You need to pay attention to the definition of the terms and the "units of
measure' for the terms.
Winload is confusing. Winloading is the weight or FORCE that the antenna
becomes when a speed of wind is applied.
This force is applied to the mast, rotor and tower by the wind pressure on
the antenna. This is measured in pounds.
Surface Area (square feet) this is the cross-sectional area of the elements
and boom.
Wind survival or Wind Rating as Steppir calls it, is a MPH spec. Above that
speed, some or all of the antenna will fail.
The tower will fail at full extension of height with a wind speed above 76
MPH and 7.4 sqft of round tube antenna on it.
But when you know that will be coming, you will most likely crank it down.
(The 4.2 sqft is a different "load" on the tower.
This is often called flat panel load.)
ANT Surface_Area Wind_Survival
=============================
BD36 = 17.5 sqft of surface area & the wind survival speed is not quoted by
the manufacturer.
DB18 = 10 sqft of surface area & survives 100 mph.
3 ele yagi + 30 or 40 = 8.1 sqft & survives 100 mph.
If you commit to cranking down your tower before high winds, then your
tower's wind survival speed will be higher
than 76MPH because it is not extended and not at its weakest.
Once youve lowered the tower, then your next concern is antenna wind
survival and forces applied to the rotator.
Those specs should be closely followed.
Good luck and enjoy your tower.
-Charlie N1RR
On Fri, Jul 6, 2018 at 12:17 PM, Aaron Mcclure <aaronm10000@comcast.net>
wrote:
> Hi Everyone,
>
> I just got done pouring the base for my TX-455 and will use my Mosley 3
> ele beam until I can settle on a new one.
>
> My question is wind load of the TX-455. There does not seem to be any
> clear-cut specification for the tower. The design specs list 76mph and 7.4
> sqft wind load all round members or 4.2 sqft square. In the Archives I have
> read of people installing DB36 with 17.5 sqft wind load. This seems way
> over the spec and if the tower came down I assume US Towers would point to
> that as the failure.
>
> I would love to install a DB18 with 10sqft so I have some more gain on
> 30/40 M but would happily settle for 3ele Yagi with the 30/40M dipole at
> 8.1sqft. The antenna spec lists 100mph. Is this the wind load at 100mph?
> How does it translate to the feeble US Towers wind load of 7.4sqft at
> 76mph? Would I be safe with the DB18 or should I be conservative with and
> stick with the 3 ele and dipole.
>
> 73s
>
> -Aaron
>
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>
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