How about just decreasing the xr5 power level to about 200mw I wouldn't put a cm9 on a tower or so
Scott Carullo Brevard Wireless (321) 205-1100 x102 On Apr 29, 2009, at 4:31 PM, Tom DeReggi <wirelessn...@rapiddsl.net> wrote: > The first question is "why are the 4 mpci cards in teh RB600 seeing > each > other so loudly"? > There lies the problem needing fixed, because of course we want to > use one > RB433, instead of 3 RB433s, to accommodate 3 mpci cards. > (even if different channels and freqs). > > First question to you... "am I assuming correct that you still kept > the > dummy loads on each of the mPCI cards, when testing all in teh same > RB600"? > > What is a bot disturbing is that you said you used a XR5. That means > the > card had a single antenna connector and a MMCX style, which is > supposed to > give better isolation. > > (note: some have advocated that Ufl is as good as mmcx, regarding > rssi loss, > stating that the UFl connector itself has less loss than the gain > MMCX adds > by enabling thicker pigtail cable. I always still prefer MMCX > because it is > more rugged abd less likely to break pigtails connectors in things > like > Rootenas that are not easy to access with short pigtails. But surely I > thought mmcx would also add better shielding/isolation from outside > sources.) > > So using XR5s, it would infer that the cards saw each other because > either > loss from pigtail cable, loss from mmcx connector, or simply the cards > electronics. > The next relevent info might be to determine if it is the amp > circuitry > driving this interference. Just like a pair of PC speakers can > sometimes > pickup music radio. > > For years Lonnie (StarOS) gave teswtimonials for lower power CM9s > performing > better than Amplified cards (SR5) for short range applications, > because they > were quieter. > > So there is about 8db difference between a SR5 and a CM9. I wonder > if you > repeated your tests, but used CM9's instead (no ext embedded amps), > whether > you'd just hear the other adjacenet radios at 8db lower, > proportional to the > spec of the radios, or if you hear the otehr radio much much less, > because > it doesn;t have the amp to pcikup the interference? > > > Tom DeReggi > RapidDSL & Wireless, Inc > IntAirNet- Fixed Wireless Broadband > > > ----- Original Message ----- > From: "Kurt Fankhauser" <k...@wavelinc.com> > To: "'WISPA General List'" <wireless@wispa.org> > Sent: Wednesday, April 29, 2009 10:33 AM > 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! 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