Indeed and this seems to be what is happening with my RadioWave antennas. I
did ask about this prior to purchasing the antennas and was assured by the
vendor that there was isolation between the ports. Testing suggests
otherwise. Has anyone else used dual-polarized RadioWaves in this way? If
the antennas do have bonded circuitry for the different polarities and I use
both polarities for the same signal what am I likely to see improved?

-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Tom DeReggi
Sent: 17 January 2006 15:19
To: WISPA General List
Subject: Re: [WISPA] Multiple Radios on Single antenna

On a side note, for general info, not necessarilly applicable to the task in

question....

Just because an antenna is Dual polarity, does not mean that both polarities

can be used at the same time by seperate signals. The wiring/circuitry (what

ever its called for an antenna) may be shared by the two pols, and bonded 
togeather in some way.  The DUAL Polarity antenna has to be designed with 
two completely unique circuits to the antenna from the N connector, for both

pols to be used at the same time.

Secondly, Any two antenna elements near each other can work togeather two 
create the antenna beam. Just like an Omni or Panel antenna that is really 
just several antenna elements place appropriately to work togeather to 
increase gain and reduce beamwidth.

Its very common to use both polarities at the same time for the same signal,

but a much different matter two have two seperate signals and not have them 
interfere.

Polarity isolation is often not enough when smack dab right next to each 
other. In theory 90 degrees off polarity equals 100% isolation, but in the 
real world its closer to 15-20 DB, but is that considering between the 
antennas elements right there, or signal comming from the enviroment getting

shielded out? Who knows.

Its very possible that 5.2 and 5.8 may not be far enough apart from each 
other to colocate on the same antenna, however I don't know that for a fact 
(harmonics and stuff like that).  However, I am aware of many successfuly 
using 2.4 and 5.8 from the same antenna.

The point I'm making is not what can and cant be done, just that not all 
antennas Dual Pol antennas are designed the same, and what you can pull off 
on one, may not be able to be pulled off on another type.

Tom DeReggi
RapidDSL & Wireless, Inc
IntAirNet- Fixed Wireless Broadband


----- Original Message ----- 
From: "Paul Hendry" <[EMAIL PROTECTED]>
To: "'WISPA General List'" <wireless@wispa.org>
Sent: Monday, January 16, 2006 2:23 PM
Subject: RE: [WISPA] Multiple Radios on Single antenna


> Bob, are you saying that you are running 2 simultaneous links through 2
> separate StarOS powered WRAP/CM9 on a single dual-polarized antenna with 
> no
> other hardware? I have tried this on 2 separate links running horizontal 
> at
> 5.8 and vertical at 5.2 but still cannot download through one link without
> impacting the other. What am I doing wrong? The radios are connected to 
> the
> antennas via very short pigtails and about 2 feet of LMR-400.
>
> -----Original Message-----
> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
> Behalf Of Bob Moldashel
> Sent: 16 January 2006 15:18
> To: WISPA General List
> Subject: Re: [WISPA] Multiple Radios on Single antenna
>
> Why would you use an isolator????   If we are talking possible adjacent
> channel interference then an isolator is not the cure, aditional
> filtering would be.  But most equipment should be able to work in this
> environment without it. I have sites that have 4 WRAP boards with CM9's
> sitting right next to each other on the next adjacent channel with no
> issues.
>
> In addition, the loss of power is not acceptable (though it wouldn't be
> half power at 5GHz.).
>
> -B-
>
>
>
> Richard Goodin wrote:
>
>> Go to some of the hard core LMR delers and ask for isolators, (They
>> will cut your power in half).  Your LMR dealer will need to know
>> power, frequency, type of connectors.  This may work, I do not know.
>>
>>     ----- Original Message -----
>>     *From:* Paul Hendry <mailto:[EMAIL PROTECTED]>
>>     *To:* 'WISPA General List' <mailto:wireless@wispa.org>
>>     *Sent:* Monday, January 16, 2006 5:14 AM
>>     *Subject:* RE: [WISPA] Multiple Radios on Single antenna
>>
>>     Radios are WRAP/CM9's with StarOS on RadioWaves SPD2-5.2NS. Is there
>>     anything special you do/use to get this to work? Only things I can
>>     see that
>>     would help are band pass filters.
>>
>>     -----Original Message-----
>>     From: [EMAIL PROTECTED]
>>     <mailto:[EMAIL PROTECTED]>
>>     [mailto:[EMAIL PROTECTED] On
>>     Behalf Of Bob Moldashel
>>     Sent: 15 January 2006 23:53
>>     To: WISPA General List
>>     Subject: Re: [WISPA] Multiple Radios on Single antenna
>>
>>     I should revise that to say we do it on dual polarity antennas.
>>     Not 2
>>     radios on one antenna....
>>
>>     -B-
>>
>
> -- 
> Bob Moldashel
> Lakeland Communications, Inc.
> Broadband Deployment Group
> 1350 Lincoln Avenue
> Holbrook, New York 11741 USA
> 800-479-9195 Toll Free US & Canada
> 631-585-5558 Fax
> 516-551-1131 Cell
>
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