The Atheros chipset differentiating between the Mimo chains does not have to do 
with 45º slant vs 90º…  it means that chain A and B on one radio can be H&V or 
V&H while chain A and B on the other can be H&V or V&H interchangeably with no 
loss because and the chip will just cross them over as needed.  This means that 
hooking up the antenna cables “backwards” won’t effect anything.  It doesn’t 
mean that the orientation of the antenna is irrelevant.

The energy received by an antenna that is out of phase with another antenna is 
much less then if it was in phase that is a principal of radio that no chipset 
will ever overcome.  Now… maybe you can make a magic antenna that is “multi 
phased” such that it can tune in a 45º phase offset signal well.  I suspect 
that the Cambium equipment when properly matched will both have the same 
polorization.

I believe that if your having the same outcome on slant or not slant it would 
be due to one chain being refracted.  For example if your horizontal chain was 
fine but the virtual chain was refracted off something such that the wave was 
on or near a 45º slant then you would have the same basic performance 
regardless of a standard or slant orientation.  This however is a path issue 
not a design characteristic of the chipset or antenna.

FYI, linearly polarization is not a reference to the polarization being on a 
vertical, horizontal or slant axis but a reference to the way the wave 
propagates, circular polarization is an alternative to linear polarization not 
“slant".


Sincerely,
Joshaven Potter
MTCNA, MTCRE, MTCWE, MTCTCE, UACA
Google Hangouts: yourt...@gmail.com
Cell & SMS: 1-517-607-9370
supp...@joshaven.com



> On Dec 4, 2015, at 2:13 PM, Adam Moffett <dmmoff...@gmail.com> wrote:
> 
> The DSP in the ePMP can do some kind of processing to correct for the 45 
> degree offset when you have slant on one end and V+H on the other.  I might 
> not be stating it with the correct technical jargon, but that's the gist of 
> it.  They sell a dual slant sector for the AP with the intent to use it with 
> V+H integrated SM.  
> 
> This is a built in feature of the Atheros chipset, so presumably UBNT radios 
> can do the same thing.  
> 
> That all said...I would try to match them up as just a matter of principle. 
> 
> 
> 
> On 12/4/2015 2:07 PM, Joshaven Mailing Lists wrote:
>> Your AP & SM should always have the same antenna orientation.  I promise you 
>> that you don’t want slant on the AP and not on the CPE.  If the signal is so 
>> obstructed that the orientation is screwed up to the point that unmatched 
>> polarization is actually a benefit then there is something seriously wrong… 
>> 
>> 
>> Sincerely,
>> Joshaven Potter
>> MTCNA, MTCRE, MTCWE, MTCTCE, UACA
>> Google Hangouts: yourt...@gmail.com <mailto:yourt...@gmail.com>
>> Cell & SMS: 1-517-607-9370
>> supp...@joshaven.com <mailto:supp...@joshaven.com>
>> 
>> 
>> 
>>> On Dec 4, 2015, at 1:59 PM, Paul McCall < 
>>> <mailto:pa...@pdmnet.net>pa...@pdmnet.net <mailto:pa...@pdmnet.net>> wrote:
>>> 
>>>  
>>> We are looking at smaller sector sizes for a 5 Ghz ePMP cluster (60 degree 
>>> probably), and am considering my options, which might also increase my gain 
>>> quite a bit.  Using a non-Dual Slant sector such as AM-5AC21-60, would 
>>> increase my options.   There have been a calling threads on Cambium’s sites 
>>> about whether Dual Slant was a big factor at the AP if  the SMs aren’t 
>>> dual-slant.
>>>  
>>> Cambium’s Daniel Sullivan made this comment …  The thread was originally 
>>> about 2.4 Ghz options, so not sure if it applies exactly to 5 Ghz.   
>>>  
>>> Paul
>> 
> 

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