[TowerTalk] 75/80 vertical

[W5CPT]

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 at 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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