Art, I don't have specific experience with what you're doing but here
is info I have from an older Rohn Consumer Products guide.
Drawing #A871302 in my Rohn book has a chart for 25G Bracketed Tower.
They show the following for a 50ft tall tower...
Upper Bracket: 30 ft., Lower Bracket: 15 ft.
14.6 sq. ft. of antenna up to 70 MPH
10.0 sq. ft. of antenna up to 80 MPH
6.8 sq. ft. of antenna up to 90 MPH
The recommended foundation detail for this type of bracketed
information is:
2 ft., 0 in. round or square hole that is 4 ft., 6 in. deep. The
bottom 6 in. is compacted sand/gravel for drainage with the tower legs
a minimum of 2 in. into the gravel. They also specify a 4 in.
projection of the concrete above ground level.
I think with the peak of her roof being 14 ft. as shown in your sketch
and the antenna she's using guys would be in order if we assume Rohn
knows what they are doing.
They show 50 ft. unbracketed 25G towers being guyed at the 23 ft., and
45 ft. levels.
Tim, N9PUZ
Art Trampler wrote:
> She is wanting the tower up against the house, rather than having
> us move her vertical. She has five sections of 25G, will have one
> section sunk in concrete for the base, and will be putting up a
> Cushcraft ATB-34 yagi on it.
>
> Putting it against the house raises some issues as to guying the
> tower, but what would be the safe height for this, unguyed, if we
> were to house or eave-bracekt the antenna?
>
> She is southeast of Oklahoma City, so yes there will be winds from
> time to time.
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