If it is a circular waveguide flange. If the antenna has a rectangular
waveguide flange the OMT will not work with it.
-----Original Message-----
From: Daniel White
Sent: Friday, October 30, 2015 11:29 AM
To: af@afmug.com
Subject: Re: [AFMUG] Dish polarity question
If the antenna vendor and OMT vendor are the same, may not be an issue.
Worst case if there is a waveguide flange, you can buy a waveguide OMT and
do waveguide + remote mounts for the radios.
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 11:24 AM
To: af@afmug.com
Subject: Re: [AFMUG] Dish polarity question
Interesting... this is exactly what I'm wondering... see my last post...
Craig
Quoting Gino Villarini <ginovi...@gmail.com>:
> But he should worry if he plans to reuse existing antennas. If the
> antenna coupling is rectangular, theses no way to inject both polarities
> into
it.
>
> On Fri, Oct 30, 2015 at 1:04 PM, Daniel White <afmu...@gmail.com>
wrote:
>
>> 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
>> >
>> >
>> >
>> > ---
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>>
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