And how high are the sea walls you are attached to? JH ----- Original Message ----- From: "Oliver Leamy" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Wednesday, June 11, 2003 3:58 PM Subject: RE: [smartBridges] Height of Mast?
> Hi, > > Thanks for the replies. One thing I like about this Smartbridges e-mail > group is that when you ask a question you get answers!! > > You mentioned that the antenna I was using was an overkill, yet I was > only getting about 20%-40% signal strength on the SB air monitor program > and very poor throughput. When I used a 19dbi panel, I couldn't get any > connection at all !!!! > > I asked a related question today where I outlined the type of testing I > was doing. It was a temporary test so one link was at ground level and > maybe that is why it didn't work too well. I had a look at YDI and it > calculated a fresnel radius of about 45 feet. From that would I be > right in assuming that, for best results, each antenna should be at > least 45 feet above sea level. > > Oliver Leamy > > Ogenek Teoranta, Ballingeary, Macroom County Cork > +353 (26) 47808 ; +353 (86) 8337664 > > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On Behalf Of > [EMAIL PROTECTED] > Sent: 11 June 2003 23:26 > To: [EMAIL PROTECTED] > Subject: Re: [smartBridges] Height of Mast? > > fresnel incursion over water? (I'm assuming he's shooting over water > since > he's linking islands). > > I'd think it'd be more likely to be multipath from reflections off the > water. > > Try shooting horizontal instead of vertical. And did you say the islands > are only a few miles apart? If so, the 20dB is overkill. Use something > smaller or throttle the power back. (this will help minimize multipath > .or so I've read on the Internet ...and you can't trust the Internet ;) > > TIM > > ---------- Original Message ---------------------------------- > From: "John Hokenson" <[EMAIL PROTECTED]> > Reply-To: [EMAIL PROTECTED] > Date: Wed, 11 Jun 2003 15:30:47 -0700 > > >You have to be aware of fresnal zone incursion. I suspect that is why > you are seeing poor performance on your current link. Go to the > calculators on the YDI site and run the numbers. > > > >JH > > ----- Original Message ----- > > From: Oliver Leamy > > To: [EMAIL PROTECTED] > > Sent: Wednesday, June 11, 2003 1:21 PM > > Subject: [smartBridges] Height of Mast? > > > > > > > > Hi, > > > > > > > > I have a need to connect three islands together. Am going to use > AirPoints and 20.5dbi mesh antennas. On recent email discussions I've > noticed that most people are using masts and the antennas at 100 or 200 > feet. For our installations, we will have to use residential premises. > There is a clear view between the locations. > > > > > > > > Is there a reason why people were using 100' masts and does anyone > think that I will have problems simply using the rooftops when there is > no > obstructions in between. > > > > > > > > Oliver Leamy > > > > > > > > Ogenek Teoranta, Ballingeary, Macroom County Cork > > > > +353 (26) 47808 ; +353 (86) 8337664 > > > Tim Foster > www.AledoBroadBand.com > Aledo's only high-speed ISP > > The PART-15.ORG smartBridges Discussion List > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe > smartBridges <yournickname> > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe > smartBridges) > Archives: http://198.63.203.6 > > The PART-15.ORG smartBridges Discussion List > To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> > To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) > Archives: http://198.63.203.6 The PART-15.ORG smartBridges Discussion List To Join: mailto:[EMAIL PROTECTED] (in the body type subscribe smartBridges <yournickname> To Remove: mailto:[EMAIL PROTECTED] (in the body type unsubscribe smartBridges) Archives: http://198.63.203.6
