Rich, wind speed and antenna loading are only two of the inputs to the
engineering calculations. The biggest contributors are the tower section
projected wind surface areas, They are related to leg and brace diameters and
lengths. Brace/leg angles have an effect as well. The calculations become
quite tedious.
Then there are safety factors on top of that as well as the yield strength
of the materials used. Different manufacturers use different safety factors
and grades of materials.
73,
Gerald K5GW
In a message dated 6/10/2017 9:01:21 A.M. Central Daylight Time,
rthorne@rthorne.net writes:
This may not be comparing apples to apples but here's my question after
studying the two towers.
US Tower HDX-89 claims 9.2 sq ft of max allowable antenna wind area 90
mph 3 second gust
Tash DX86 claims 21 sq ft of max allowable antenna wind area 85 mph 3
sec gust
After looking at both designs they both start with a lower section that
is 28.75" wide and a top section that is 13 7/8" (Tash) and 13 15/16"
(US Tower)
So the designs appear to be the same, why are the allow able antenna
wind loads so different? I realize that one is based on 90 mph the
other on 85 mph. Does the 5 mph delta add up to a 11.8 sq ft difference?
Thanks in advance.
Rich - N5ZC
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|