Topband: Beverage Length vs F/B or (RDF?)
Artek Manuals
Manuals at ArtekManuals.com
Fri Oct 18 09:53:17 EDT 2019
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 at 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
>>>
>>>
>>>
>>> _________________
>>> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
>> --
>> Dave
>> Manuals at ArtekManuals.com
>> www.ArtekManuals.com
>>
>>
>> --
>> This email has been checked for viruses by Avast antivirus software.
>> https://www.avast.com/antivirus
>>
>> _________________
>> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
--
Dave
Manuals at ArtekManuals.com
www.ArtekManuals.com
--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
More information about the Topband
mailing list