Topband: 4SQ Arrays in proximity

[Jan Erik Holm]

I once was thinking about a deal like this. In my case I wanted
to put a 40m 4SQ inside my 80m 4SQ.
I did model it and saw a slight gain loss, think it was just
around 1 dB or so. I didn´t like that so I instead did put
the 40m 4SQ 300m/1000ft away from the 80m array. I´m sure
I could have bettered the situation by detune the 80m
antennas but I never did look in to that.
Gain loss was on the 40m array, the 80m didn´t get hurt.

/ Jim SM2EKM


Den 2020-01-28 kl. 17:43, skrev Mpridesti via Topband:
> I had heard several negative mentions of placing an 80 m system inside a 160 m 4 square.  At my place, I placed my 80 m 4 SQ northeast of my 160 m 4 SQ. Closest elements are 75 feet away. Thinking I might get some negative interaction, I took K3LR’s suggest of opening the feed points of the 80 m array while I am using 160. Built a relay box that shorted the cable ends (1/4 wave 75 ohm lines) so electrically opened the feed points. Pretty simple.
> 
> Then spent a lot of time listening to WebSDR receivers in EU and switched that relay box on/off to see if I saw any gain variation with the 160 antenna. I saw no difference. However I have found a very slight improvement in F/B or F/S when the 80 m array was open circuited (shorting relays engaged).
> 
> On the flip side of this, I have not seen any impact on 80 to the SW as I beam through the 160 array. I have reference antennas on each band to check array performance.
> 
> I continue to experiment on 160 - fun retirement project with lots of exercise!
> 
> Seems array interaction varies with different stations.  I did not model my setup.
> 
> Regards,
> 
> Mark, K1RX
> 
> 
>> On Jan 28, 2020, at 10:47 AM, Tree <tree at kkn.net> wrote:
>>
>> W7IV asks:
>>
>> " --I am planning a 160m TX 4SQ and another for 80M.   Their centers are
>> going to be about 300' apart - is this far enough away?  I have a little
>> bit of room to move them apart, but am lucky enough as it is to have the
>> space to get this.  The closest verticals will be about 200' apart."
>>
>> My experience supports the post K9YC just made that you don't need to worry
>> about this.
>>
>> I used to have an 80 meter 4 square with my 160 meter TX antenna right in
>> the middle of it and
>> everything worked great.  You can also see this in the ON4UN antenna
>> system.
>>
>> 73 Tree N6TR
>>
>>> On Tue, Jan 28, 2020 at 12:33 AM Paul F. Merrill <marinesvcs at gmail.com>
>>> wrote:
>>>
>>> HI - I have a couple questions -
>>>
>>> --I am planning a 160m TX 4SQ and another for 80M.   Their centers are
>>> going to be about 300' apart - is this far enough away?  I have a little
>>> bit of room to move them apart, but am lucky enough as it is to have the
>>> space to get this.  The closest verticals will be about 200' apart.
>>>
>>> --I'll be using N6BT vertical dipoles, so there will be no radial issues.
>>>
>>> --WRT TX chokes - I'm worried about constructing feedline chokes for the
>>> feedpoints and still having enough cable (.85vf) to get to the phasing
>>> box.  How have others done this?  Do you have a choke and did you add it to
>>> pre-cut phasing lines or did you wind the chokes and work backwards towards
>>> the center to get the required electrical or physical length?  Did you used
>>> magnet wire for the choke instead of coax?
>>>
>>> I've come across N6RO's helpful 2017 writeup of his 4SQ refurbishment and
>>> it touches on these issues.  Anyone else have time to share some wisdom?
>>>
>>> Thanks in advance, Paul / W7IV
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