[TowerTalk] 4 square question Part III

[jimlux]

On 10/31/20 12:11 PM, kq2m at 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 at 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 at 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 at contesting.com
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