[TowerTalk] Strongest mast material?

[Stan or Patricia Griffiths]

There is another way to beef up a long mast without using the largest material
you need clear to the top.  You can taper a mast just like you would taper an
element.  For example, W7WHB wanted a tall mast to stack three monobanders.  We
started with a piece of 2.5" OD 0.250" wall steel tubing for the first 16 feet or
so.  At that point, a piece of 2" OD 0.250" wall steel tubing was inserted inside
for a bout a 1 foot overlap and the two were welded together (not pinned since
the pin holes would significantly weaken the mast).  The 2" mast would not slide
easily into the larger one so a very small amount was removed from the outside of
the 2" mast where the overlap was to occur.  There were a VERY tight fit between
these two pieces and then they were welded together.  This mast has been up since
about 1977 with the three monobanders on it.  The tower is 140 feet of Rohn 45
and the top antenna is at 156 feet.

Stan  w7ni@teleport.com




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