Wind drag over tubes essentially acts perpendicular to the axis of the tubes,
thereby transferring the drag force axially to the boom, which creates a torque
moment about the mast because of the short moment arm (distance from centerline
of boom to mast - usually a few inches). Example: 50 lbs total element drag
force x 2 inches = 100 inch pounds, or about 8 ft lbs of torque. Typically
negligible in the big scheme of things...
Matt
KM5VI
-----Original Message-----
From: TowerTalk <towertalk-bounces@contesting.com> On Behalf Of Chuck Dietz
Sent: Sunday, September 17, 2023 7:22 PM
To: K7LXC@aol.com
Cc: dcharing@gmail.com; stevewalter90@gmail.com; towertalk@contesting.com
Subject: Re: [TowerTalk] Opposing boom to mast plates?
Well my masts are very heavy. Weight of the antennas is not a real factor.
And saying someone is not an engineer doesn’t help either.
I believe It is a fact that the wind forces on Yagi antennas pointing in the
same direction are transmitted to the mast in the exact same manner regardless
of which side of the mast they are clamped to. It is a fallacy to think that
they would exert force in the opposite directions and cancel.
Chuck W5PR
On Sun, Sep 17, 2023 at 4:03 PM <k7lxc@aol.com> wrote:
> > They were minimizing eccentric loads off the vertical centerline by
> putting one on either side. It won't do anything for reducing turning
> torque or wind loading, of course.
>
> Looks like you're not a Professional Engineer.
>
> Cheers,
> Steve K7LXC
> TOWER TECH
>
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