Hi…I am using RB433 router board with 15 dbi omni in a campus. what configration i have to do to make this omni hlep me increasing the range …i am not using this omni for point to point connection.i am using only it to broadcast the signal, so that maximum users can use internet.
band=?
frequency=?
channel width=?
protocol=?
antenna mode =?
antenna gain=?
Also suggest me if there are any more configration i have to made this omni to increase the range of wireless card (CM9-GP)
Use sector antennas instead the omnidirectional.
I have Omni antenna 2.4 GHz, does it works
Your antenna is strong enough but your card is the weak point. You can only use up to 18 dBm @ 802.11g 6mbps data rate with -90 on Rx sensitivity . I would find a card that can use more output power, plus this seems like an old card and better to upgrade to an a/b/g/n 2.4Ghz with like 20-25 dBm output. see here: http://www.wisp.net.au/wlan-80211abg-minipci-module-p-86.html
The other issue is that even if you boost the output power, the wireless clients still have to be powerful enough to transmit back to the station, not only “see”.
omnitik 5 AC is 7.5 dBi antenna but output power of 31dBm @ a/n/ac 6mbps datarate to -96 on Rx sensitivity..work easily at 1500M…with sxt lite 5 ac (for example)
He is using 2.4Ghz not 5Ghz.
A BaseBox 2 with dual pol omni would work much better.
I know that..just an example… 
there are stonger mini-pci cards. for example: https://www.gandalf.nl/pdf/SR2.pdf (mikrotik compatible? not sure, but there are better cards)
And yes, of course a fully upgrade would be better but he didn’t ask about that so please don’t “talk down” to other people trying to help. and where I live, 5Ghz is just as saturated as 2.4Ghz in remote areas with a lot of WISP providers.
yes i am using 2.4 ghz omni antenna…
actually i am facing problem from last few months.
i actually forgot my password so i reset my router board and configure it again, but i am not getting the range which i used to get few months before,i need to sit near router board to get the signal on my laptops and when i move few meters from my router board the signal gets very poor (only a single bar). i think i am not doing the proper configration.
That is very poor output. Have you checked the pigtails are connected properly. Even consider changing them out. You will need to reset your router to factory if you cannot remember the password. Rb433 boards have a reset jumper that you short out during a reboot.
Sent from my ONEPLUS A3003 using Tapatalk
The radio card may have two outputs aux and main. It’s possible you set up the wireless on the wrong radio output
Sent from my ONEPLUS A3003 using Tapatalk
Also consider that as the gain of an Omni aerial increases the vertical coverage decreases i.e coverage below the horizontal plane of the aerial.
So if you have a 3 dB Omni you get not so much distance but coverage is good below the aerial. As this gain increases the distance improves but coverage below the aerial decreases so you need to make sure your aerial is not too high or all signal will be above your customers 
I’ve never seen a 15dbi antenna that worked better than 8dbi.
Best antenna in 15 dBi, D-Link ANT24-1500
it is excellent.
A friend replied you something very important, and I repeat
A wireless communication is the same that TWO people talking
Is we are separated for 200 meters, and in one side I have a loudspeaker, you in the other side, maybe you can listen me, but if you talk normally… (a phone, tablet, without hight power+antenna) I (AP) won’t be able to listen you (your answer)
In a wireless network, both side must be balanced for a correct development!!!
Thank you all… problem solved…
The radio card may have two outputs aux and main. It’s possible you set up the wireless on the wrong radio output
on which radio output i have to set wireless
on which radio output i have to set wireless