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@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@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
>> _________________
>> Searchable Archives: http://www.contesting.com/_topband - Topband
>> Reflector
>>
> _________________
> Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
_________________
Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
|