[TowerTalk] New to the list

[K8RI]

On 7/4/2013 12:07 PM, PHILIP GRAITCER wrote:
> Thanks folks, for the ideas and suggestions.
>
> I am getting the tower from another amateur, so any extra weatherproofing I will have to do outside the factory. Force 12 has sent me some info, two sets of drawings, one for the 18x18X36 base that is reinforced with rebar. Foundation bolts get set in the base. There is also a drawing for a house bracket - not very detailed, but two pieces of angle iron stick out 24 inches from the wall and  two bolts go through these pieces around the square tower. In addition there are two 36 inch pieces that run at an angle from the pieces sticking out to the wall of the house.
>
> I am going to use 2 inch angle iron against the wall of the house, secured by bolts and a plate inside the wall, and use 2 inch iron for the 24 and 36 inch pieces. If I can find aluminum that is this stout, I will use that instead of iron because of the salt air. The tower collapses down to a little more than 13 feet and weighs less than 150 pounds.
>
> I think I have a plan for setting it up, however, I just have to figure out how to pour the concrete, make the rebar cage, set the foundation bolts, and build the bracket.
>
There are many caveats about house brackets.
They run from outright  flexible to outright rigid.
Quite often the house moves more in the wind than the tower.
Anyone who has been on top of a house when it's windy can see the house 
move compared to the chimney.  I've had 3 single story home from 1100 to 
2100 sq ft. They all had fireplaces.  I could see as much as an inch 
movement between the houses and chimneys and these were maybe 30 MPH winds

BTW working on a roof in the wind is likely a lot more dangerous than 
climbing towers.

But one thing about house bracketed towers is NOISE.  The tower, with a 
rigid mount often (but not always) can end up using the end of the house 
as a "sounding board", so it might be wise to avoid a wall of a bedroom. 
<:-))

The more flexible brackets (like you can purchase at Radio Shack) 
provide decent support in a plane from the house to the tower, but 
apparently much less parallel to the wall

The last photo on  http://www.rogerhalstead.com/ham_files/Dirt_Base.htm
shows a bracket (still undrilled)that was lag bolted to the end of the 
shop roof. The end plates are 2 X 10s and form a very rigid structure.
I ended up putting a 1/4 inch of rubber sandwiched between the bracket 
and plate for sound deadening.

SOMEWHERE I have a photo of the installation, but have been unable to 
find it.
BTW I wonder how many have noticed that this is not a typical bracket in 
that it fastens to two tower legs.  The tower hinges over from the base 
at a 120 degree angle to the wall, due to a tree.

I have used a similar design to hold all three legs.  Any bracket that 
holds two or more legs requires a very strong wall as the twisting 
moment from a large antenna is transferred to the wall.

Where the house bracket may be required to provide substantial support 
with large antennas on relatively light duty towers it would be a good 
idea to reinforce the wall and use a 3/4 to 1" plate on the inside to 
distribute the load across as many studs as possible.

Newer walls using 2 X 6 studs are stronger, even with the wider spacing 
and quieter when the inside and outside surfaces are isolated from each 
other.

Don't get discouraged from what you hear on here.  Let your zoning board 
do that. <:-))

73 and good luck,

Roger (K8RI)
>
> Thanks for your tips.
>
> 73,
> Phil, W3HZZ
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