Gregg,
I am sure you will get all kinds of technical advice but I will offer some
anecdotal stuff.
Not too many years ago a local radio station gave the college ham club a bunch
of Rohn 25G that had been their antenna for the taking down. The club used
what they needed and sold off the rest. I got some. Every piece has a worm
screw tightened band clamp (hose clamp) on each leg and both ends. Under each
was the remnants of the copper braid, which appeared to be 1/4" wide. These
were obviously where some engineer thought it necessary to electrically jumper
each leg at every joint. Given that Rohn is galvanized and galvanization is
not the greatest at getting a good electrical connection, I say the engineer
had a decent idea. I don't know if I would do EVERY leg but I would do at
least one all the way up. Cheap insurance to make sure you have a solid
connection.
- my opinion and worth what you paid for it -
Clint - W5CPT
----- Original Message -----
From: Gregg Seidl
To: TowerTalk@contesting.com
Sent: Friday, March 20, 2009 10:56 PM
Subject: [TowerTalk] 75/80 vertical
Well now that most of the snow has melted its time to finish last years
antenna projects!! My question is this: I installed 60 feet of Rohn 25
insulated from ground. I used the tapered top section as I'm going to use a
peice of pipe to "finish" the length. I'd like it to resonate at 3.8 Mhz.
About how much pipe do I need to add to make it work. I have one of Array
Solution AS-80 tuners. I will be using about 60-80 radials about 60-100 feet
long. Tha way the tuner works is it needs to resonate at 3.8 or so and then
it switches in inductance to tune it to 3.5 and 1.8.
Does Rohn 25 typically make a good connection between sections? I was
thinking about running a piece pf copper wire from bottom to top secured
with some copper-ox and circle clamps. Good idea or?? Thanks Gregg K9KL
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