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## Re: [TowerTalk] H frame for 10 or 15m

 To: "Jay Kesterson K0GU" , towertalk@contesting.com Re: [TowerTalk] H frame for 10 or 15m "Brobakken, LA6FJA K3RAG" Tue, 16 Aug 2011 04:30:00 +0200 mailto:towertalk@contesting.com>
 ```THANKS FOR NICE MODELLING! >From my HTC, LA6FJA ----- Reply message ----- Fra: "Jay Kesterson K0GU" Dato: tir., aug. 16, 2011 03:36 Emne: [TowerTalk] H frame for 10 or 15m Til: On 8/15/2011 1:30 PM, Stein Roar LA6FJA-K3RAG wrote: > Hi > > does anyone have ideas sizes for a H frame for 4-5 el yagies for 10 m and 15m > ? > is it 1/2 wl , 3/4 wl or 1 wl spacing ?? > > I saw one from http://www.arraysolutions.com/Users/h2a.jpg Arraysollution > from PY5EG > > > 73 LA6FJA Rag Your best bet if possible is to model the antennas and look at the gain compared to one antenna and the patterns. The wider the horizontal spacing the bigger your first side lobes. That may not be a problem if you can't stack them very far apart horizontally. But if you can stack them far apart then you need to possibly chose a bit more gain vs a better pattern. I have a model of a Hy-Gain 105CA (24' boom) for my antenna modeling program. And I am a bit bored so here goes... Just to get the feel for how the horizontal and vertical stacking distance affects the antenna I first model only two antennas. Single 105CA = 8.24 dbd Two 105CAs stacked vertically spaced 20 feet = 10.50 dbd 24 feet = 10.84 dbd 28 feet = 11.12 dbd 32 feet = 11.30 dbd 36 feet = 11.35 dbd As far as vertical spacing is concerned somewhere around 24-28 feet looks pretty good. There is less interaction between the antennas as the stacking distance gets larger. More than 28 feet produces little advantage and a fair amount of extra wind load.. Two 105CAs stacked horizontally spaced 20 feet = 9.72 dbd (first side lobes are ~37 db down) 24 feet = 10.27 dbd (first side lobes are ~30 db down) 28 feet = 10.66 dbd (first side lobes are ~22 db down) 32 feet = 10.95 dbd (first side lobes are ~16 db down) 36 feet = 11.11dbd (first side lobes are ~16 db down) This will depend on how much you value gain compared to pattern. I would likely choose 28 feet vertically and 24 or 28 feet horizontally. I like a nice tight pattern. Not a lot of advantage beyond 28 feet. 4x H-Frame array of 105CAs spaced 20' high - 20' wide = 12.00 dbd 20' high - 24' wide = 12.46 dbd 24' high - 24' wide = 12.71 dbd 28' high - 24' wide = 13.09 dbd 28' high - 28' wide = 13.53 dbd The first azimuth side lobes are essentially the same value on the 4 stack as the 2 horizontal stack. This model is based on a 24 foot boom 10m yagi. A shorter boom will require a bit less spacing and a longer boom more spacing. 73, Jay K0GU _______________________________________________ _______________________________________________ TowerTalk mailing list TowerTalk@contesting.com http://lists.contesting.com/mailman/listinfo/towertalk ```
 Current Thread Re: [TowerTalk] H frame for 10 or 15m, s-roabr@online.no Re: [TowerTalk] H frame for 10 or 15m, Brobakken, LA6FJA K3RAG <= Re: [TowerTalk] H frame for 10 or 15m, Pete Smith Re: [TowerTalk] H frame for 10 or 15m, Joe Subich, W4TV Re: [TowerTalk] H frame for 10 or 15m, Jay Kesterson K0GU Re: [TowerTalk] H frame for 10 or 15m, Joe Subich, W4TV Re: [TowerTalk] H frame for 10 or 15m, W5PR Re: [TowerTalk] H frame for 10 or 15m, Jay Kesterson K0GU Re: [TowerTalk] H frame for 10 or 15m, W5PR Re: [TowerTalk] H frame for 10 or 15m, Jay Kesterson K0GU [TowerTalk] Modeling over ground was: Re: H frame for 10 or 15m, Pete Smith Re: [TowerTalk] Modeling over ground was: Re: H frame for 10 or 15m, Jim Brown