Hi Rudy,
At my qth in Connecticut, I have and continue to use WIRE 4-squares with
ELEVATED radials on BOTH 40 and 80 at my qth since 1995. In that time I have
won the US in the SOABHP UNassisted category MULTIPLE times in these DX
contests: ARRLDX CW, ARRLDX SSB, CQWW SSB, WPXSSB, WPXCW, IARU, WAECW and
WAESSB. (I don’t even have a rotatable 40 meter beam!)
I tell you this because it would NOT have been able to consistently win these
this extremely competitive category in these extremely competitive DX contests
without the excellent performance of my 4-squares (which both use the Comtek
boxes).
In short, you are overthinking this. If your are pressed for time, use the WIRE
4-square design with ELEVATED radials and the antenna will perform VERY WELL!
Just make sure that you use thin twine (I use #16) to connect the feedpoint of
each element to the other elements – so that you form a SQUARE and then connect
the the two diagonal elements with the twine. This helps to maintain the exact
required spacing between the array elements.
If you measure the distance between each adjacent element properly as well as
each element diagonal across the square, and then connect just below each
feedpoint with twine, the the 4-square feedpoints will stay in alignment and
proper spacing regardless of the wx and you will get excellent F/B, and F/S
with good Forward gain at a low angle of radiation. Make sure to get the
elements and radials elevated at least 10’ for 80 meters – 15’ in height is
better.
Don’t be concerned if you can’t get the elements fully vertical – all four of
my elements are at least partly horizontal and the array is still VERY potent
in the contest and all of the crazy DXpedition pileups. When I have been on ,
there hasn’t been a major DXpedition that I haven’t worked on 80.
The formulas are simple – 246/f for element spacing and 234/f for the length of
each vertical elements. And 246/f x Vf for the lengths of the RG11 phasing
lines. For 3.5 mhz, I use either 9 Fair-rite 43 material FB-1020 beads or 7 of
the 77 material FB-1024 beads. (1” OD, 0.5” ID x 1 1/8” Height) for my chokes.
Aluminum will potentially give you wider bandwidth with lower SWR and dumped
power, but with my array cut and tuned for ~ 3.6 mhz, I can comfortably cover
3.5 – 3.75 mhz with no issues.
If I can win all the DX contests and easily break all the DX pileups on 80 with
the array that I described (while running LEGAL, not excess, power), then your
array will do very well too and you won’t have to wait until next year to enjoy
the results.
Once I have the ropes in the 4 trees, it takes me approximately 4 hours to
completely put up the 4 elements, set the spacing between the elements with the
twine and connect all 4 elements to each other, attach all 16 elevated radials,
tie them to trees and tension them, and check and angle of the array to ensure
that the 4 elements hang vertically just below the tree “connections” , and
loosen and re-tighten all elements as necessary. And then I can get on the
bands and work DX!
73
Bob KQ2M
From: Rudy Bakalov via TowerTalk
Sent: Monday, September 04, 2017 8:59 PM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] phased verticals again
Hi Kelly,
The big picture here is that I am optimizing not only for gain, F/B, etc. but
also for time. There are 684 very long miles between CT and my station in VE3.
So I always consider how long would it take to do this and that project and if
I will ever have the time to complete it.
The K8UR array was the very first option I considered. I ruled it out thinking
that it will take a long time to tune the dipoles.
So the elevated radials seem like a good shortcut. I really didn't feel like
clearing the bush and trees around the tower to lay the radials.
I also considered going with aluminum from the very beginning. A fairly
straightforward project. Again, didn't want to clear the forest to make room
for a standalone array so decided to use the tower and string the wires. I also
made the mistake to share my plans with my European friends who somehow managed
to talk me out of aluminum (it's quite expensive and not quite readily
available in telescoping sizes).
So this is how I ended up with wires and raised radials. For now I will keep
the wires, but lay ground radials. Perhaps will hire the kids to help :-).
Unfortunately I won't have the time to do so until next spring and VC3I will
have a mediocre 80 m antenna for CQ WW RTTY and CW. I hope it's at least as
good as the inv V at 90' I took down last week.
Rudy N2WQ
Sent using a tiny keyboard. Please excuse brevity, typos, or inappropriate
autocorrect.
> On Sep 4, 2017, at 8:25 PM, Kelly Taylor <ve4xt@mymts.net> wrote:
>
> Hi Rudy,
>
> Sounds like you have a conundrum!
>
> The vertical dipole idea may still have merit: the legs of the dipole need
> not be straight. Nor do T or L sections need to be perpendicular to the
> vertical elements.
>
> As mentioned, it removes the ground plane issue, it also moves the current
> maxima higher, which always helps.
>
> Could you, for instance, run catenaries from the top of the tower to
> insulators that would hold an end of each T-bar, then affix a vertical
> element down to a feedpoint, with the other side of the feedpoint dropping
> vertically to the 10 foot level where it would meet the lower T-bar?
>
> Folks have had success creating both vertical dipoles and vertical-dipole
> four squares using this idea, with towers similar to yours.
>
> Worth a thought?
>
> 73, kelly, ve4xt
>
> Sent from my iPhone
>
>> On Sep 4, 2017, at 18:20, Rudy Bakalov via TowerTalk
>> <towertalk@contesting.com> wrote:
>>
>> Well, it's an option, but you need the height for this arrangement. In the
>> case of 80, assuming you have the bottom of the dipole 10' from the ground,
>> you need a ~105' tower. What you are describing is the K8UR array.
>>
>> Rudy N2WQ
>>
>> Sent using a tiny keyboard. Please excuse brevity, typos, or inappropriate
>> autocorrect.
>>
>>
>>> On Sep 4, 2017, at 7:01 PM, Hans Hammarquist via TowerTalk
>>> <towertalk@contesting.com> wrote:
>>>
>>> Gentlemen,
>>>
>>> I wonder if it could be a good idea to use vertical dipoles instead of 1/4
>>> w verticals and groundplanes. That way you would do away with the
>>> groundplane (that seems to cause issues). My idea was to "hang" up four
>>> full size dipoles or maybe shorted such.
>>>
>>> Just a thought.
>>>
>>> 73 de,
>>>
>>> Hans N2JFS
>>> _______________________________________________
>>>
>>>
>>>
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>>
>> _______________________________________________
>>
>>
>>
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