I must have missed the permit aspect, that brings another dimension into
it. I was thinking only about strength and ease of installation and
maintenance, which is all I ever think about on my own stuff.
-Steve K8LX
On 5/11/2015 8:28 AM, Bry Carling AF4K wrote:
I agree with Roger. I have a permit to pass here and the inspection will not
look kindly on a
Tower that has been cut and modified I am sure. It's simple enough to go buy a
longer mast.
I lean toward mounting rotators a little further down in the tower, even
just 2 or 3 feet further down. The top spot on R25 has no diagonals and
it's a very weak point in any install that has much wind loading above
the tower top. I've seen R25's fail right there.
If you select a location in the middle of the section, it's easy enough
to fab a bolt-on replacement for whatever structural members are
removed. This way rotator servicing is a breeze and the installation is
much stronger.
Cutting a brace is not an option to me. Why cut a brace which is
structural? You are trying to fit a shelf or metal plate, which is not
structural, into a tower section. It makes sense to cut the non
structural insert/shelf/plate. I do remember that I could not insert
the rotator (Ham IV) between braces and had to lower it down through the
section while others could (It's in the archives), so there must be some
variability in the brace spacing, or 25G look alike towers. In your
case if the rotator would not fit between the braces, you would need to
insert the rotator first (from the bottom of the section and move up the
section, then insert the shelf where it would fit modified if necessary
as I don't think lowering from the top is not an option.
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