There are a lot of people saying that their radios are being killed by the omni’s that they have.
Some say that grounding fixes the problem and some say it does not.
So please list your omni’s that work fine.
THE OMNI LIST:
I saw some mention in other threads about this. I guess I don’t understand the scientific reason this could happen. How does radiating 360 degrees kill it anymore than say 120 degrees. Now I am aware that a omni will pick up more noise (simply because its in every direction). Maybe that has something to do with it.
Eric
Take a non-DC grounded omni. No amp. Put it on the tower or building top. Let the wind blow. Not enough power to run the rack, but enough to jump the little capacitor on the WLAN card.
Same goes for adjacent commercial transmitters even if they are DC grounded but resonant.
Just two cents from WISP and HAM fun and expense…
Sometimes more expenses than fun.
Mike
As far as preventing this from happenning, what would be recommended as a good ground? Normally, I ground the antenna and put a lightning arrester on the coax. If the tower has a good ground then I’ll ground to it. Otherwise I’ll run to about 3 ground rods to the base. In this scenario, could ambient static electricity (non-lightning) in the air still fry the atheros cards?
Eric
As I said in another post my friend that had the problem solved it by grounding the poll that every thing is connected to. Some people say that they have all their equipment grounded but still loss the cards.
He is using PacWireless 9 and 12dbi omni’s and after grounding has not lost any cards.
it has nothing to do with omnis, i have used all configs out on the market.
CHECK http://forum.mikrotik.com/viewtopic.php?t=8719 and READ CAREFULLY.
IMPACT IS COMING ON MPCI, even when using on free channel, impact is coming so your own mpci card starts transmitting the other signal from others so the RF switch goes dead.
CHECK > http://forum.mikrotik.com/viewtopic.php?t=8719 > and READ CAREFULLY.
Not sure if this thread tells me alot. I did see about 30 posts from yourself in it.
-Eric
I’ve never heard of an antenna “killing” a radio…
I’ve never had a radio stop working. But I guess that’s just good luck.
I only posted this because some people are saying that their radios stop working that connected to the omnis but not the grids or sectors that are at the same site.
I just say ground it better, but then they say they are grounded good.
I hat this problem a year ago at one location (Pac Wireless 12 dBi). As I could not find the reason, I replaced the AP-Hardware complete (no aeheros anymore).
Now I have same problem with a Pac Wireless 12 dBi at a new location.
Everything ist grounded very well. Within the last 5 days I lost 3 CM9s on heavy weathers.
This evening, I will replace tihs omni by two new sector-antennas and observe the situation.
I have many other locations with another omni (http://www.wimo.de/bilder/18590_6_klein.jpg). I have no problems with them. Perhaps its the design of the Pac-Wireless omni antenna. My other omni has a metal-head on the top. Pac-Wireless not ?! Is this the reason ???
Is there anyone else with dying cm9s in combination with another omni than pac-wireless?
Yes, I forgot the brand but I have lost cm9’s with omni’s
I think its not weather but noise that makes omni no good for cm9
I lost each of my cm9 only during stormy or rainy weather.
Well, I see GotNet is quite right. The problem is with atmospheric electricity. Omnis, sectorial antennas and directional ones have different structure, one type is closed-circuit while others are open-circuit. There is electricity in the air so non-DC grounded or improperly DC grounded omni antenna works as a capacitor. After while, this capacitor discharges - into your card, of course. Usually, this result in that fact: after year or more your CPEs show weaker signal from BS. The killing occurs not so frequently, but equipment starts working worse as before, however.
Find a ham-radio amateurs in your city and ask them to check your antennas, I guess they will help.
Grounding is a science I don’t understand too well. So is a DC-Ground antenna any different from a regular grounded antenna? I think alot of us here use Pac Wireless 12db omni’s. What would you need to accomplish this? (Forgive me, if this is a stupid question) But I lost a CM9 card in this same manner during a rainstorm, and was hoping to prevent it in the future.
Eric
Today I changed my Omni Pac Wireless 12 by a 120° sectorantenna. Unfortunatelly it seems damaged because with this sectorantenna, signalstrength was about 25 dbm less than with the Omni Pac Wireless 12. Therefore, I had to change back to an Omni Antenna. But this time I don´t use the Pac Wireless Omni but The Wimo Omni GP-2400-12. I have this Omni on several other locations and no probles with dying cm9s.
I ordered a new sectorantenne anyway. I´ll observe this new antenna-solution, perhaps it´s a failure of the Pac Wireless Antenna Design. If the new Omni will damage my cm9 too, I´ll try the ordered new sectorantenna.
here is another one ;
http://forum.mikrotik.com/viewtopic.php?t=8719
also using pacific omnis, if i go back in time, problem starts happening with using these omnis ,
like i mentioned in my topic, other cm9 cards are running fine for weeks on same tower, only CM9 going dead is the 2,4Ghz 10db Omni (wich is at highest point in tower )
we started oure network with cheap linksys WRT54G ( broadcom chipset ) , with 15db Omnis ( not pacific ) ,the are up and running for 3 years now and i dont see the problem there, also we use them a lot as client CPE’s ( with grid/panel 15db ) also no problems there.
what iám qurious about is, do you guys all use routerboard ?, i notiched that i have the problem from teh point we use routerboards , but could be
coincedence , other we us 1+Ghz pcboards(asus/via), also no problems there with dieing cards, all antennas there “stella doradus” sector and omnis.
we should make alist with mac numbers of died cm9/antenna type/brand used and pin out the bad setup/antenna/cm9 series generating these failures.
i will make an simple webpage doing this, or if someone can make such a page in minutes ( i need days ), please contact me.
like i mentioned in my topic, other cm9 cards are running fine for weeks on same tower, only CM9 going dead is the 2,4Ghz 10db Omni (wich is at highest point in tower )
Also a Pacific Wireless Omni ???
Yes, you won´t have this problem with a cheap linksys WRT54G (broadcom chipset). I have also some WRT54G with Omni (Pac Wireless 12) an no problem there. But to be honest, the broadcom chipset is very bad … very low receive sense. Only cm9s or similiar mini-pci cards with this aetheros chipset are affected. Perhaps because theire receive sensity is so good.
I don´t think that we need the MAC of the cm9s. A list of the affected Omnis that damagend a cm9 would be enough.
As I already wrote, yesterday I changed Pac Wireless 12 to GP-2400-12 at one affected location an I will observe this location now. If the station will run for 12 weeks without loosing the cm9, I would say that this GP-2400-12 will not kill your radio. By the way, the GP-2400-12 seems to receive signals a little better than the Pac Wireless 12, about 2 dbm.
Also a Pacific Wireless Omni ???
yes
regarding list of cm9 macs, is because i think it could be a problem of series CM9 cards too
this because lately a LOT of people have these dead card issues.
All right. Unfortunatelly, I put most my damaged cm9 into the trashcan. But here are three MACs of damaged cm9s and R52
CM9: 000B6B4D4311
CM9: 000B6B3759B4
R52: 000C420500DF
i’m busy working out the simple website to log all this data
but ok
here are my dead cards info ;
CM9 000B6B361222 / 2,4Ghz with 10db omni ( comet )
CM9 000B6B3611CD/ 2,4Ghz with 10db omni ( comet )
CM9 000B6B3611ED/ 2,4Ghz with new 12db omni ( comet )/ new routerboard /new cables / new pigtails
CM9 000B6B3610B9/ 2,4Ghz with 12db omni ( comet )
CM9 000B6B4DD259/ 2,4Ghz with 12db omni ( comet )
these cards all died after 1 minute to 2 weeks
last one i put in i didnt even enabled as AP in mikrotik, but already shows bad signals when scanning. ( i grouded evrything extra,didnt help/i isolated everything from tower,didnt helped, replaced evrything , didnt help )
only thing i didnt try, is another brand omni antenna.