This is one way to look at it. The other way to look at it is that a higher gain antenna would have a much larger more focused lobe in the required direction. This would spread much less signal in directions that were not desired. The worst offenders at this are sector and omni antennas. This also inherently makes the link more secure since someone would have to be with in a few degrees of the radiating antenna to sniff. Go for the 24dBi uni's. If the signal is to hot try some pads, but chances are that your radios AGC will cope.
Less gain usually means less focus and that will end up tossing out more noise in more directions. Who are we kidding? When we talk about using ghetto antenna vendors and WAP11's isn't that bad RF design practice? Dan. On Tue, Jul 01, 2003 at 05:17:05PM -0700, Patrick Leary wrote: > Your antennas are horrendous overkill for the application. Those are the > sort of antennas you use to go 15 or many more miles, NOT 400 meters. What > you are doing is tossing noise out many miles beyond and it is considered > very poor RF design practices. This is not a slam, it is just something to > learn and the person that sold you the antenna should have known better. You > should replace the antennas with a small 8dBi at most. > > Regards, > > Patrick Leary > > -----Original Message----- > From: Loren Zemenick [mailto:[EMAIL PROTECTED] > Sent: Tuesday, July 01, 2003 8:09 PM > To: [EMAIL PROTECTED]; [EMAIL PROTECTED] > Subject: RE: [BAWUG] A few little trees - wheres my saw gone > > > 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 > > > 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 -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
