I am far from an expert but every bracketed Rohn 25G tower I have
climbed (several) wobbled in the joints above the top bracket. The
one that I took down showed major elongation of holes in the joint
that was above the top bracket.
I once installed a guyed 25G tower with guys near the top of the
next to last section. It only had a large VHF vertical on top but
was in a very windy location. After two years the bolt holes at the
one joint above the guys were worn so much I had to replace the top
two sections.
I know Rohn gave the OK to bracketed installations for many years
(maybe still does) but personally I will never again put even one
section joint above the uppermost bracket or guys.
Paul
On 10/24/2017 07:42 AM, Clay Autery wrote:
Apologize for yet another post... After reading that document again, it
would appear that Rohn bracketed towers REQUIRE TWO brackets. Their
specs make no provision for only ONE Rohn bracket.
I suspect they've been asked the "What about ONE bracket?" question
before. Phone call is free...
73,
Clay Autery
KY5G
On 10/23/2017 11:20 PM, Terry Brown wrote:
I am trying to determine how high I can use a Rohn is 25g unguyed.
Here is my situation:
I want to sink a 10 ft section of Rohn 25g into 3 ft of concrete base. This
will leave 7 ft. Above the base. I will then attach another 10 ft. Section and
attach a house bracket at the 14 ft level. This will leave the second section
unguyed for 3 ft above the house bracket. How many more 10 ft. sections can I
add safely above that point? My antenna will be a Mosely TA33-Jr (27 lbs) wind
surface area 5.1 sq. Ft. Windload 98 lbs at 80 mph.
Rotor is Alliance HD-73.
Thanks!
Terry
--
Paul
N1BUG 160m-2m DXCC Honor Roll
WI2XTC 2200m-630m Experimental license
FN55mf ME Piscataquis County
http://www.n1bug.com
http://www.aurorasentry.com
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