You lose ~3db from the cross to linear polarization difference. But I assume you win ~3db from the incoming signal now being received and summed by 2 antennas.
>From my understanding, say you have 30db signal. Instead of getting signal A on port A at 30db and signal B on port B at 30db, you get: -signal A on port X at 27db and port Y at 27db, the latter out of phase 90deg due to polarization -signal B on port Y at 27db and port X at 27db, the latter out of phase 90deg due to polarization The chipset used in ePMP sums up both (out-of-phase) signals for A and gets a 30db signal, same for signal B. Whether the chipset in other wifi products does the same is unsure, but I assume most modern Atheros chips do it. On Thu, Aug 11, 2016 at 12:17 PM, Chuck McCown <[email protected]> wrote: > Yes they did say that, and I read the white paper, and I think I > understood it at the time. I think they used some kind of special sauce to > make that true though. I don’t think it would apply to any two radios. > > *From:* TJ Trout <[email protected]> > *Sent:* Thursday, August 11, 2016 1:09 PM > *To:* [email protected] > *Subject:* Re: [AFMUG] Using AirFiber 5x dishes with non-Airfiber radios > > Didn't cambium say that you can receive slant using a hpol/vpol cpe and > not loose any performance? Or is that with cambium CPE's only? > > On Thu, Aug 11, 2016 at 12:05 PM, Chuck McCown <[email protected]> wrote: > >> You lose, but not quite that bad: >> >> 20*Log (Cos(angle)) = 3.01 dB >> >> >> *From:* Josh Luthman <[email protected]> >> *Sent:* Thursday, August 11, 2016 12:59 PM >> *To:* [email protected] >> *Subject:* Re: [AFMUG] Using AirFiber 5x dishes with non-Airfiber radios >> >> BOTH sides should be slant. That's it. >> >> One slant and one VH you'll lose I think 15db? >> >> >> Josh Luthman >> Office: 937-552-2340 >> Direct: 937-552-2343 >> 1100 Wayne St >> Suite 1337 >> Troy, OH 45373 >> >> On Thu, Aug 11, 2016 at 2:57 PM, Paul McCall <[email protected]> wrote: >> >>> Probably a dump question, but is there any downside with using a >>> AF‑5G30‑S45 to use with Mikrotik radios? I wouldn’t expect the X polarity >>> to hurt performance, but don’t want to assume. >>> >>> >>> >>> We have some links to put up that long term may become AirFiber 5X >>> links, thus the thought. >>> >>> >>> >>> >>> >>> >>> >>> Paul McCall, President >>> >>> PDMNet, Inc. / Florida Broadband, Inc. >>> >>> 658 Old Dixie Highway >>> >>> Vero Beach, FL 32962 >>> >>> 772-564-6800 >>> >>> [email protected] >>> >>> www.pdmnet.com >>> >>> www.floridabroadband.com >>> >>> >>> >>> >>> >> >> > >
