Trees impact the link most when they hit you close to either end of the link. Your fresnel zone looks like a football pattern, so more of the energy is getting blocked when the obstruction blocks close to either end. You did not say what elevation you have at either end, but you need to go higher at the front end side of your link. You would be suprised what even another 10 feet can do in some cases.
Patrick -----Original Message----- From: Andy Barlak [mailto:[EMAIL PROTECTED] Sent: Tuesday, July 01, 2003 8:48 PM To: [EMAIL PROTECTED] Subject: RE: [BAWUG] A few little trees - wheres my saw gone Have a 4.4 mile link with major trees at 30 yards and 300yards, clear the rest of the way. Had the closest trees topped by 20 feet ($200) to get a clearer LOS, and by good fortune the neighbor topped his trees ($300) to clear the way at 300 yards. The end result was no perceptable improvement in the wap11 v2.2 wireless link with 24db dishes at each end. On Tue, 1 Jul 2003, Loren Zemenick wrote: > I have two links that penetrate trees, one about 400 meters and the other > about 800. The 400 meter link uses a pair of 18 dbi antennas. The 800 meter > link uses a 17 dbi and a 24 dbi. All links use Linksys WAP11's. The key > issues is the density of your folage. I would try it knowing if you can get > a single ping returned with the omni, a directional will give you a healthy > fade margin. > > Loren Zemenick > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of Richard Fennell > Sent: Tuesday, July 01, 2003 4:47 PM > To: [EMAIL PROTECTED] > Subject: [BAWUG] A few little trees - wheres my saw gone > > > ok chaps, im goin to ask a question that youve probably all heard before and > are fed up with answering. I currently have a high gain antenna on the top > of my employers building. about 15dB hyperlink directional grid. > > I have just moved to a house about 400 meters away (maybe less). On the side > of the house there is this great big 10 foot pole where the previous owner > used it for a TV antenna (Cable rocks tbh). > > So i have come up with the idea of putting an omni directional at the top of > this pole and seeing if i can link. > > Problem is the good ole LOS, i cant see my house because of trees and houses > and stuff from my employers roof. Is it not even worth bothering to attempt > to link the two or is there a chance that signal may either bounce or > penertrate. Also i might have LOS i just havent got a ladder long enough or > the the guts to go up and have a look, looks about 20-25 feet. > > Thanks > > Richy > > > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.495 / Virus Database: 294 - Release Date: 30/06/2003 > > -- > general wireless list, a bawug thing <http://www.bawug.org/> > [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless > > -- > general wireless list, a bawug thing <http://www.bawug.org/> > [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless > ---------------------------------------------------------------------------- --- Andy Barlak On my desk I have a work station. Trains stop at train stations. -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless This mail passed through mail.alvarion.com **************************************************************************** ******** This footnote confirms that this email message has been scanned by PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses. **************************************************************************** ******** -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
