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SUMMARY: using house as a guypoint

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Subject: SUMMARY: using house as a guypoint
From: bfrede@poci.amis.com (Bill Frede)
Date: Wed, 31 Jul 1996 13:52:38 -0600
My original post was:

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.

Here's the deal.  The lot is 160x90 feet and is relatively flat even though 
this is a 
mountainous area.  To keep neighbors and wife somewhat happy with this setup I 
have decided to locate the base at the side of the house along the centerline.  
This 
puts it 25 feet from the side lot line.  The house is a rectangular two story. 
(32x26 
feet and 27 feet tall at the peak) 

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.  

I haven't heard of or seen a setup like I have suggested but it seems like it 
would 
be safe if properly designed and constructed.  Your thoughts?
***************************************************************

I asked for advice and I got loads of it.  Thanks to all that contributed.  I 
haven't made up 
my mind about the setup to use but here some of the ideas presented: 

1.  Don't go through the roof of the house to guy the tower because: 
*The chance of causing a perpetual leak is always there.
*A lightning hit could be conducted into the house.
*A professional structural analysis of the anchor support will probably be 
needed.
*Insurance companies may take a dim view of this method if damage does occur.
2.  Try to avoid using guys and go the self-supporting route if possible.  A 
number of 
hams use Rohn HDBX towers  and I think most ignore the 10 foot boom limitation 
set 
by Rohn.  As I understand it that type of tower is susceptible to twisting 
failure.  I live 
in the mountains of Idaho and as Steve, K7LXC, pointed out this area is a low 
rated 
75 MPH region but I am more worried about the squirrely winds around here.  I 
seem 
to get strong gusts from different directions quite often.  Another suggested 
putting up 
50 feet of 25G without guys but with an oversize base.  It works for him. Sorry 
but I 
don't have the guts to do that.
3.  Another approach suggests that since I'm not going that much above the roof 
I could 
just rely on the reinforced house bracket in the attic and have 23 feet of  
unsupported 
tower above the house bracket.  Doing this with 45G would be the preferred 
solution.  
( The top house bracket will be at 27 feet)  Tony Brock-Fisher's August 1996 
QST 
article is the basis for this solution.
4.  Another solution was to use a 4 guy system.  That would clear the house but 
I would 
run into a garage on the other side.  My wife would put up with 3 guywires but 
4 is 
probably unacceptable.

So I'll probably go with idea number 3.  If I use 25G then I can get an antenna 
up right 
away.  If I go the 45G route then I'll end up with a tower only because of the 
price 
differential.  The antenna will have to wait.  
Anyone know where to find 45G sections in southeast Idaho?

Thanks again for the help
Bill Frede   AA0WO
Pocatello, ID
bfrede@poci.amis.com





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