I had a 75 foot 25G tower up for 8 years...one of the guys was attached to
the top of a drill stem (I don't remember the OD, maybe 6" or 8") which was
4' in the ground (in cement) and about 12' above ground. It never bent or
loosened up. Worked just fine. I thought about back guying it once, but that
was never necessary.
Allen Brier N5XZ / KL5DX
1515 Windloch Lane
Richmond, TX 77406-2533
281-342-1882
713-705-4801 (Cell)
n5xz@arrl.net-----Original Message-----
From: Donald Hofmann [mailto:electroubleshooter@hotmail.com]
Sent: Friday, December 12, 2008 1:29 PM
To: 'Gregg Seidl'
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] rohn 25g questions
Thanks
I can't use a trencher due to obstacles in the way - propane tank, water
well house, etc. I could use direct burial cable and just bury it a few
inches deep but it would take me an extra 10' to navigate around all of the
obstacles
Is your worry that the pipe will bend or pull out of the ground? Drill stem
is hardened and will not bend. If the guys are tensioned to 400 lbs then I
figure that the most that the wind could add would be 1000 lbs total force.
I don't think that the pipe would budge, as 4' isn't enough leverage.
Some guys use 1/4" thick pipe as much as 8' tall, others use I-beam. If the
worry is that it will loosen in the ground, then the same goes for I beam,
etc. In my hard clay with sandstone, it won't come out of the ground.
Thanks
-----Original Message-----
From: Gregg Seidl [mailto:k9kl@centurytel.net]
Sent: Friday, December 12, 2008 2:31 PM
To: Donald Hofmann
Subject: Re: [TowerTalk] rohn 25g questions
Th flat plate top sections are great. Your idea of guying them to a large
pipe won't work. The guy anchors WILL loosen up and start to tilt over a
year or two. Why don't you just rent / borrow a trencher and bury the
cable?? check out www.k9kl.com Gregg K9KL
----- Original Message -----
From: "Donald Hofmann" <electroubleshooter@hotmail.com>
To: <towertalk@contesting.com>
Sent: Friday, December 12, 2008 10:41 AM
Subject: [TowerTalk] rohn 25g questions
>
> I installed 30' of Rohn 25G in the early 90's. It is self supporting with
> 3' of the base in concrete (3x3x3'). I had two Channel Master antennas on
> it.
>
> Now that I am into ham radio, I want to heighten the tower to 50'
> (actually 47') guy it and put a beam or two on it.
>
> Here are my questions:
>
> 1. Over the years, the tower has started leaning- probably from the
> shifting of our soil. When I guy it, how much should I try to straighten
> it? I would guess that it is leaning about 5 degrees, as it is visible
> with the naked eye.
>
> 2. I will have to replace the current 25ag top section so as to use a 2"
> mast. I am looking at the 25ag4 flat top and tb-3 thrust bearing instead
> of the 25ag2. My reasons being- the flat top has tabs for guys avoiding
> the need for me to buy a star bracket or other assembly and two, the flat
> top will be a good place to stand while attaching antennas. Also the
> bearing makes less work and strain for the rotor. Comments?
>
> 3. Due to space restrictions I can set the guys 30' from the tower base.
> They will be attached to 7' of heavy pipe with 3' in the ground in
> concrete. Is this adequate? I will use two guys per side. 4' high for the
> guys should help increase the guy angle as well as increase their height
> to keep things from hitting them.
>
> 4. I plan on running the coax down the tower to about the 15' level then
> across the air into the gable end of my shack. I will run a piece of guy
> wire to support it and then loosely tie the coax and rotor cable to it
> with cable ties (like a clothes line). It is about a 40' run so I am sure
> that it will sway some in the wind. Should I use LMR400 or LMR400 flex so
> that it will not break in the wind? The total run will be about 125', is
> LMR400 adequate or should I run something better?
>
>
> Thanks
>
> W5DWH
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