The impedance drops greatly as the wire approaches ground. If your Beverage
actually lies on ground, it's likely to have an impedance of around 200
Ohms. On grass / shrubs /etc it will likely be a bit over 300 Ohms,
depending on your soil of course. I choose to ignore the lower impedance and
use my normal 450 Ohm transformers. I don't feel the slight signal loss
hurts me at all.
FYI: the velocity factor also drops greatly, making the antenna appear much
longer than it really is. That narrows the bandwidth and lowers the
elevation angle of peak response. BOG's can easily appear 25 - 50% longer
than their elevated counterparts.
Chuck
-----Original Message-----
From: topband-bounces@contesting.com
[mailto:topband-bounces@contesting.com]On Behalf Of Dick
Sent: Sunday, December 07, 2003 3:41 PM
To: Topband@contesting.com
Subject: Topband: BOG...
I assume that the term BOG is a Beverage on the ground...are there any
special parameters or matching requirements that are different than my
normal Beverages...I have heard of Mars stations using coax laid out on the
ground to both receive and transmit in an NVIS pattern with good
success....Could a BOG be used in this fashion...tnx Dick
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