Hello,

we have now the third card that has a saturated receiver amplifier. First we had a non-dc-grounded antenna and no surge protection. After the second failed R52H card, we replaced the antenna by a dc-grounded one and installed a quarterwave surge protection. Now, after two weeks the RX signal strengts are really bad and some clients are not able to connect at all.

so this is the third R52H card that failed at the location. We had a Senao card there before that worked 2 years without any problems (the tower was not grounded at all!)

Are the R52H cards that bad (quality)?

maybe i should mention that we're using the default TX power

Are you using omni antenna?

yes, its a omni .... With 12dbi gain

See this thread for solution.

http://forum.mikrotik.com/viewtopic.php?f=7&t=9734

I dont think that this will really fix it.. we are already using a dc-grounded omni and have a extra Quarterwave Surge Protection installed ... so it's secured twice but the diversity switch just lost function ...

One interesting thing: All times the cards were blown, the whole ROS did a reboot (we are using a Alix board on this installaton) ...