-
65cm dish is not small and will need a reasonable mount if it is withstand any wind event. The 32mm galv pipe would be my choice. Think also how much time/km's you'll spend on alignment....do it once and right.
-
I wasn't really thinking of guying for support against failure - but that is something to consider. I was thinking more along the lines of rigidity - preventing the tip of the mast from bending over under wind load.
With the wind blowing directly from behind the dish, the dish will point down a bit. A 1cm deviation at the end of a 2m section of mast, will change the beam centreline by at least 275m at the distance involved.
What range of geometry is available from the dishes? -
Have you ever heard of a tensegrity mast?
-
Are you sure the gain is that high?
-
Think also how much time/km's you'll spend on alignment....do it once and right.
Very good advice!Are you sure the gain is that high?
The antenna I'm looking at is the AF-5G30-S45 65cm, 30 dBi dish, but if I can get away with the AF-5G23-S45 (37cm, 23 dBi) then I'll use that.
The ones I have for testing are around the 37cm mark I think. -
Did the manufacturer give you a figure for the beam width - how critical the alignment is?
You should consider using a mesh dish to reduce wind loading.
Any sold flat or concave antenna is going to have to be mounted extremely well or it will move with the wind.
There are very high gain panel antennas too. Typically PCB elements and a reflector. 17db is quite achievable at 2400 MHz in a compact design.
At 5 GHz the loss in the PCB material might be too high.
You should consult your area's historical weather data to find out what kind of winds are seen there during storms. -
Did the manufacturer give you a figure for the beam width - how critical the alignment is?
You should consider using a mesh dish to reduce wind loading.
Any sold flat or concave antenna is going to have to be mounted extremely well or it will move with the wind.
There are very high gain panel antennas too. Typically PCB elements and a reflector. 17db is quite achievable at 2400 MHz in a compact design.
At 5 GHz the loss in the PCB material might be too high.
You should consult your area's historical weather data to find out what kind of winds are seen there during storms.
I'll be using 5 GHz so a mesh dish isn't really that suitable (or available from UBNT). I need the higher gain to work over such a long distance. Remember, these radios don't output a signal any stronger than good quality Wi-Fi gear and the EIRP must remain within the ACMA limits.
Alignment will be fairly narrow being 5 GHz. There are 3 options for antenna that I'm looking at:
AF-5G23-S45 - 37.8cm, 23 dBi dish (10° beamwidth)
AF-5G30-S45 - 65cm, 30 dBi dish (5.8° beamwidth)
AF-5634-S45 - 105cm, 34 dBi dish (3° beamwidth)
If I can get away with using the smaller dishes, that's great, but I have trees to contend with so it will depend on how much of the 1st Fresnel zone is obstructed.
All three antennas have a 45° slant which should assist with noise rejection.
Ubiquiti also make a "Precision Alignment Kit" for fine tuning alignment over long distances. Don't forget though, I'm "only" needing 55 KM range, the Airfibre radio that I'm considering will do 200+ KM with the right antenna and conditions. -
Watching because this might help me get 55 meters
-
This is a good resource to get the wind velocity in realtime .
https://www.windy.com/?-34.253,142.559,6
-
Here are the new record holders and their antenna.
-
Hi all, apologies for the lack of posts/updates over the last few weeks. Work has been crazy busy so I haven't had a lot of time to test.
I did visit and visually check out the 'Station B' end and it looks like we might have issues getting over the top of a few rooftops.
However not all is lost, I have alternative plans to set up a link to another site (47 kilometers away) which is looking much more promising. I'll still conduct some tests in the coming weeks to the original site but I don't like the chances of it working.
Since I'm on Australia's new National Broadband Network (NBN) for my internet connection (with no real alternatives) and considering they refuse to replace any of the faulty and ageing copper in the street (which is causing me drop-outs and less than expected line sync speeds), I'm looking at moving my service to the alternate address (which is much closer to an NBN/VDSL2 node than I am) and access the internet over the Ubiquiti link. It should (in theory) be much, much faster and more reliable than what I'm experiencing now.
Updates will be forthcoming soon! I promise!