I don't hang radio's on towers for lightning reasons. I have installed Andrews 5/8 Heliax and put all my radios at the bottom. This has worked out very well for me and upgrades are a breeze because there is no climbing involved :)
Kurt Fankhauser WAVELINC P.O. Box 126 Bucyrus, OH 44820 419-562-6405 www.wavelinc.com -----Original Message----- From: wireless-boun...@wispa.org [mailto:wireless-boun...@wispa.org] On Behalf Of Scott Carullo Sent: Wednesday, April 29, 2009 10:48 AM To: WISPA General List Subject: Re: [WISPA] RB333/433 eliminating self-interference test Another quick note... if you have individual units why even mount them like this inside a larger box? Why not put individual RB411s in their own small box (say DCE 7x6x2) and put the box outside right under the antenna? Then you would have even more seperation and distribute you eggs a bit more too... Scott Carullo Brevard Wireless 321-205-1100 x102 -------- Original Message -------- > From: "Kurt Fankhauser" <k...@wavelinc.com> > Sent: Wednesday, April 29, 2009 10:36 AM > To: "WISPA General List" <wireless@wispa.org> > Subject: [WISPA] RB333/433 eliminating self-interference test > > About a week ago there was some discussion about 5ghz radio's being > installed in the same board and causing self-interference on adjacent > channels and possible even on the entire band thus decreasing throughput on > backhauls. Because even if you were operating on frequency's 5745 and 5825 > the two radio's would have side lobe harmonics that if installed in the same > enclosure they would still "hear" each other at that short of separation. I > decided to combat this problem and find a solution and share my experience > with the list. > > > > I installed a single XR5 card into 3 different RB433's with indoor > enclosures. I also installed foil tape which I obtained from the local True > Value store for $2.49 on all the vent holes and unused bulkhead connector > holes. This was done in order to prevent RF side lobe leaks from the three > radio's that would escape from the indoor enclosures themselves. Having only > 1 card inside each enclosures I should not have a heat problem as the > outdoor box will not be in direct sunlight. > > > > I then stacked all 3 enclosures on top of each other with dummy loads on > each of the N-bulkhead connectors and did some testing. This is what I > found: > > > > I set the bottom board as AP and the middle board as Client on frequency > 5825. Even with this close of separation the two XR5's could only see each > other at -83 on the same channel. With the top board connecting to the > bottom board they could only see each other at -90. Keep in mind this is on > the same frequency so adjacent channels should be much less than that > possibly even in the -100 ranges. Wish I had a spectrum analyzer. With two > boards separating the AP and Client there was no link at all. The two boards > could not even see each other in an AP scan. > > > > Just as a comparison with the same radio's installed all on a RB600 not on > top of each other but in the adjacent mpci slots the radio's were all seeing > each other at -30's. So I gained roughly -55 db of separation by doing it > this way. So all I would have to do now is make sure that the antennas on > the tower have at least 10 foot of vertical separation and the > self-interference problem should be gone and I should be enjoying much more > throughput! > > > > Thoughts anyone? > > > > > > Kurt Fankhauser > WAVELINC > P.O. Box 126 > Bucyrus, OH 44820 > 419-562-6405 > www.wavelinc.com > > > > > > > > > > ---------------------------------------------------------------------------- ---- > WISPA Wants You! Join today! > http://signup.wispa.org/ > ---------------------------------------------------------------------------- ---- > > WISPA Wireless List: wireless@wispa.org > > Subscribe/Unsubscribe: > http://lists.wispa.org/mailman/listinfo/wireless > > Archives: http://lists.wispa.org/pipermail/wireless/ ---------------------------------------------------------------------------- ---- WISPA Wants You! Join today! http://signup.wispa.org/ ---------------------------------------------------------------------------- ---- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/ -------------------------------------------------------------------------------- WISPA Wants You! Join today! http://signup.wispa.org/ -------------------------------------------------------------------------------- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
