That's an odd way to look at things.
 
Your total output in 360 deg coverage area has nothing to do with dBi.  dBi is merely 
the gain of the antenna.
 
You don't take your radio power, add the gain of all the antennas that point in that 
direction, and somehow spread the total out over all the receivers in that area.  It 
doesn't work that way.
 
You may have 360 deg coverage, but you have 2 separate systems, and you don't get to 
add them together.  In your case, you may have 360 deg coverage with 2 radios and 2 
sectors, but at no point in your coverage area does either system have more than 12dBi 
gain at the base station end.
        -----Original Message----- 
        From: [EMAIL PROTECTED] on behalf of Rudolph Worrell 
        Sent: Sat 11/1/2003 1:02 PM 
        To: [EMAIL PROTECTED] 
        Cc: 
        Subject: RE: [smartBridges] Omni antenna coverage
        
        
        Certainly you do not get to add the gain in one radio.  When you put the 
sectors together your total output in 360 degree coverage area is 24dbi.  This is not 
combined in anyway it is simply what you get when you look at how many dbi's you have 
to cover the area that is intended.
         
        I have 2 190 degree sectors back to back separated by about 5 ft Horizontally 
on a water tower(200ft).  One radio on channel 1 and the other on channel 11.  This 
works great for me and give me a coverage area of up to 15 miles without an amp.  I 
plan to introduce an amp which will most likely increase the coverage by about 5 miles 
or so in open space.
                -----Original Message-----
                From: Jason Baugher [mailto:[EMAIL PROTECTED] Behalf Of Jason Baugher
                Sent: Saturday, November 01, 2003 1:42 PM
                To: [EMAIL PROTECTED]
                Subject: RE: [smartBridges] Omni antenna coverage
                
                
                Possibly, but the assumption is that with 2 sectors, each sector is on 
a separate radio.  Therefore you don't get to add their gains together.
                 
                As far as the mechanical downtilt on the omni, yes, you can do that, 
but why would you want to, unless you are in the unique position of being on the side 
of a mountain with people above and below you on the slope.
                        -----Original Message----- 
                        From: Rudolph Worrell [mailto:[EMAIL PROTECTED] 
                        Sent: Fri 10/31/2003 4:48 PM 
                        To: [EMAIL PROTECTED] 
                        Cc: 
                        Subject: RE: [smartBridges] Omni antenna coverage
                        
                        
                        Yes! 2 190 degree sector gives you 380 overlapping coverage.  
12dbi on one side and 12dbi on the other = 24dBi overall.
                         
                        You can always tilt an antenna to create a down tilt.  With an 
omni you would lose coverage on the side you tilt away from.
                                -----Original Message-----
                                From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] 
Behalf Of Jason Baugher
                                Sent: Friday, October 31, 2003 5:35 PM
                                To: [EMAIL PROTECTED]
                                Subject: RE: [smartBridges] Omni antenna coverage
                                
                                
                                2 180 deg 12dBi sectors combine to make 24dBi in 360 
deg?
                                Mechanical downtilt on an omni?
                                 
                                Maybe my brain is just fried, but something doesn't 
add up here.
                                 
                                 
                                Jason Baugher
                                        -----Original Message-----
                                        From: Rudolph Worrell [mailto:[EMAIL 
PROTECTED] 
                                        Sent: Friday, October 31, 2003 4:26 PM
                                        To: [EMAIL PROTECTED]
                                        Subject: RE: [smartBridges] Omni antenna 
coverage
                                        
                                        
                                        I only use Omni's at repeater sites with low 
number of clients.  I use 190 degree sectors for all serious connections.  12dbi in 
180 or 12dbi in 360.  Well I chose  the 12 dbi in 180 each therefore giving me 24 dbi 
coverage for 360 degrees.
                                         
                                        On your Omnis you should get them with a 3 
degree elec downtilt or use a mechanical downtilt.  Electrical is better!
                                        -----Original Message-----
                                        From: [EMAIL PROTECTED] [mailto:[EMAIL 
PROTECTED] Behalf Of Rob Cleminson
                                        Sent: Friday, October 31, 2003 5:13 PM
                                        To: [EMAIL PROTECTED]
                                        Subject: RE: [smartBridges] Omni antenna 
coverage
                                        
                                        
                                        I too am running with a 12dbi Omni at about 
150â  - customers at about 2-4km get a good signal but the closer you get the worse 
the signal gets â I am about to swap out and try a 9dbi Omni to see if the RF 
pattern improves for the clients that are closer. Failing this I will chuck the 
omniâs and use sectored antennaâs
                                         
                                        Rob 
                                         
                                         
                                        -----Original Message-----
                                        From: [EMAIL PROTECTED] [mailto:[EMAIL 
PROTECTED] On Behalf Of Ian Ellison
                                        Sent: 31 October 2003 14:57
                                        To: [EMAIL PROTECTED]
                                        Subject: Re: [smartBridges] Omni antenna 
coverage
                                         
                                        I am currently running airPointPro Outdoor 
units with Comet GP24-3 Omni's, which is a 12 db antenna.  I am servicing customers as 
far as 5 miles away with sufficient results.  However, the equipment is about 150' 
above ground level which im sure helps.  Good luck.
                                        
                                        Ian
                                        
                                        Derek Breiland wrote:
                                        
                                        
                                        Up to this point I have been running off of 
one tower with 3 sectors.  I am looking at putting an addtional AP up about 6 miles 
from this tower to penetrate into a community of homes that will otherwise be 
difficult to cover due to the number of obstructions not to mention their elevation on 
the map leaves a little to be desired.  It will also enable me to install a less 
expensive CPE at the customer site if I can bring the AP closer to the customer making 
the service a bit of an easier sell.
                                         
                                        I want to utilize an omni antenna in this 
area.  I have not yet decided what to backhaul with yet but I am considering an APPO 
to the new XO2 at the remote.  I can use one radio on the XO2 for the backhaul on one 
channel and the other radio for the access to the customers.  I am not a big fan of 
repeaters unless absolutley necessary.  It seems that most complaints on this site 
have the word "repeater" in the paragraph so I will try and stay away from it.
                                         
                                        My question is to anyone currently working 
with onmi antennes on an AP.  What ranges can I expect for the various dB omni 
antennas?  9dB seems small to me, 12dB is maybe the ticket, 15db - way overkill?  I do 
not want the pattern to get too large to cause problems with my main tower.  I am 
looking at trying to get out no more than 3 miles for the AP.  The AP and omni will be 
mounted on a 40'-50' existing tower.  Also has anyone had better results with one 
manufacturer over the other with the same dB antenna?
                                         
                                        Any suggestions are greatly appreciated.  I 
will be doing more and more of this so I would like to get it right the first time 
based on others experiences in already doing it.

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