CMM Micro not Syncing...HELP

CMM Micro is not obtaining a sync. It has 10 plus visible satellite but not tracking any. Tested a known good CMM Micro and GPS antenna from another tower site with the same results. Sometimes it picks up satellites and starts syncing for a few hours, then it will lose it all together for several hours.

Does anyone know if Amber Alert radios would cause a problem or interference? Any ideas???

Try moving the antenna so it has the best possible view of the southern sky

The GPS antenna is on a 60’ tower on top of a 12 story building (the tallest in the city) so there is a clear view. This has has been working for us for several years. To troubleshoot we have even taken a new CMM, 100’ cable and antenna from a working environment and placed it on the tower, same thing 7-10 visible satellites but none tracked. Took the equipment back to the office and it works perfectly. The only other equipment on the tower is FM radio, amber alert, and city equipment. We are really at a loss. Does anybody know how long the the last mile gear holds sync after it loses GPS pulse? Any suggstions would be appreciated.

LMG CTM will generate sync for approximately a day.

Can you mount the GPS antenna off the side of the building or shield it behind the elevator house?

change gps antenna location, lower it down and separate it more from the tower

dfisher wrote:
we have even taken a new CMM, 100' cable and antenna from a working environment

Isn't the max distance for a GPS antenna 30m/98 feet? Kinda riding the line there

I’ve actualy just had a similar problem and wondering if someone who has used a few more CMM’s can check my logic. I had a site running off the CMM fine for about 4 weeks past install then a couple of days aog we lost all sync, the CMM still reports that it can see satellites but can’t manage to track them, under the GPS status tab it reports the antenna connection as “under current” I read that as the signal degrades to much between the GPS antenna and the CMM to be of use in sync possibly because of a fault with the antenna or cabling. That sounds about right to others or has it been seen with a different sort of fault as well?

To answer my own query for if anyone else finds a similar error, in this case it was cuased by a bad connection on the GPS antenna.

mimbanis wrote:
under the GPS status tab it reports the antenna connection as "under current"

That usually means that the LMR your running has to much resistance.

Antenna connection should show ‘OK’ not ‘under current’.