27Dbi or 31Dbi

[KillerB]

Hi there witch are better to use on an backbone 5ghz 27dbi or 31dbi some inputs plz...

 

[n1ghtwalk3r]

31 ofcruse it goes further deeper through trees and much more powerfull

 

[portcullis]

Depends on what you are doing and what the distance is.

Have you calculated a link budget?

 

[warwickw]

I've got 2x 27dbi's back to back on about a 12 km link with CM9 cards working perfectly, I've had 2x 31dbi's back to back on a 50km link with CM9 cards also working very well.

The important factor is absolutely clean line of site, clear fresnal zones, and very good installs.

I'd suggest staying away from the 31dbi's as much as possible, they catch the wind really well.

 

[KillerB]

i think the link will be about 8km clear line of site and want to use R52H cards.

 

[rebel998]

27 Should be good enough.

 

[portcullis]

Actually, 24dBi is already too much over that distance.

 

[Elvis007]

Use 27dbi grids, will be perfect. The R52H cards will not help at that shot distance, rather use the R5H or if that's to expensive just get the R52.

 

[KillerB]

Use 27dbi grids, will be perfect. The R52H cards will not help at that shot distance, rather use the R5H or if that's to expensive just get the R52.

There are an huge difference in performance when the data starts running when using the R52H and the normal R52

 

[DenSweep]

31 ofcruse it goes further deeper through trees and much more powerfull

Problem with 31's though, is that your alignment must be spot on with extremely little to no deviance.

And like someone else said, they are wind magnets. Despite those little ribs, it is still very wind resistant.

I would go with 27db. Have a look at the WUG communities, almost all their backhaul links run 27's. I'm abt to link from Pta into Jhb, just over 50km with 2 27's.

 

[KillerB]

Thx for the input....

 

[j@w]

Rather get FO-5 Radios than R5H, FO-5 are WAY better and cheaper

 

[Fr0sT]

Are the R5H not stronger?

 

[portcullis]

The F.50Pro is a monster of a radio. I'd chose it over the R5H every time.

 

[Pyro]

From a purely signal POV, the 31db should be better for linking two points. Since it's more "focussed", it should get as much noise from other sources, and won't be throwing radiation over areas that don't need it.

 

[Atti2de]

Fair enough pyro,

But a short distance like this you could easilly use 2 x 24dBi grids and the FO-5's (turning the power down a bit as well).

31dBi grids would simply be an overkill and I would NOT recommend it.

 

[Fr0sT]

I have 2 x 31dBi antennas that i want to put on a 11km link next week. What will u recommend, for a stable link?

 

[portcullis]

2 of these.

 

[Tarzan]

The F.50Pro is a monster of a radio. I'd chose it over the R5H every time.

Where do you buy them in Cape Town / online?

Thanks

 

[portcullis]

Where do you buy them in Cape Town / online?

Thanks

Uniterm or Miro.