VHLP and RW antennas that are sold with the 820S work with an OMT -----Original Message----- From: Af [mailto:af-boun...@afmug.com] On Behalf Of ch...@wbmfg.com Sent: Friday, October 30, 2015 12:41 PM 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
