I have a (AP) rb411ar XR9 15db grid antenna and (Station) rb411 XR9 9db yogi. What settings can i or should i used for a NLOS, from Site A to Site B is about 4 to 6 Km.

that a very wide question
do you have them linked up and what kind of signal are you getting?
make sure that your antennas are high enough, at least 14m minimum
site A is about 6m, i need to go 8 more.
Can you use http://www.ligowave.com/linkcalc, its free just register (or similiar) and post the terrain profile, satellite photo does not reveal a lot and we cannot tell how much of a nlos issue exists between the different points?
OK, tHANKS I WILL CHECK IT OUT.
This doesnt look too good.!
your going to need to put a repeater on the high point.
I agree and NLOS is out of the question with that terrain?
I posted the wrong picture above the correct one is worst than that one.
If I got to use a repeater for 900mhz so what would be the difference if i use a 2.4ghz radios?
where is the correct picture?
Here it is.

From terrain profile you would need at least 3 repeater sites?
Another approach is rather than direct link with repeaters from A to B, i would check the possibilty of picking a location either side of the direct line which is from your graph is 3.2miles and see if just one repeater will do?
ok im looking into it to used just 1 repeater.
thanks
I thought that 900mzh could go through almost any thing?
900 MHz has a better ability to penetrate obstructions than 2.4 GHz, such as a few trees or walls, but NOTHING can penetrate the ground like that path needs. Even through trees there is significant signal loss.
If you can find 900mhz equipment that will go through that terrain, please let us know as we will be first in line to purchase?
Thanks to all for the help. ![]()