Your not going to see much difference with stand offs with sectors you will notice a big difference if your using Omni antenna's
If you where using ubiquiti AP's you would need 10ft separation Epmp are a little higher end on the RF shielding so you can get away with a little less — Sent from Mailbox On Thu, Sep 25, 2014 at 8:51 PM, Paul McCall via Af <[email protected]> wrote: > Over the years we have employed different philosophies on mounting sectors to > towers. Our reference point was the Moto 100 series connectorized radios > with sectors. We started out with 18" standoffs on a Rohn 25G tower, because > some "smart guy" suggested that was what we needed. Another smart guy > suggested 24", so some of them were done like that. Then, someone else > suggested that we really didn't need standoffs at all, that they could be > mounted each on a leg of the tower and we would be fine. (we always ran 3 > 120 sector/AP configuration per tower in 2.4 Ghz). As far as difference that > we could measure, we found no difference in AP to SM performance when we > measured at any distance of connection. Maybe we were missing something, but > anyway, we settled on mounting them directly on the tower leg. > Moving forward to today. We have been installing the ePMP 2.4 series instead > of 100 series 2.4s. The installation techs mounted them back to back, with > North/South on one frequency (Front/Back Frequency Reuse configuration) and > East/West on the other frequency. One of the 4 sectors had to have a custom > mounting bar made to replace the short stubby one that comes with the sector, > thus allowing the 2 sectors (North and East at 90 degree offset) to be put on > one leg right near each other. Again, this is Frequency Re-use a bit of a > different scenario. > Anyway, today in working with Cambium, they told us we need to have at least > 3 ft of vertical separation between each radio on the same frequency, so > North and East could be at one level (dif. Frequencies) and South and West > would be vertically separated. Alrighty then :) ..... so we have 6 towers > to go move things around on. We are going to some test tomorrow on the first > tower to see exactly how much separation yields us how much F/B isolation. > Using ePMP eDetect feature, that should be pretty easy to see. > OK....so here is where I want opinions. Really I'd like "expert advice", but > I will settle for opinions :) > How far "should" these sectors be "stood off" from the tower, if at all? I > am not expecting to be able to measure any difference with the F/B ratio > data, so its back to this is "all theory". Is the standoff question a > front to back issue at all, or a "we want the metal" sector away from the > metal tower a little bit? > Paul > Paul McCall, Pres. > PDMNet / Florida Broadband > 658 Old Dixie Highway > Vero Beach, FL 32962 > 772-564-6800 office > 772-473-0352 cell > www.pdmnet.com<http://www.pdmnet.com/> > [email protected]<mailto:[email protected]>
