On 7/29/2013 9:52 PM, Stan Labinsky Jr. wrote:
Gentlemen, ladies, I'm in the process of repairing my standalone garage
(replacing some of the Dutch Lap siding and of course, painting) to use
as the upper support (by wall bracketing) for about 40 ft of 25G.
Rohn says that 40 ft of it can stand unguyed, but probably with not too
much of an antenna.
and a good base.
My plans are for a TA-33 and maybe a smaller six meter beam above it.
Would stand thirty feet above the roofline.
The upper bracket would attach to the tower just below the first to
second section joint.
How high is the roof line?
That sounds pretty low for a bracketed tower, or will you be using guys?
That I've drawn up a bracket made out of Unistrut,
which to me, looks to be more substantial than the factory offering for
far less cost. If curious, I can attach a jpg of it to a follow-on note,
just don't know if the reflector will pass it.
Question(s):
I have the choice of using a base plate (all this courtesy of an SK
estate sale) listed in the catalog as the BCP25G, but planning rest it
on the ground with an 8 foot ground rod set as the pier pin.
If you use the rod as a pier pin, it will need "ears' welded on. The
rod alone will not offer enough resistance to keep the tower base steady,
I know
that galvanized on earth is not a good plan and would probably coat it
with some sort of undercoating as a protectant.
I've buried tower bases for years. Some were galvanize and some were
painted. http://www.rogerhalstead.com/ham_files/Dirt_Base.htm
Or, I can build another wall bracket and attach the lower end of the
tower to the wall as well, set at about a 1/2 foot above ground level,
the tower legs setting on some concrete pavers.
Normally the pier pin approach keeps the base from moving, but prevents
the tower from twisting in the wind. A bracketed or self supporting
tower needs the base held rigidly in a sturdy base. Larf=ger for the
free standing.
My concern would be, using only option two, that the two point leverage
against the wall might be excessive where using just the pier pin and
upper support would put less twisting stress on the wall.
That's one of the reasons for the rigid base on a bracketed tower.
Or, I could use both at the tower bottom, but see that as over-kill...
either-or. Also, suggestions on an on-earth undercoat for the base?
Depends entirely on the soil and moisture content.
I've never had one rust, but a friend who lives less than two miles from
me had two legs on a tower fail. Completely rusted through.
73
Roger (K8RI)
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