I too would like some information on BOG antennas:
I have 3 beverage on the ground antennas now. They are made of soft drawn
enamel copper wire, each one is about 500-700 feet long. I have terminated
each one with a 200 ohm resistor against a short copper ground rod. I am
matching them with an ICE transformer using the 300 ohm tap. I remotely
switch them with a relay box and they are fed to the shack with standard 50
ohm coax, about 150 feet long. I built the KD9SV variable gain preamp which
I have in the shack and can switch from 160 meters to 80 meters.
I also have, 3 above ground beverage antennas which I can use to compare.
Note that none of these antennas have been either cut, or tuned to the
perfect cone of silence length.
So far, at no time have the on the ground beverages performed better then
the above ground beverages. However, I think the main problem is the
preamp, being located in the shack is not optimal because I am amplifying
the line noise as well as the signal. When the signals are strong enough,
especially on 80 meters I have noticed that on some occasions, the on the
ground beverage shows better signal to noise (just less output).
My plan, is to try and find a suitable preamp to locate remotely at the feet
point of the beverage. However, I do have a problem with IMD, harmonics and
overload, from the nearby BC station (I live on "Signal Hill"!). Therefore,
I wonder if anyone can suggest a good preamp which would be suitable for
this application. I am also building the W3LPL hi-pass filters for both 160
and 80 meters which I plan to locate ahead of the preamp. Also, I plan on
replacing the single copper wires with 300 or 450 ohm twinlead and, using
terminating transformers have a two wire beverage setup.
Because my location does not provide for lots of conventional above ground
antennas, [these are all stealth antennas located on public land] I am quite
keen on trying to optimize the on the ground setup.
I would greatly appreciate help or advice from anyone regarding a suitable
preamp, what kind of matching impedance is likely to be correct, and how to
tune for the cone of silence length. Also, I am hopeful that maybe someone
else out there, has some firsthand experience with these low output
antennas. I think, that this type of setup could prove to be an answer for
those of us who have to take the stealth antenna approach.
I do have the two most recent editions ON4UN's book lowband DXing and it is
dog eard from use.
73, de Steve, VE6WZ.
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