On 10/18/20 11:49 AM, kq2m@kq2m.com wrote:
Hi,
I will be rebuilding several 4-squares this season as well as restringing them
in different trees due to Tornado damage (loss or destruction of many trees at
my qth) during Tropical Storm Isaias on August 4th. I have a few questions for
which I would appreciate your guidance....
1) If I recall correctly, for purposes of focusing on Europe, ideally I would
want to put the 4 elements in a box formation in the NE, SE, SW and NW
directions relative to the middle of the array. Is that correct?
That's an interesting question - phased arrays with small numbers of
elements are really more of "reduce the wrong way" than "enhance the
right way"
You kind of want to look at what directions you want to radiate to, or
to suppress and figure it out that way.
An interesting thought that just occurred to me is that one could
conceivably arrange 4 elements in a variety of ways, and optimize the
various switched directions. Sort of like using HFTA to figure out
antenna heights on a tower.
2) In the 4-square when I select the controller direction NE, I am effectively
radiating broadside NE from the NW and SE elements. Is that correct?
Direction is correct, but all 4 elements are contributing to the
radiated signal.
A better way to think about 4 squares is that you are reducing the
signal in unwanted directions - the beam is still fairly broad, but if
properly set up, you get a significant reduction behind.
And, with all 4 radiating in the horizontal plane, the vertical
beamwidth is narrower. A single vertical has a pretty broad vertical
beam. 4 radiating together squishes that down.
3) In the past I had the bottom of the 4-square elements soldered to center
conductor of the pin of an SO239 with the radials attached to each of the SO239
screw holes, with the coax connector for the phasing line screwed onto the
SO239. (The choke was located below the PL259 on the phasing line) This
worked well but I am trying to improve the design.
That sounds just fine as is.
If I were to terminate the bottom of the 4-square element by twisting it through and
around one hole of the porcelain insulator and soldering it there, would I still be
able to then solder a small wire from that connection to the center conductor pin of a
SO239 with the radials attached to the SO239 screw holes as before? My idea being
that I can do that then I can use a piece of twine through the remaining porcelain
insulator hole taped to the coax to provide additional physical support for the coax
and radials – which will be helpful during ice storms.
Why not..
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