On 7/3/2013 10:54 AM, Larry Loen wrote:
I agree with N4ZR here.
Is this the force 12 LPt1242? Constructed of square Aluminum tubing?
Force 12 lists a crank up of square Aluminum, low profile tower, but I
find no guyed towers listed. while most of the comments on here are
about guyed towers, There is a huge difference in base requirements.
That was all I could find on the LPT1242.
Find out what is required, especially of the base. It isn't just something
to keep the tower from sliding around. It is the _foundation_ of the whole
tower. The house bracket can be thought of as merely an alternative to
guying at the corresponding height.
The base of a guyed tower serves only two purposes. One is to prevent
lateral movement (sliding) and the other is too keep the tower from
sinking...Period! ROHN even sold a "dirt base" for the 25G for years.
However the proliferation of zoning regulations and the dirt base is no
longer offered. The wide variety of soil conditions was also a factor.
The base for a "crank up is substantially more complex and must be
massive enough to resist any overturning moments within the wind ratings
of the tower with antennas. Much of the size depends on soil conditions
and salt flats, or marshes usually make a very poor location for a self
supporting tower.
There are two bases for the smaller towers. In one the base is set in
the concrete, In the other there is a single pin coming up out of the
concrete. A steel plate , with a hole in the center fits over the pin
and the plate holds the legs of the tower. This is called a "Pier Pin
Base". These are slight over simplifications, but fit the general
descriptions of the bases.
The nice thing about small towers with relatively small antennas is the
minimal base required for a safe installation of guyed towers.
I'm not advocating the use of a dirt base and particularly so in a salt
marsh.
In the past I have installed full a size 5L 20 meter KLM, 6L 15 meter
KLM and a 7L 10 meter Wilson on 40 foot guyed towers on dirt bases
They were up over a decade with no problems and stood through an ice
storm back around 76, or 78 that took out over half a mile of power
line just down the road.
Check with your local zoning board for requirements.
The problem on here is we really need more information about the tower
and any information is not offered in a professional capacity. Heed at
your own risk.
As others have said "Up the ?Tower" would be a good investment.
The base AND the bracket needs to be engineered by somebody who knows, you
know, engineering. That definitely includes how the bracket is attached.
It needs to meet zoning requirements. That may or may not require an
engineers stamp and by all means follow the manufacturers
instructions,... IF the are stringent enough to meet local code.
Most house brackets for small towers are pretty light.
73
and good luck,
Roger (K8RI)
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