[TowerTalk] TH3MKII vs 3 element SteppIR

Terrence R. Redding Ph.D. terry at oltraining.com
Mon Jul 13 04:04:42 PDT 2009


I have a TH3MKII with a 30/17/12 dipole mounted five feet above the beam on
a 54 foot Tri-Ex tower.  I am thinking of replacing that with a 3 element
StepIR.  I am convinced it will be a step up in all cases.  However, I have
never seen a 3 element SteppIR and don't have a feel for whether I am
dramatically increasing the amount of stuff I have on top of my tower.

Has anyone done something like this?  I assume many have.  If so, did you
have the sense that you were putting more stuff in the air and increasing
the risk to the tower coming down in a storm.  Or was you sense that you
were reducing the wind profile and actually putting less in the air, and
thus reducing the likelihood that it all might come down in the wind?

In the pro vs cons, it appears the SteppIR weighs less and presents less
wind load.  However, the antenna is bigger, nearly four feet longer on each
side of the boom.

    Weight lb    Length ft    Width ft    Wind Load lbs    turning radius ft
TH3MKII    35    14    27.5    4.6/118    15.3
Dipole 12/17/30    20        29.56    '1.8/48    16
                   
StepIR 3 element    51    16    36    6.1    19.7
                   
I am also curious to know how long assembly takes.  I would hope I could
build the antenna during the week, and then drop the tower and install with
all cables and be back on the air on a Saturday.  Is that reasonable for one
guy?

Terry - W6LMJ West Palm Beach, Florida




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