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Re: [TowerTalk] Mixing Rohn 20G and 25G

To: towertalk@contesting.com
Subject: Re: [TowerTalk] Mixing Rohn 20G and 25G
From: "Roger (K8RI) on TT" <K8RI-on-TowerTalk@tm.net>
Date: Tue, 01 Jul 2014 20:03:09 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
On 7/1/2014 10:59 AM, Wayne Kline wrote:
I also have experience with 20-G and 25-G towers... @ my station my 2mter/450 
MHZ  and one 6 meter beam
  5 element 14' boom  are on at 36ft. an consist of  3 sections of 20-G and a 
top of 25-G  AG3 ?   it's house bracketed @ 18 ft.
Been in place for 24 years  BUT  extremely light wind load.
IMHO @ HF a C-3. TA33 or A3 would be the BIGGEST .

Remember, 20G is only rated for 2 sq ft of wind load...IE a TV antenna. They, like many ham installations with other towers have supported much more than their ratings, but you are far past the ratings and who knows how close to the ultimate load and at what wind.

I'd not mix them, nor put mote than a 2-meter yagi, or a light weight 3L 6-meter if it's close to 2 sq ft. and then only if I was willing to sacrifice the antenna and it wouldn't hit something expensive or electrical.

73

Roger (K8RI)

So my question to you is WHAT are you planning to adorn the tower with ? Wayne W3EA . .

Date: Tue, 1 Jul 2014 07:42:14 -0500
From: kkbroadcastengineering@gmail.com
CC: towertalk@contesting.com
Subject: Re: [TowerTalk] Mixing Rohn 20G and 25G

Nathan,

I would caution you to not mix the sections nor even use the 20 for
anything more than VERY light duty use.

With that said...  Back in my younger days when I did a lot of tower work
for CB and Ham operators, there were a number of mixed 20/25 towers
supporting large CB antennas and they stayed up many years.  I do recall
working on one where the 20 top section physically broke during a wind
storm.

Climbing a mixed 20/25 tower is a real pain as the steps are different
distances apart.

Good luck,

Kevin C. Kidd, CSRE/AMD
AM Ground Systems Company  -  WD4RAT
kkidd@kkbc.com  --  866-22-RADIO -- 866-227-2346
www.amgroundsystems.com


On Mon, Jun 30, 2014 at 7:42 PM, Linux Mercedes <linuxmercedes@gmail.com>
wrote:

Hello,

Whilst moving tower sections from the shed to the shop so I could clean
them up and make a couple of fixes before putting up my tower, I noticed
that some of them seemed lighter than others. Turns out I've got a mix of
20G and 25G sections.

What are your thoughts on putting up, say, 30 or 40 feet of 25G and then
another 20 or 10 feet of 20G? I'd like to use the best sections I have on
the tower, but if mixing is a no, then I'll fix up some of the other
sections I have and build a homogeneous tower.

Thanks,
Nathan
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