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 <[email protected]> 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 <[email protected]> >> 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
