Mike K wrote in part >>>
Message: 2 Date: Mon, 6 Aug 2018 12:06:12 -0500 From: Mikek
<amdx@knology.net>
I have installed a 253ft Bog, ?I used WD-1A a pair and just twisted the
two wires together. Any reason I should separate the pair and just use a
single wire? Can the WD-1A be used for a Bi-directional BOG, or is the
spacing too close?
Mike:
Several things:
* I have tried bi-directional BOGs at my QTH and what I found with my
ground is that the losses on the direction using the double wire for
a return transmission line were very high, about 40 db or more when
leaves got on the antenna. I got signal at the far end, but by the
time it traveled back 250' along the parallel pair it had been
significantly attenuated. Your ground may be different; you may
want to try Rudy Severn's ground test method using an 80 meter
dipole to determine your ground characteristics, but at my QTH (WV
rocks and highly conductive clay soils) the "return BOGs" were
essentially useless, and I now use only unidirectional BOGs.
* As Guy noted, the ground characteristics can (and at my QTH
defintely do!) vary significantly, and this is another hurdle to
overcome which I suspect affects return line losses for 2-way BOGs.
* As others have noted, ground moisture can make a huge difference in
performance especially for some sorts of clay soils like those I have.
* I did find that termination of the BOGs helps with F/B, and varying
the resistance can change the pattern of one of my BOGs enough to
help null 'town noise' from a town about 5 miles away.
* getting the termination resistance right also helps with multiband
operation by keeping the impendance excursions down so that the BOG
works more consistently on 160, 80 and 40.
The things about BOGs that I like is that they are quick, cheap, easy to
install well, require no supports of any kind, and very low profile.
Regards and good luck with your BOGs!
LArry W8ANT
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