- 1. [TowerTalk] Tribander Spacing (score: 1)
- Author: "Keith Dutson" <kdutson@sbcglobal.net>
- Date: Fri, 20 Feb 2015 14:36:24 -0600
- I have a F-12 C3 up at 120 feet. I want to add a second C-2. What would you recommend for spacing? QTH is Houston, TX area. Thanks. 73, Keith NM5G _______________________________________________ ____
- /archives//html/Towertalk/2015-02/msg00369.html (6,518 bytes)
- 2. Re: [TowerTalk] Tribander Spacing (score: 1)
- Author: Pete Smith N4ZR <n4zr@contesting.com>
- Date: Fri, 20 Feb 2015 15:56:32 -0500
- Assuming you meant a second C-3, I did extensive modeling of pairs of C-3s back in the late 90's when I put my stack up. There was an NCJ article, but if you like I can try to dig up the manuscript h
- /archives//html/Towertalk/2015-02/msg00370.html (8,373 bytes)
- 3. Re: [TowerTalk] Tribander Spacing (score: 1)
- Author: David Gilbert <xdavid@cis-broadband.com>
- Date: Fri, 20 Feb 2015 17:40:20 -0700
- HFTA is a poor judge of spacing. There is a known flaw in the model, and it will overstate the stacked gain for narrow spacings. 73, Dave AB7E I wound up with C-3Es at 97 and 69 feet. It's too wide f
- /archives//html/Towertalk/2015-02/msg00373.html (9,083 bytes)
- 4. Re: [TowerTalk] Tribander Spacing (score: 1)
- Author: Bill via TowerTalk <towertalk@contesting.com>
- Date: Fri, 20 Feb 2015 21:54:31 -0500
- Agreed it runs into trouble with spacings less than .5 wavelength. However, I have found that performance in the real world seems to be on the money for spacings greater than .5. Bill K4XS In a messa
- /archives//html/Towertalk/2015-02/msg00374.html (10,094 bytes)
- 5. Re: [TowerTalk] Tribander Spacing (score: 1)
- Author: Jim Lux <jimlux@earthlink.net>
- Date: Fri, 20 Feb 2015 19:34:00 -0800
- when you get closer than half a wavelength (maybe even farther if the Yagi is particularly high directivity), then the near fields of the two antennas interact, which HFTA does not model. NEC is you
- /archives//html/Towertalk/2015-02/msg00375.html (7,546 bytes)
- 6. Re: [TowerTalk] Tribander Spacing (score: 1)
- Author: "Keith Dutson" <kdutson@sbcglobal.net>
- Date: Fri, 20 Feb 2015 22:26:59 -0600
- Thanks Pete. Your spacing is only 28 feet, less than a half wavelength on 20. I also had a recommendation of 5/8 wavelength on 20. That calculates to 41 feet. I was thinking 35 feet. Guess I need to
- /archives//html/Towertalk/2015-02/msg00376.html (10,262 bytes)
- 7. Re: [TowerTalk] Tribander Spacing (score: 1)
- Author: "Joe Subich, W4TV" <lists@subich.com>
- Date: Fri, 20 Feb 2015 23:40:11 -0500
- Do a sanity check by modeling in EZNEC, 4NEC, etc. over flat earth. HFTA uses point (isotropic) sources and ignores coupling. HFTA will show more ground reflection than is actually present with real
- /archives//html/Towertalk/2015-02/msg00377.html (10,782 bytes)
- 8. Re: [TowerTalk] Tribander Spacing (score: 1)
- Author: <john@kk9a.com>
- Date: Sat, 21 Feb 2015 13:41:51 -0500
- I have never modeled tribanders but most of my monobanders have around 1 wavelength spacing. 28 foot spacing on 10m is not too wide in my opinion. John KK9A I wound up with C-3Es at 97 and 69 feet. I
- /archives//html/Towertalk/2015-02/msg00378.html (8,430 bytes)
- 9. Re: [TowerTalk] Tribander Spacing (score: 1)
- Author: Bill via TowerTalk <towertalk@contesting.com>
- Date: Sat, 21 Feb 2015 14:09:01 -0500
- Of the general rule of thumb is, shorter booms can have smaller spacing, to a point. Larger longer booms require more spacing than short booms. 28 foot spacing works quite well for 6/7 elements. At l
- /archives//html/Towertalk/2015-02/msg00380.html (9,642 bytes)
- 10. [TowerTalk] Tribander Spacing (score: 1)
- Author: "Jim Thomson" <jim.thom@telus.net>
- Date: Sat, 21 Feb 2015 19:25:18 -0800
- Thanks Pete. Your spacing is only 28 feet, less than a half wavelength on 20. I also had a recommendation of 5/8 wavelength on 20. That calculates to 41 feet. I was thinking 35 feet. Guess I need to
- /archives//html/Towertalk/2015-02/msg00389.html (8,566 bytes)
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