I agree... we are saying the same things... just in different ways :-) Many vendors now are utilizing integrated OMT's... the Ceragon IP-20S uses it for instance.
Long story short - don't worry if the BOM says Single Pol if it includes an OMT. Thank you, Daniel White afmu...@gmail.com Cell: +1 (303) 746-3590 Skype: danieldwhite Social: LinkedIn: Twitter > -----Original Message----- > From: Af [mailto:af-boun...@afmug.com] On Behalf Of ch...@wbmfg.com > Sent: Friday, October 30, 2015 10:41 AM > To: af@afmug.com > Subject: Re: [AFMUG] Dish polarity question > > I think Daniel and I are saying the same things. > > -----Original Message----- > From: Daniel White > Sent: Friday, October 30, 2015 10:13 AM > To: af@afmug.com > Subject: Re: [AFMUG] Dish polarity question > > This comes up all the time with many manufacturers. > > Almost all licensed microwave antennas a WISP is going to come in contact > with have circular feedhorns, meaning their polarity is determined by the > interface on the feedhorn. Typically, they are rectangular and single polarity. > > Then an OMT is added... depending on the radio it may be an external or > internal device. This combines the transmitters into a circular feed. > > No voodoo required. The OMT makes a single polarity dish dual polarity. > > Thank you, > > Daniel White > afmu...@gmail.com > Cell: +1 (303) 746-3590 > Skype: danieldwhite > Social: LinkedIn: Twitter > > > -----Original Message----- > > From: Af [mailto:af-boun...@afmug.com] On Behalf Of Craig Baird > > Sent: Friday, October 30, 2015 10:07 AM > > To: af@afmug.com > > Subject: [AFMUG] Dish polarity question > > > > We are getting ready to put up a licensed 11 GHz 2+0 link using > > Cambium PTP820S radios. We have two 11 GHz frequencies that are > > oppositely polarized for use on this path. I had assumed that we > > would need to use dual polarity dishes in order to make this work, but > > Cambium and our > vendor > > are saying that we need to use single-pol dishes. This completely > > baffles > me. > > How can a single-pol antenna transmit in two polarities? Cambium's > > answer is that it's because we're using an OMT, and that device > > essentially makes > the > > single-pol antenna circularly polarized, so it will transmit both > polarities. My > > first thought is "what kind of voodoo is this?" Will this really work??? > I'd sure > > hate to start transmitting, only to find out from an existing license > holder that > > we're interfering with them because one of our frequencies is coming > > out the antenna in the wrong polarity. > > Can someone confirm for me that this will really fly? > > > > Thanks! > > > > Craig > > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus
