I have a 6 mile link that used to work perfectly. It has the complete Fresnel zone open, so no LOS issues here. We had a storm that took out one tower completely a few months ago and I have been fighting it ever since. ALL equipment on both ends has been replaced at least twice and without change to performance. I'm about to give up. I have attached a screenshot that shows what we are dealing with here. Any help would be greatly appreciated.

Here are the basics.
RB333AH on one end, Alix 2c3 on other, both running v3.30.
Fresh XR9s.
Both in AP mode.
freq 2432
10 MHz bw channel
Noise floor 91 to 92 dB both ends.
SNR 21 dB
Signal Strength 68 dBm
CCQ only about 30%
Tx/Rx rates stay at only 6m/2-6m/2
Packet loss is about 70%

What's going on?

I have a 6 mile link that used to work perfectly. It has the complete Fresnel zone open, so no LOS issues here. We had a storm that took out one tower completely a few months ago and I have been fighting it ever since. ALL equipment on both ends has been replaced at least twice and without change to performance. I'm about to give up. I have attached a screenshot that shows what we are dealing with here. Any help would be greatly appreciated.

Here are the basics.
RB333AH on one end, Alix 2c3 on other, both running v3.30.
Fresh XR9s.
Both in AP mode.
freq 2432
10 MHz bw channel
Noise floor 91 to 92 dB both ends.
SNR 21 dB
Signal Strength 68 dBm
CCQ only about 30%
Tx/Rx rates stay at only 6m/2-6m/2
Packet loss is about 70%

What's going on?

Did you replace the antennas? The coax cables including jumper cables and pigtails? Lightning suppression?

Any other radio equipment in the area that might be interfering? Like a broken paging system radio?

It might be worth it to get one of those inexpensive Airview9-ext Spectrum Analyzers and see if there is anything in band causing problems.

Something has to be killing those packets.

Tom

Yes, all antennas and pigtails have been replaced. We might say the original was hard to recognize! Good idea on the airview, I'll get one on the way. I do not use lightning suppression because of signal loss, been there done that...

There is a pager system running at 200 something MHz on one tower, but the other links on that tower seem to be OK. The other tower is way out in the country, and I own it, so no possibility there.

One thing I did think of, the ALIX is known for having problems with high powered cards. Could it be a possibility that the XR9 is under-volted on that board?? I was running a RB411 on that AP before the strike. Might be the next thing to check there...

Yes, all antennas and pigtails have been replaced. We might say the original was hard to recognize! Good idea on the airview, I'll get one on the way. I do not use lightning suppression because of signal loss, been there done that...

There is a pager system running at 200 something MHz on one tower, but the other links on that tower seem to be OK. The other tower is way out in the country, and I own it, so no possibility there.

One thing I did think of, the ALIX is known for having problems with high powered cards. Could it be a possibility that the XR9 is under-volted on that board?? I was running a RB411 on that AP before the strike. Might be the next thing to check there...

You always have to look at what has changed since it was working so of course try changing out the Alix for an RB411. It is also possible that the pager has changed since the storm and that is why I was thinking that the airview might help you find interference.

FWIW They run licensed paging near 900MHz in our area. They used licensed 900 just above and just below our unlicensed space but they have high enough power to cause problems.

Good luck and let us know what you find,

Tom

Hi there...

Tom's suggestions are good. Have you did a SCAN on the XR9(s) to see if you're getting and nearby pagers, etc? Also, is the problem on all the CPEs on 900 or just one?

What's at the user end of the link (noise floor, CCQ, signal)? Could be something at the user end like cordless phones, etc. ALso, you might want to double check all the physical connections, especially at the tower mounts, etc) as there could be some intermod products being generated.

Leon