I know someone will point out that this is anecdotal evidence (it is), but I
can show you a HDBX 48 that for years held up a HyGain TH11DX. The first time I
saw it was the mid 90s. The HG came down in the late 90s to put up a CC X-7
which is up there today. Both those antennas violate the 10' rule. The tower
is bolted to a concrete pad and bracketed at about 10 feet with a home made
bracket. So the twisting moment is all within 38'. It is still there to the
best of my knowledge.
I think the 10' rule came from the original manufacturer, Spaulding, who made
similar but much flimsier towers. Rohn, continued it in all their specs when
they bought and re-engineered the BX series.
No engineering - just observations.
Clint - W5CPT
----- Original Message -----
From: Gene Smar
To: Tower and HF antenna construction topics.
Sent: 24 February, 2010 11:06 AM
Subject: Re: [TowerTalk] Rainbow Towers
Bill:
One caution about the BX series of towers. As Rohn literature states,
they really are not designed for antenna booms longer than ten feet. Longer
booms have a tendency to twist the tower in strong winds. When this
happens, it stresses the rivets that hold the sections together beyond their
yield point. The tower twists itself apart.
Caveat Amateur.
73 de
Gene Smar AD3F
----- Original Message -----
From: "William Osborne" <wosborne44@gmail.com>
To: <towertalk@contesting.com>
Sent: Wednesday, February 24, 2010 9:44 AM
Subject: [TowerTalk] Rainbow Towers
> Rainbow towers in Newton, NC seems to have excellent prices on Rohn BX
> series towers. Has anyone done business with them? If so how did it go?
> Can
> one climb the BX towers without too much trouble?
>
>
>
> Thanks
>
> Bill, K5ZQ
>
>
>
> _______________________________________________
>
>
>
> _______________________________________________
> 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
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|