Just checked the specs for the RadioWaves antennas that I'm having the problems with and see that they have 28dB "X-Pol. Rejection" would this suggest that the circuitry controlling the 2 feeds are separate? If so, is there anything else that could be preventing us having 2 separate simultaneous links running through these parabolics?
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Bob Moldashel Sent: 17 January 2006 18:51 To: WISPA General List Subject: Re: [WISPA] Multiple Radios on Single antenna Sorry but this whole thread is going sour fast..... 1. Dual Polarity antennas work for transmit and receive. They are not TX only or RX only in configuration. 2. The normal isolation between vertical polarity and horizontal polarity can range from 10-30 dB depending on the operating frequency. 3. The biggest issues to using 2 radios on the same dual polarity antenna is the adjacent channel rejection, x-pole polarity, TX power levels and Receiver sensitivity.. 4. 802.XX radios will not work on the same channel because while one radio is transmitting on 5825 GHz. the radio on the other polarity is receiving on the same channel. Considering there is only 10-30 dB of seperation, the radio RX levels will only be reduced by that amount causing receive interference. 5. We have more than 20 dual polarity links running FD radios such as Proxim Tsunamis operating in the same band. Granted, they have much better filtering than the basic 802.XX radio but they work flawlessly.. 6. We presently have 2 DP links in place with 802 style radios. One of the links consists of WRAP/CM9's operating in 5.7-5.8 Ghz. The other has a Proxim MP.11a on one plane and Tranzeo TR-5a on the other. One link is 6.5 miles, the other is 7 miles. There is no desense between radios and both operate fine without interference issues. 7. While Tom may be experiencing the tower rental issues regarding antennas, we have not seen this in the NE. Most leases we have negotiated are based around wind loading on the tower. Like everything, dual polarity antennas have a place like all other equipment. The link just needs to be engineered to operate properly. -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 -- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.14.19/231 - Release Date: 16/01/2006 -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.375 / Virus Database: 267.14.19/231 - Release Date: 16/01/2006 -- WISPA Wireless List: [email protected] Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
