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References: [ +subject:/^(?:^\s*(re|sv|fwd|fw)[\[\]\d]*[:>-]+\s*)*\[TowerTalk\]\s+Tree\s+attenuation\s*$/: 13 ]

Total 13 documents matching your query.

1. [TowerTalk] Tree attenuation (score: 1)
Author: K7LXC@aol.com
Date: Mon, 7 Nov 2005 13:28:34 EST
Howdy, TowerTalkians -- Here's an interesting PowerPoint presentation called Effects of Trees on Slant Propagation Paths that looks at signal attenuation thru trees. It generally covers VHF and above
/archives//html/Towertalk/2005-11/msg00240.html (6,894 bytes)

2. Re: [TowerTalk] Tree attenuation (score: 1)
Author: Jim Lux <jimlux@earthlink.net>
Date: Mon, 07 Nov 2005 12:15:59 -0800
There's a more complete version of this at Utexas.. http://www.utexas.edu/research/mopro/ In particular, you might be interested in Chapter 2 and 3 The summary is that at low angles, the attenuation
/archives//html/Towertalk/2005-11/msg00242.html (9,178 bytes)

3. Re: [TowerTalk] Tree attenuation (score: 1)
Author: "Jim Brown" <jim@audiosystemsgroup.com>
Date: Mon, 07 Nov 2005 15:24:28 -0600
I skimmed both the Power Point and the longer document. The analysis that went into the Power Point make it considerably more valuable in guestimating what might happen at VHF and low UHF, but neithe
/archives//html/Towertalk/2005-11/msg00243.html (7,993 bytes)

4. Re: [TowerTalk] Tree attenuation (score: 1)
Author: Jim Lux <jimlux@earthlink.net>
Date: Mon, 07 Nov 2005 14:12:53 -0800
The short answer is no. There's not much research interest in HF frequencies at least as far as propagation through forests. People who have serious money to spend on HF antenna installations where l
/archives//html/Towertalk/2005-11/msg00244.html (9,221 bytes)

5. Re: [TowerTalk] Tree attenuation (score: 1)
Author: Jim Lux <jimlux@earthlink.net>
Date: Mon, 07 Nov 2005 14:37:19 -0800
The paper you want is by Theodore Tamir, "On Radio-Wave Propagation in Forest Environments", IEEE Trans on Ant and Prop, Vol AP-15, #6, Nov 1967, pp 806-817 He covers 1-100 MHz, and lots of experimen
/archives//html/Towertalk/2005-11/msg00245.html (11,156 bytes)

6. Re: [TowerTalk] Tree attenuation (score: 1)
Author: "Frederick M. Mott" <ab8ah@earthlink.net>
Date: Mon, 7 Nov 2005 19:20:39 -0500
I operated a MARS station (AB8AH - 1st Bde 1st Inf Div) in Phouc Vinh than in Quan Loi, Viet Nam during 1967 and 1968. There were no trees at both locations near our towers (100 ft Rohn 25G and a 70
/archives//html/Towertalk/2005-11/msg00253.html (11,165 bytes)

7. Re: [TowerTalk] Tree attenuation (score: 1)
Author: "Tom Rauch" <w8ji@contesting.com>
Date: Mon, 7 Nov 2005 19:28:52 -0500
Phouc Vinh than trees at both commercial tower) tree). Our site phone patches a month. located in a rubber beam was suspended patches a month. Hi Fred, Respectfully, there are far too many variables
/archives//html/Towertalk/2005-11/msg00254.html (9,545 bytes)

8. Re: [TowerTalk] Tree attenuation (score: 1)
Author: Cqtestk4xs@aol.com
Date: Mon, 7 Nov 2005 19:45:46 EST
Everything I have observed is trees make very little difference at lower HF. My last house had vertical antennas nestled in trees, and everything appeared to work as well as any other stations in pil
/archives//html/Towertalk/2005-11/msg00255.html (8,436 bytes)

9. Re: [TowerTalk] Tree attenuation (score: 1)
Author: Jim Lux <jimlux@earthlink.net>
Date: Mon, 07 Nov 2005 16:49:16 -0800
It is precisely the sort of thing you observed 40 years ago that prompted the research of George Hagn at SRI (and others, like Tamir) on propagation through or around forests and jungles. They went o
/archives//html/Towertalk/2005-11/msg00256.html (11,934 bytes)

10. Re: [TowerTalk] Tree attenuation (score: 1)
Author: Jim Lux <jimlux@earthlink.net>
Date: Mon, 07 Nov 2005 17:45:08 -0800
Which is what the folks did for the research. At HF, especially on low bands (40 and below), it seems you're probably looking at a maximum few dB difference because of the trees, and as you note, the
/archives//html/Towertalk/2005-11/msg00259.html (10,038 bytes)

11. Re: [TowerTalk] Tree attenuation (score: 1)
Author: Jim Lux <jimlux@earthlink.net>
Date: Mon, 07 Nov 2005 17:46:19 -0800
That's actually been quantified, at least for the VHF and up frequencies.. The U Texas report has a whole part of chapter 2 that discusses the effects of foliage presence and seasonal variations. ___
/archives//html/Towertalk/2005-11/msg00260.html (9,322 bytes)

12. Re: [TowerTalk] Tree attenuation (score: 1)
Author: "Marlon K. Schafer (509) 982-2181" <ooe@odessaoffice.com>
Date: Tue, 8 Nov 2005 07:57:30 -0800
Anyone know where we can get our hands on that research? thanks, Marlon (509) 982-2181 Equipment sales (408) 907-6910 (Vonage) Consulting services 42846865 (icq) And I run my own wisp! 64.146.146.12
/archives//html/Towertalk/2005-11/msg00268.html (14,656 bytes)

13. Re: [TowerTalk] Tree attenuation (score: 1)
Author: Jim Lux <jimlux@earthlink.net>
Date: Tue, 08 Nov 2005 09:26:41 -0800
Which research in particular? The older stuff tends to be published in places like IEEE Transactions on Antennas and Propagation, and sometimes in Radio Science. Newer things, particularly when it's
/archives//html/Towertalk/2005-11/msg00274.html (18,246 bytes)

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