John,
Just FYI, I would direct you to an excellent article written by Tony
Brock-Fisher, K1KP called "Install a House-Bracketed Tower -- the Right
Way!" In the August 1996 issue of QST. Unfortunately the article is not in
pdf format on the ARRL website (none of the GOOD articles are! :-P).
Tony had a P.E. friend of his go through the calculations and design of a
house bracketed tower. The design is VERY sturdy and is worth the extra
work. I built mine like this and it has been great. I will try to attach
some photos (in an offline email) of what it looks like from inside the
attic.
I don't think you'll need two separate house-mounts.. Just one will do just
fine if its done right. OFFICIALLY, you can go up 20 ft from the point at
which the tower bracket hooks to the tower. I would feel comfortable going
up another 10 ft or so, but beware when you climb it (espeically if its Rohn
25G like mine) that you will be rockin' and rollin' when you're at the top.
It can be very un-nerving if you're not used to it. Guys would make it much
more stable up top.
I've been running a single 2m Yagi at the top of my tower for a couple years
now. I'm planning on adding some antennas and going up another section in
height-- I'm going to add some guys because there is a little more movement
at the top than I'd like to see.
Good luck and have fun!
Jason
P.S. You will find a HUGE amount of information on the Tower Talk
reflector/archives. Just about anything you would ever want to know about
towers & antennas is posted over there!!
-----Original Message-----
------------------------------
Message: 2
Date: Sun, 3 Jul 2005 03:20:49 -0000
From: "John Geiger" <ne0p@lcisp.com>
Subject: [VHFcontesting] Guying a Rohn Tower
To: <towertalk@contesting.com>, <vhf@w6yx.stanford.edu>,
<vhfcontesting@contesting.com>, <wsvhf@mailman.qth.net>,
<cq-contest@contesting.com>
Message-ID: <001401c57f7e$36261740$3a704143@lcisp.com>
Content-Type: text/plain; charset="iso-8859-1"
I am in the planning stages for getting a tower up in the next couple of
years (hopefully) and am hoping to get some feedback from the group
concerning this. Here is my situation: I don't have much room for guy
wires in my yard, nor a desire to have guys running all over my yard. I
wonder if I could go with Rohn 25 or 45 unguyed, as I could use house
brackets on 2 sides to help support it. I would like to have 40 feet or so
of tower, with a 2 element tribander (16 pounds), a cushcraft 13B2 (5
pounds), and a Cushcraft 719B (3 pounds) mounted on the mast-whatever that
weights. Is this a reasonable setup, or would Rohn 25 or 45 have to be
guyed, even with the house brackets?
Or any other suggests for an unguyed tower or mast? Trying to keep the cost
down a little also.
73s John NE0P
_______________________________________________
VHFcontesting mailing list
VHFcontesting@contesting.com
http://lists.contesting.com/mailman/listinfo/vhfcontesting
|