On 10/31/20 12:11 PM, kq2m@kq2m.com wrote:
I want to thank KK9A, NA6O, W4EF, SM2EKM, DCharing (callsign?) and W6RMK, for
all of their guidance, comments and links to helpful sites. Greatly
appreciated as always!
Now for the final question... let’s say that the “positions” of the Gauge 12 or 14
THHN wire 4-square elements are N, E, S, and W, arranged in a box with the sides broadside to NE, SE, SW,
and NW and all the elements will all have either 3 or 4 elevated radials. I will be using the Comtek ACB4
(80) phasing box fed with each element fed with 1/4 wavelengths of RG11 foam coax. (It’s the same
phasing box I have been using for the past 25 years).
Does it matter what directions the radials are pointing for each element?
Not really - what the radial(s) do is provide a return path for the
current that "intercepts" the ground - and reduce "ground loss"
(independent of the "counterpoise" function).
The elements themselves are assumed omni directional. And it's only some
some sort of extreme cases (1 radial) that there's a more than trivial
effect on the directionality of the radiation pattern of a single
element. What changes is the efficiency (i.e. the loss resistance gets
lower as the number of radials increases).
In the usual 4SQ "current forcing" array with 3/4 wavelength feed lines,
the current in the element (which is what radiates) is the right
ampliude and phase to form the beam.
So let’s say I am using the NE position on the ACB-4 controller, since I
am radiating on all 4 elements, does it matter what directions the
radials are pointing? Do I want to have the same radial directions with
all 4 elements or do I want to spread out the radial directions
differently on each element? Since NE is by far the most important
direction for me (Europe), do I want to have more radials pointing NE or
broadside NE or equally spread out so that the radiation and current
return is more uniform? I am not clear on any of this or if it is even
important so I would appreciate any guidance that you can provide!
My understanding is that I want to get the radials at least .05 wavelength above
ground so at least 13’ above ground. Is that correct?
Tnx & 73
Bob, KQ2M
-----Original Message-----
From: jimlux
Sent: Friday, October 23, 2020 8:44 AM
To: towertalk@contesting.com
Subject: Re: [TowerTalk] 4 square question
On 10/22/20 9:45 PM, Michael Tope wrote:
Bob,
I found this by googling "4 square 8 directions":
https://ncjweb.com/bonus-content/k3lc4squarea.pdf
I think W8JI describes something similar on his website.
73, Mike W4EF....................
and that 4 square handbook from the DF6QV.. He's got all possible boxes
and phasing
http://tm1o.free.fr/4SQ/80m/en_ver_final4-sq_03_04_15.pdf
On 10/22/2020 7:39 PM, kq2m@kq2m.com wrote:
I really want to thank Jim, Jeff, Les, Mike, John and Gary for all of
their help, answers and ideas to which I have been giving a lot of
thought this week. The information gleaned has made me confident of
the new design. Unfortunately there is no way to avoid putting the
4-square elements around the tower so I know that interaction effects
will likely be noticed. Vicious storms have taken down all the other
tall trees that were previously in use to support my 80 meter 4-square.
Note to Jim Lux – I am particularly intrigued by your idea of changing
the feeding of the elements so that I can radiate broadside from the
side of the array rather than on the diagonal since the only trees
that I have to support elements happen to be roughly N, E, S and West,
which, with the Comtek phasing box, would give me radiation N, E, S
and West rather than the desired NE, SE, SW and NW.
The Comtek ACB-4 outdoor box uses the NW element in Pos 1 on the
outdoor , NE (2), SE (3) and SW in position 4 and arranged as shown in
the .pdf:
www.static.dxengineering.com/pdf/comtek_4_square_info.pdf
Which elements (N, E, S, W) would you put in which positions on the
box (so that the 4-square radiates toward the NE instead of East?
How is the gain and F/B and F/S compared to the standard pattern that
radiates diagonally?
Tnx to all & 73!
Bob KQ2MTowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
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