This may not strictly be a question about mikrotik, but maybe someone can give ma a quick answer.
I currently have a highsite with an 12dBi Omni antenna, servicing about 5 clients. We are having lots of problems with ESD damage during thunder storms. I am considering using a sector antenna instead. We are using a RB433 with one wireless interface for client distribution and the other 2 for backhaul links. If we add more than one sector it will be necessary to change to a routerboard with more wireless interfaces, so I want to get away using only one sector if possible.
The two furthest clients are unfortunately about 90 degrees apart, and with the 12dBi Omni get just acceptable signal strengths, I wouldn’t want to have much of a drop in their signal levels.
Now if I use a 120 degree 15dBi antenna for example the antenna pattern shows 0dB at 0 degrees and about -3.33dB at 45 degrees. But since it is a 15dBi antenna I assume the gain would be 15dBi at 0 degrees, how do I calculate the gain at 45 degrees? Can I simply say it will be 15 - 3.33 = 11.67dBi at 45 degrees? In that case it might be worth a try.
Thanks