The Rohn Ham Tower catalog reccommends 4 ft in the ground plus 2" down into
the gravel at the bottom of the hole, and using between 1/2 to 3/4 yards of
concrete. Your installation sounds similar to mine. I'm using 50' of Rohn 45
and a Pier pin in concrete and bracketed at 20'. Currently it's got a TH3, 8
el 2mtr and 14 el 44 beam and a 4'450 vert. I also have a guy wire from my
chimney to the 35' level and extra bracing in the attic to keep my neighbor
from claiming it in events unforseen. Jim/ NV3V
-----Original Message-----
From: Stan Griffiths <w7ni@teleport.com>
To: Jim Miller <JimMiller@PartyLine.Net>
Cc: towertalk@contesting.com <towertalk@contesting.com>
To: <towertalk@contesting.com>
Date: Friday, October 31, 1997 00:07
Subject: Re: [TowerTalk] Rohn 25 - Antenna size
>>Area is St. Louis County, Missouri - fully surrounded by 60-80 foot trees
so
>>very high wind should not be a problem.
>>
>>I have Rohn 25G tower I want to put up at the end of my house. I will put
>>in whatever size concrete base is needed (how much?). It will be
bracketed
>>to the house at 14 feet. and will be 2 sections plus the top section (29
>feet).
>>
>>1. How much antenna (sq ft) can I put up without any guys being added?
>>
>> 2. How much if guys are added near the top (I don't really want to do
>>this). I have a TA33 and a TA36 (10.75 sq ft).
>>
>>3. I would really like to put up the 36 and how much mast can I extend
>>beyond the tower (probably "none" if not guyed, right)?
>>
>>Tnx, Jim
>
>Hi Jim,
>
>I have not seen an answer to this question yet. I think you are very close
>to the limit for 14 feet or so of Rohn 25 above the house bracket with the
>36 installed on it. I would not extend the height any with a taller mast.
>I tend to like the 3 1/2 foot short base sections for the bottom since they
>are easy to install and I would pour about a half yard of concrete around
>it. Make sure the bottom of the tower legs extend through the bottom of
the
>concrete base to allow water to drain out of the tower legs. Also, make
>sure the concrete extends above ground level for a couple of inches to keep
>water from standing around the tower legs. "Crown" the center of the
>concrete to make the water will run off the base.
>
>I know you don't want to hear this, but a set of guys at the top of the
>tower would make the installation MUCH stronger.
>
>Stan w7ni@teleport.com
>
>
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