Are you worried about ground simulation or real operation over real ground?
I run mine over steep and highly variable terrain, and my Beverages are
neither perfectly straight nor at constant height. At one point one zigzags
through a clump of young redwoods, and there is no way to avoid it.
To my mind, the saving grace is derived from the equation for the impedance
to ground--it's logarithmic. That means the impedance does not change
radically with height change. For example, for a single-wire Bev over
ground, halving or doubling height changes the impedance by 138*(log 2) or
less than 42 ohms. So, for a height that provides, say, 470 ohms, that
radical height change results in a 10% impedance change--no biggie.
I don't think there is any need to be overly anal about height. Let the
practical aspects of your situation determine your actions. For example, if
you have critters, e.g. deer, you want to above antler height. If you need
to go high to clear a road or a gully or canyon, just do it. Otherwise, 6
feet is a good height, because you can reach it for maintenance. Lower
heights have lower gain and way higher heights act less like Beverages.
As always in ham radio with real-world issues, you do what you can with what
you have.
Garry, NI6T
-----Original Message-----
From: topband-bounces@contesting.com
[mailto:topband-bounces@contesting.com]On Behalf Of D Andersen
Sent: Sunday, December 28, 2003 10:34 AM
To: Topband@contesting.com
Subject: Topband: Beverage w/ground simulation
Hello,
Is there any way to run a beverage over a canyon and maintain a ground
simulation. i.e... Keep the beverage thinking that it is near lossy earth
while it may be 30' above the ground before it returned to a lower height
past the canyon.
Thanks,
Don w7dd
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