MikroTik

I have wireless connection to a building. On top of the building i am running a mikrotik system. The antennas are 16dbi slotted wace guide, horizontaly polarized. I have a wireless router with a 12dbi horisontaly polarizes yagi. Now why does my signal drop from 90% coms tio 40-50% coms. There is no water in the connectors, we checked. Does this poor performance in the weather have anything to do with the fact that we are using Horizontaly polarized antenna.

Noir,
I have a large Mikrotik network in South Africa, if you want you can contact me for local support. visit http://www.dbg.co.za

Is the slotted waveguide open or sealed up, we've had problems with some that filled with water!

They have some sort of plastic material covering the slots.

Well, we had the same problem with the sloted wave guide on a bad weather. You should drill at least two holes at bottom of the antennas so if anything enters inside it would go out It's working for us,.Cheers...

FYI ... we use pole Omni, flat panels and some grids and have had no weather effects ... we get everything from freezing temps -36deg , freezing rain... and very humid summer weather (why do I live here)

Having been graphing signal strength for awhile now, we see small daily variations do to, I expect, the sun. We also see small variations do to fog. The one freezing rain storm we had last winter though, over the course of an hour, we could see AP's getting covered in ice and every customer slowly dropping in strength until they fell off, while other AP's stayed up and you could see individual customers ice up.

It's not common, but weather does effect these things.

Uni what type of antennas were u using flat panels? ... I really watch the weather up here and worry about what antennas will stand up the best to winter weather...

Our AP's are a mixture of stick omnis, grids, dishes and sectors, it was the grids and dishes that appeared to be effected by the ice because of the exposed feedhorn. The customers are pretty much all flat panels with that nice flat surface for the ice to build up on if it was facing the right direction I guess.

well we use FPs from several manufacturers and have had no icing problems ... maybe just luck?

Maybe luck, maybe design of the panel. I've noticed that the new radios we get from Tranzeo have smooth surfaces, the older ones have a mottled surface that may have iced up easier in freezing rain.