View Full Version : Sectors and a Water Tower
I have been looking for 180 degree HPOL sector antenna's to put on top (the walkway) of a city water tower. Having a hard time finding a 13db.
Then I had a thought, maybe someone has experience with this. What if I put an omni on each side. Would the water tank be wide enough across (thick enough) to block the channel from the other side to get away with this? There would be two walls of steel plus 20 to 30' of water to get the signal to the other side to cause interference. I would probaby have some overlap of signal on the sides.
Thoughts?
lonnie
02-18-2006, 11:09 PM
I don't like 180 degree sectors. The beamwidth graphs look like those of a bad omni. If you look at something like a 120 degree sector it will have a real shape that makes the front and back different, and they still have significant radiation to 180 degrees. They also have higher gains than an omni or 180.
ninedd
02-18-2006, 11:09 PM
I havn't tried this, but I'd have to guess... OH MY GOSH YES. Water & Metal are two of the top attenuators of 2.4 GHz Signals, so I'd guess this is plenty of attenuation between the two antennas.
I should add - I agree with Lonnie. 120 degree sectors will be more common probably, and you have to remember, that 120 isn't a hard wall where there is zero signal. It's only the point of 3db less than center. So, if you get a 17dbi antenna, it's still 14dbi at the 120 degree point, and if you look at the graph, may have lots of signal left where you need it.
Thanks for the input. 120's it is.
simcor23
02-19-2006, 09:43 AM
I am currently on a water tower and I have 4 VPOL 17dbi 90's and it works great, but I am using 5.8ghz and WARS only even on the cpe. But we can get great signal 20km's out without blinking an eye.
Skaught
02-19-2006, 11:55 AM
do not use onmi's. I tried ti once as a test and got the strangest coverage patterns as the metal silo it was on the side of caused all sorts of whacky reflections.
metal is not an attenuator of RF, it is a reflector.
Any suggestions on which HPOL 120 antenna's to use?
Something with a higher gain (at least 13db), more the better to cover the db loss on the edges.