Hey all,
first time poster here and unfortunately I wish I weren’t because it’s usually bad news 
Besides interference what are some causes to have random customers down on a particular AP. We are running 900 mghz AP’s with a cmm micro. As of last night we have been experiencing random downtime and the eventlog in the AP is showing loss of GPS sync then re-aquire of GPS sync. We physically checked to GPS unit and it appears to be fine. In the event log of the CMM it doesn’t show anything as far as loss of sync. All the sattelites are being tracked. So it’s kind of a mystery.
Any thoughts or ideas would be appreciated.
Thanks,
Phil
Welcome to the forum. Spend some time going through the posts, there is alot of good info.
Loss of GPS on all AP’s is generally related to cabling, or position of the GPS antenna.
Check the cable for water intrusion, and move the antenna so that it has a better view of the sky.
Also, what type and length is the GPS antenna cable? Wrong impedance or a cable that is too long can be a problem.
Hopefully you have a spare cmm, cable, and antenna on hand…
Loss of sync on a few AP’s is usually related to the cable from the CMM to the AP. If you are not using shielded cable and you are on a noisy tower you can get alot of intermittent errors.
hope that helps.
Do you have a cable in the timing port of the radio running down to the bottom of the tower? If YES. You are are picking up noise on pins 5 and 6 of the timing cable. I ran into this on multiple towers. It took a escalation at Motorola to a senior tech who remembered seeing this one time.
The fix is to solder a 10K-Ohm, 1/4 watt Resister between pin 5 and 6. This will put the noise to the ground and allow GPS Sync. You can get the Resister at your local Radio Shack.
What I did was go ahead and terminate the timing cable with a RJ11 end. Get a Female RJ11 connector to plug into the end of the cable and solder ping 5 and 6 together with the Resister making the connection. This will allow you to also make a reset plug that can connect onto the cable in the event you need to reset the radio.
Well, seeing that he mentioned having a CMM Micro, it is unlikely that he is also using a timing cable.
My guess is that the issue is with the GPS Cable. I have found this to be Canopy’s Achilles heel as well as one of its strong points.
The cable is extremely prone to giving issues and once the CMM loses GPS, all your APs stop transmitting and all your clients on that tower are down.
In my opinion, the CMM should also include a factory crimped GPS cable so as to minimise issues with it.
vanilla wrote: Well, seeing that he mentioned having a CMM Micro, it is unlikely that he is also using a timing cable.
My guess is that the issue is with the GPS Cable. I have found this to be Canopy's Achilles heel as well as one of its strong points.
The cable is extremely prone to giving issues and once the CMM loses GPS, all your APs stop transmitting and all your clients on that tower are down.
In my opinion, the CMM should also include a factory crimped GPS cable so as to minimise issues with it.
If the cable is connected to the radio and not connected to the old style CMM that used the cable, you are prone to picking up noise on the pins mentioned above. I have seen it at both towers that are in noisy areas and one remote that doesn't have another tower for 5 miles around it. Just something to look for.