Modeling of Milt N5IA 160 8 circle with his 80M 4SQ out side showed same thing
- need to leave the 80 M elements open
Hank K7HP
----- On Jan 28, 2020, at 9:43 AM, Mpridesti via Topband
<topband@contesting.com> wrote:
| 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
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