs apart and cause other damage.
If you don't have the Rohn catalog, my recommendation is to get it. It
has housebracketed and freestanding specs in it. For example, 50 feet of 25G
bracketed at 36 and 18 feet will take 14.6 square feet of load at 70 MPH; 50
feet of 45G (same brackets) will take 34.8 square feet. Either choice will
give you a respectable load capability and reliability but obviously the
consensus is to go for the 45G and I agree. You'll never regret it. BTW, if
you'd like a copy of my free guide "The Ten Most Common Tower Building
Mistakes", send me your postal address and I'll wing you out a copy.
Thanks again to everyone for their input and I hope you all are
enjoying Towertalk as much as I am. And please tell your friends; they'll
enjoy it too!
73, Steve K7LXC
TOWER TECH -- professional tower supplies and services for amateurs
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