[TowerTalk] Beverage Antenna

Joe Subich, W4TV lists at subich.com
Tue Feb 3 18:10:17 EST 2015


Grant,

Thanks for the modelling and the insulator idea.  I'd suspect one
might be able to tweak the lengths between insulators to find a
"non-resonant" length on both 160/80 to minimize the impact of a
multi-strand barbed wire fence but as you suggest chain link or
welded mesh ("hogwire") fences could be an issue.

In my case, I'm looking at a variation of KB7GF's "cross-coupled
shared apex array loop" that will fit in a 100' diameter circle
with performance comparable to a 1000' Beverage and 60 degree
switching.  Building it is probably next fall's project since I
have a wooded area that would hide it nicely.

73,

    ... Joe, W4TV


On 2015-02-03 5:11 PM, Grant Saviers wrote:
> I did a quick EZNEC Pro/4 analysis of a Beverage over a 3 strand barb
> wire fence, strands at 4,3,2' and antenna at 10'.  I've had one that
> sorta worked, now I know why.
>
> 600' of fence under 600' of antenna yields a substantially degraded F/B
> (what I experienced).
>
> 2400' of fence under 600' of antenna yields a substantially vertical
> pattern
>
> Insulator breaks of the 600' of the 3 strands every 200' yielded a
> 1.8Mhz pattern almost the same as no fence.  Adding a single strand of
> continuous single fence out 600 to 1200' past both ends of the Beverage
> had minimal pattern change.  At 3.5 and 7 Mhz the pattern looses a bit
> of F/B but is tolerable IMO.
>
> So for a few insulators, a Beverage works over a barb wire fence.
> Porcelain eggs would probably be the best bet for the strength needed.
>
> Chain link and welded mesh fences are best avoided unless it is worth
> the work to insulate sections.
>
> Grant KZ1W
>
> On 2/3/2015 12:52 PM, Joe Subich, W4TV wrote:
>>
>> Pat,
>>
>> 8 to 10 feet above the barbed wire fence would be your only chance if
>> you are to use the existing fence lines.  I would strongly suggest
>> reading some (all) of the references you have been offered -
>> particularly those that include long term experiments.
>>
>> My information has simply been gathered from the reports of others over
>> nearly 40 years and confirmed by the performance of the few simple
>> Beverages I've been fortunate enough to use at various times.
>>
>> The general consensus has been not to use a "ground wire" under a
>> Beverage or run it along above/parallel to a conductive wire fence.
>> Maintain at least 45 degrees and try, if at all possible, to cross
>> other antennas/conductive objects at right angles.
>>
> snip...
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