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I have always used windload forces to calculate safe mast and tower =
loading. =20
If I understand the recent postings correctly, it appears to me that the =
new specs from Hygain result in lower calculated windload forces for =
their beams than before. They included the boom in the old effective =
area figure but now say to use only the element or boom figure, =
whichever is larger. =20
For example, the old effective area of a TH7 was 9.4 sq ft. Now, =
applying a .66 shape factor to the new element flat area spec of 11.5 sq =
ft, the effective wind area of 7.6 sq. ft. That's quite a reduction! =
No wonder I have never bent a mast or tower hi!
Have I got this right?
73, Ed
Ed Jensen, K5ED, El Paso, TX, k5ed@dzn.com
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<DIV><FONT color=3D#000000 size=3D2>I have always used windload forces =
to calculate=20
safe mast and tower loading. </FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>If I understand the recent postings =
correctly,=20
it appears to me that the new specs from Hygain result in lower =
calculated=20
windload forces for their beams than before. They included the =
boom in the=20
old effective area figure but now say to use only the element or boom =
figure,=20
whichever is larger. </FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>For example, the old effective area =
of a TH7 was=20
9.4 sq ft. Now, applying a .66 shape factor to the new element =
flat area=20
spec of 11.5 sq ft, the effective wind area of 7.6 sq. ft. That's =
quite a=20
reduction! No wonder I have never bent a mast or tower =
hi!</FONT></DIV>
<DIV> </DIV>
<DIV><FONT size=3D2>Have I got this right?</FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>73, Ed</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT color=3D#000000 size=3D2>Ed Jensen, K5ED, El Paso, TX, <A=20
href=3D"mailto:k5ed@dzn.com";>k5ed@dzn.com</A></FONT></DIV></BODY></HTML>
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