Page 1 of 1

Big problem with CM9

Posted: Mon May 29, 2006 1:09 pm
by jkljajic
I have big problem with atheros CM9 and WRAP board. When I put CM9 to work like client it's work fine, but when I put it to work like AP CM9 work fine approximately 10-24 hours, and than CM9 work but signal is wary low and he acts like do not have any external antenna, when I try to scan AP I get no AP in scan list. but when I put card I scan and get 10 AP and from 25 km distance. I try to change WRAP board cable and antenna but same stuff is happened again. I am burn 3 CM9 card, but when I put PRISM 2.5 card its work normal.

Posted: Mon May 29, 2006 11:30 pm
by cmb
also check out http://forum.mikrotik.com//viewtopic.php?t=8719

I HAVE SAME PROBLEM! INPUT GOES DEAD.

Posted: Mon May 29, 2006 11:39 pm
by cmb
I have exactly exactly same problem!

- CM9 work fine approximately 10-24 hours, and than CM9 work but signal is wary low
- SR2 work fine approximately 10-24 hours, and than CM9 work but signal is wary low
- COMPEX work fine approximately 10-24 hours, and than CM9 work but signal is wary low
- SENAO work fine approximately 10-24 hours, and than CM9 work but signal is wary low


example: -64 signal will get -88 a -90

when replacing the card it goes back to -64 for a couple of hours or days!

Posted: Mon May 29, 2006 11:50 pm
by changeip
what is the temperature range these are installed in? Maybe its a heat issue ruining the chips.

Posted: Tue May 30, 2006 1:49 am
by djape
I swear that this is the last time I'm writing this :)

Omni and cm9 is duyin' on stormy weather!
Prism doesn't have that problem!
So, try using sector or panel antennas if you use cm9.
It's just the problem with the omni antenna design. You can't do anything about it, it's the way it is.
Let me guess :) You want (for small amount of money I assume) to have 360 degrees good signal, 100+ client and to work superb and without problems?
IN YOUR DREAMS! :D

Cheers all...

Posted: Tue May 30, 2006 2:37 pm
by bushy
Maybe in omnis the centre pin is not connected to the outer sheath at all....in directionals that i have opened the centre core is joined to the outer sheath by one of the dipole arms.I suppose this would stop static building and damaging the cm9

Posted: Tue May 30, 2006 5:39 pm
by jober
I swear that this is the last time I'm writing this :)

Omni and cm9 is duyin' on stormy weather!
Prism doesn't have that problem!
So, try using sector or panel antennas if you use cm9.
It's just the problem with the omni antenna design. You can't do anything about it, it's the way it is.
Let me guess :) You want (for small amount of money I assume) to have 360 degrees good signal, 100+ client and to work superb and without problems?
IN YOUR DREAMS! :D

Cheers all...
I don't understand this phenomenon with the omni's but I have to add that a friend of mine is having the same problem. He keeps asking me WHY? and I can't tell him because I have never had that problem. But then again I don't use any omni's over 40 feet up.
Just about all I use is sectors, panels, grids and solid dishes.

So, are you saying that the design of an omni is going to kill the card by design or is it that the design of the omni attracts lightning and static discharges from the air and that is what is killing the cards. ????

"Inquiring minds want to know"

Posted: Tue May 30, 2006 5:58 pm
by maxfava
May be the different manufactoring between the omni and the sector is an issue.
I have encountered the same problem but with two different omni.
on 1 omni works fine on the other not.

Posted: Tue May 30, 2006 8:38 pm
by pinotage
I definitely have had this problem too. Where I had an omni with clear 360 degree LOS and an atheros based card, this seemed to happen, only matter of time. I replace all these cards with the prism one's, and voila, no problems again.

Then the other scenario where I have an omni against a pole, thus acting as a sort of sector antenna, with SR2's in, no problem up to now, 1 year running SR2's.

Posted: Tue May 30, 2006 8:51 pm
by jober
The friend I was talking about grounded the pole that the omni is on and he hasn't had the problem again.
I had told him to ground the thing with a copper wire all the way down the silo to a long grounding rod. He did it but he used some lighter gauge wire to the ground rod. If it works I guess that's all that matters.

Maybe some people are not grounding things as good as they thing.
Or, Maybe some of the omni's are that easy to ground.

I think it would be a good idea to make a list of omni's that are killing the cards.

Posted: Wed May 31, 2006 6:31 am
by sten
It is probably a bad idea for there to be a difference in charge between antenna which, without sufficient ability to get rid of the overcharge will discharge into a radio, motherboard and powersupply.

Those of you, who choose to ignore the fact that radios is extremely sensitive type of equipment, will of course have another opportunity to whine about how terrible brand X is on your favourite forum/mailinglist.