[TowerTalk] Holy SteppIR!

[Michael Tope]

----- Original Message ----- 
From: "Clay Curtiss W7CE" <w7ce at curtiss.net>

>
> While a 5 degree take-off angle might seem too low for many contacts, I
> understand that he can control both azimuth and elevation of the array.
> With a single yagi, elevation control doesn't buy much, but when you stack
> antennas it does.  I ran simulations and at 20 degrees elevation the gain 
> is
> 17.3 dbi at a take-off angle of 23 degrees.  At 40 degrees elevation the
> gain is 16.3 dbi at a take-off angle of 40 degrees.  Below 20 degrees
> elevation, the take-off angle is not well defined, but increases at angles
> above 5 degrees.  As the elevation angle is increased, the ground gain
> disappears, but the resulting gain is still very good.  It looks to me 
> like
> he'll be able to pick the elevation that works best for any contact.
>

Interesting, Clay. I went back and looked at the pictures more carefully
and indeed it looks like he has elevation control as well as azimuth. As you
point out, this will allow him to adjust the take-off-angle. What it won't
give him is the broad vertical lobe fill that you get from an optimized 
stack,
so it will still be a compromise for contesting. For DXing, assuming he
gets it pointed correctly, he should be the first guy through most of the
time. Really puts my inverted-vees at 60' to shame. Guess I should have
listened to an early engineering mentor who suggested that I should become
a chiropractor :)

Mike, W4EF.....................................................