Andy
I did a lot of experiments about two years ago with LOGs and BOGs.
Generally I found the BOG to be better and a smaller investment in
"wire". I did a lot of experiments with feeding the LOGs in different
locations (sides, corners, etc) and the results we never very
outstanding. Now I was not as religious about having the LOG actual
laying on bare earth everywhere ( see next paragraph) since I was not
aware at the time that actual laying on top of the ground might be
better for this family of antennas.
My other observation is that for best F/B and RDF is that unlike it s
big brother the BEVERAGE that shorter is better for the BOG. In my case
I have very poor soil (.001/5) . 6" down it pure white sand it ever
stops raining here in Florida for a year it will become a large sand
dune. In my case extensive modeling with AutoEZ and EZENEC PRO4/Ver6.
suggest that optimum F/B @20 degrees arrival is obtained at at about 225
feet (68 meters) and optimum RDF is obtained at ~275ft ( 84M) . I then
ran the same analysis with better soil conductivity and optimum BOG
lengths were even shorter! This is likely the reason that some folks
report that the BOG is a reasonably good performer and for others find
it is useless.
Now as a matter of full disclosure, all my BOGS are bi-directional with
reflection transformers at the ends and made from RG6, so the actual
antenna (not just the feedline) is a bigger conductor than a "wire" I
also noted in both theory and in practice that elevation above actual
earth of even a few inches destroyed the F/B. I have since gone to great
pains to get my BOGS "touching" the bare sandy earth . Those of you with
real dirt and or grass may have a different experience !!
Dave
NR1DX
On 1/7/2022 3:06 AM, Andree DL8LAS via Topband wrote:
Hey gentlemen,another test with a new RX antenna here at my QTH.Weather was
fine yesterday, so I built a LOG.Size 30m x 30 x 30 x 30,
direction 315/125.First test this morning was not bad , compared to my 180m
long beverage to USA.The LOG is a little bit more noisy, but for a simple wire
absolutely ok.If you are interested, here is a video from the QSO N1PGA
whileswitching the RX antennas.
https://www.youtube.com/watch?v=IA2IZeG0LpU
73 , Andy DL8LAS
www.dl8las.com
www.swing-company-bigband.de/
www.uni-big-band-kiel.de/
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