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Re: [TowerTalk] Can?t add egg insulator...

To: herbert.schoenbohm@gmail.com, towertalk@contesting.com
Subject: Re: [TowerTalk] Can?t add egg insulator...
From: TexasRF--- via TowerTalk <towertalk@contesting.com>
Reply-to: TexasRF@aol.com
Date: Mon, 14 Dec 2015 12:01:06 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Here is what Rohn said in a 1980 catalog:
 
25G can survive with 33 ft maximum height above a well placed bracket with  
a 2 sq ft antenna and 70 mph wind. This configuration is intended to be 
used  with tv antennas, not with the larger antennas used by us.
 
Going through the published numbers, by the time the wind reaches 90 mph,  
the tower is about 10% beyond survival ratings with no antenna load at  all.
 
Guy wires are our friends!
 
73,
Gerald K5GW
 
 
 
 
 
In a message dated 12/14/2015 10:28:09 A.M. Central Standard Time,  
herbert.schoenbohm@gmail.com writes:

I  thought that you could safely put 30 feet of Rohn 25 un guy above a 
good  house or side building bracket.  That is what I use here for an  
10/12/ and six meter tower but to get to 60' I have a set of Phillystran  
guys at the rotor plate.  The house bracket is in to 2X6 and they are  
back by a long 1 X4 .of treated lumber with over sized washers and  nuts.



Herb Schoenbohm, KV4FZ


On 12/14/2015 10:29 AM,  Chuck Dietz wrote:
> And I would not hesitate to put up 30 feet of Rohn  25 with only one set 
of
> guys at the top.
>
> Chuck  W5PR
>
> On Mon, Dec 14, 2015 at 8:27 AM, Chuck Dietz  <w5prchuck@gmail.com> wrote:
>
>> A couple of inverted V  antennas could help the guying of a small roof 
top
>> tower  too...
>>
>> Chuck W5PR
>>
>> On Mon, Dec  14, 2015 at 7:19 AM, Ed Sawyer <sawyered@earthlink.net>  
wrote:
>>
>>>
>>> Stan, K5GO said "At risk of  purists saying absolutely not, if I were 
going
>>> to put up just  30 feet of 25G tower and didn't have all the proper
>>>  materials
>>> to insulate the guy wires and guy it as would  normally be done, I 
wouldn't
>>> hesitate for a moment to put two  levels on that small tower using 3/8"
>>> diameter polyester  (Dacron) low stretch rope. The antenna will blow 
apart
>>> first  eliminating a potential problem and rope doesn't  rust."
>>>
>>>
>>>
>>> I would  second Stan's suggestion for 2 reasons: 1) a spider beam is  
going
>>> to
>>> collapse anyway under a really strong  Hurricane wind and 2) whenever
>>> someone
>>> says  "rooftop" tower, what they really are saying is "how strong are  
my
>>> anchor points anyway?".  This is all about the ability  of the guy 
anchors
>>> to
>>> support the pull of the  tower in wind.  Rarely is any roof connection
>>>  system
>>> up to the task.  By support with a strong rope,  you kill many birds 
with
>>> one
>>> stone and you  likely don't add any weakness vs the anchor  points.
>>>
>>>
>>>
>>> I had  a 60 ft tower of 25G support by 2 sets of rope guys for 5 years  
as
>>> my
>>> 160M vertical.  It was heavy rope  and there was a plate under the 
tower.
>>> It
>>> was  purposely not permanent because it was on a farmers land.  I had  
to
>>> remove it when the land sold.  Now I have 2 T top wire  verticals -  
phased.
>>>
>>>
>>>
>>>  Ed   N1UR
>>>
>>>
>>>
>>>
>>>
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>>>
>>>
>>>
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>>>
>>
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