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Re: [TowerTalk] Half-Square or ?? For 80m

 To: , "TowerTalk" Re: [TowerTalk] Half-Square or ?? For 80m "Jim Lux" Sat, 30 Oct 2004 16:39:54 -0700
 ```Why not feed all of dipoles as a phased array? Providing the direction you want to point isn't off the end of the dipole, then that dipole can contribute to the pattern. Sure, you won't be able to use some trivial phasing like 90 degrees, but it might repay a bit of fiddling with any of a number of antenna modeling programs just to see what might work. Programs like 4nec2 can be set up with current sources and symbols for the relative phases, then can do an optimizing for forward gain, or F/B, or nullling interference, or whatever. You'll want something like this at the end of your NEC deck( I've used 4nec2 syntax for the symbols). 901..904 are the feedpoints for the 4 antennas.: SY P1=0 ' initial phases SY P2= 100 SY P3= 200 SY P4= 300 EX 6 901 1 00 cos(P1) sin(P1) EX 6 902 1 00 cos(P2) sin(P2) EX 6 903 1 00 cos(P3) sin(P3) EX 6 904 1 00 cos(P4) sin(P4) Once you've figured out if you can get a pattern like you want, then, you can look at the feedpoint impedances and design a set of LC networks to generate just those phases. If you can decide on just a few dominant directions (and the dipoles alone for other directions), then you don't need many different networks. ----- Original Message ----- From: "Paul B. Peters, VE7AVV" To: "TowerTalk" Sent: Saturday, October 30, 2004 12:06 PM Subject: [TowerTalk] Half-Square or ?? For 80m I just had my tree climber back to the acreage and now have two new antenna supports at 110 feet. The two trees are 130 feet apart. Given the lay of the land, the new supports are on a north - south alignment -- not ideal, but I can't find a method of rotating the land just yet. I'm looking for suggestions on what might give a little additional gain over the two existing dipoles I already have in place. The dipoles are at 110 feet and they are at right angles to one another -- so one for lp/sp and the other for JA and NA. I have been considering a half-square for the new space -- it will just fit nicely with the horizontal 1/2 wave section at 123 feet for operation on 75m. As I continue to do my research, I wonder what other suggestions list members might offer me. Thanks in advance for any and all suggestions. 73 de Paul, VE7AVV StoneyGround Station -|<*><*>||<*><*>||<*><*>||<*><*>||<*><*>||<*><*>||<*><*>||<*><*>|- "All email from this address is checked by Norton AntiVirus 2003" _______________________________________________ See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA. _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk _______________________________________________ See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions and ask for Sherman, W2FLA. _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
 Current Thread [TowerTalk] Half-Square or ?? For 80m, Paul B. Peters, VE7AVV Re: [TowerTalk] Half-Square or ?? For 80m, Jim Lux <=