Jim
Poor front to back can indeed be a result of being too long. Although
w8JI would argue that at 700 feet your just about at optimum (1.5
wavelengths) I would think it would be easy to add an insulator /jumper
and a set of terminations and grounds at ~500 feet and see what the
difference is.
What kind of grounds do you have at the ends? Living on a granular
quartz plane myself with very poor ground conductivity ( I can push a
5ft length of 1/2" copper pipe 3ft in the ground by hand (pure sand!)
and easily tap it in the last two feet with a hammer) I would think
that the grounds at the end would indeed have an effect on front to back
or RDF which is the latest popular figure of merit ( how do you actually
MESAURE RDF?).
I often wonder how one knows when one has a "good enough ground". I have
read https://www.w8ji.com/beverages.htm many times. Tom suggest a proxy
method using temporary radials which I don't have the topography to
install in a meaningful way. The net result is I take Tom's
measurements with a grain of salt since they are done on soil with much
better conductivity than you (apparently ) or I have
Dave
NR1DX
On 10/18/2019 8:51 AM, MU 4CX250B wrote:
On this general subject, I’m using bi-diectional beverages 720 ft
long, suspended 7 ft above sandy desert ground. The F/B ratio is poor
(not important for New Mexico) but I’m wondering if the antennas are
too long? I use them on 80m/160m.
73,
Jim w8zr
Sent from my iPhone
On Oct 17, 2019, at 9:31 PM, Artek Manuals <Manuals@artekmanuals.com> wrote:
Tim
Which antenna will you be using ; BOG, Beverage or a FLAG/Pennant
I have been doing some experimenting with the BF-4X with BOGs and Beverages in both very poor sandy
soil and then again at a water front (salt) canal location. Eventually I will get around to trying
out a FLAG/Pennant style as well. Seems to work pretty well in my dry sandy location� the
performance has been less than stellar so far next to the saltwater canal, I think this may have
more to do with the seawall near by. This is a BOG issue and not any problem with the BF-4X boxes.
with BOGS i tried it in an end fed and center� fed configuration� and an of center
feed with a beverage.
The for BF-4X literature says BOGs from 100 to 300' . For my poor soil conditions
I find that 200' ( as many other s have reported for BOGs) is the upper limit>
performance was noticeably poorer at 225', 250' and 350' . This is a function of
soil conditions and not the boxes and YMMV.
Dave
NR1Dx
On 10/16/2019 11:35 AM, Tim Duffy wrote:
Thinking about the Fall Stew coming up this Saturday, I will be trying out
the BevFlex-4X that W9XT is now manufacturing.
Here is the flyer:
<https://static.dxengineering.com/global/images/technicalarticles/ums-bevfle
x-4x.pdf>
https://static.dxengineering.com/global/images/technicalarticles/ums-bevflex
-4x.pdf
And the BevFlex-4X details:
<https://www.dxengineering.com/parts/ums-bevflex-4x>
https://www.dxengineering.com/parts/ums-bevflex-4x
73
Tim K3LR
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