When GPS doesn't track satelites

There are 2 sites (radio towers) where I have 2 CMM-micro.
In one case the GPS sees around 8 satelites with out never being able to track them (no sync). In the second case GPS is able to track up to 3 satelites but sometimes it looses them and the network goes down creating a lot of problems.
I’ve tryed to change every part of the system (CMM, cable, antenna and position of the antenna). I end up thinking that it’s a problem of RF interference as in these sites there are many different radios installed and I’ve never had similar problems in other places where I installed CMMs with less RF in the air.
Do you think radio interference can be the problem ?
And if this is the problem, what to do?
It’s not unusual to install Canopy system on radio towers with high density of antennas. And it’s strange that to reduce Canopy self interference I have to use a system that results to be not reliable in presence of high RF interference !!
I see that in CMMmicro there is a RJ11 conector, I thought that I could use it to get the sync from one Canopy (BH slave) and provide it to the others but I understand that it’s not working in the present version.
Have any of you faced this problem and how you solve it ?

When you log into the micro does it say anything about the antenna connection?

Have you measured the voltage from the receiver? Should be 5 volts

What about the current? Should be 26 mA.

How long is the GPS antenna cable from the micro to the antenna?

If you have a lot of noise around 1.2-1.5 GHz then yes you may be experiencing interference. This is rare however we have seen it.

Has this site ever had GPS sync or is it a new install?

http://motorola.canopywireless.com/supp … /index.php?

Make sure the GPS antena in completly straight; use a level is possible.

This should resolve the problem.
It happend to me a couple of months ago.

Can you track with a hand held GPS? Does it fail near the current GPS locations, but would elsewhere in the compound?

You might try mounting a SyncPipe at height with a direct connection to one of your Canopy Radios. If it is stable, then you need only use one of their splitters to feed the site.