900 AP Power down 15DB

About a week ago all 900Mhz subscribers on a sector received power levels dropped by about 15db. Also on the AP what is received from the SM’s is down about 15db. We put the AP in SM mode an did a survey and the noise floor looks good. Could this be an AP going bad? Or is it the sector antenna? All the connections between the radio, bandpass filter, and antenna look good.

Any help would be appreciated.


Thanks all.

  1. Plug in a new antenna directly to the motorola pigtail. If the problem resolves itself, you have narrowed it down to one of the components that isn’t the AP.

    or

    2. Plug in a new AP. If the problem resolves itself, it was the AP.

    See how easy that is? :slight_smile:

When faced with similar problems, I’ve actually zip-tied a Superpass 900 antenna on top of an IT Elite 900 sector just for testing. We eventually found that there were too many trees growing in the way, but this was a gradual loss of dB and not an instant 15 dB loss.

When you have seen this problem is the most likely failure on the AP or the Sector antenna. I’m not an antenna expert but what can go wrong with them besides a lightning hit frying it. I could see an AP failing because of is is a digital device that could fail many ways.

Thanks for your help.


twinkletoes wrote:
When faced with similar problems, I’ve actually zip-tied a Superpass 900 antenna on top of an IT Elite 900 sector just for testing. We eventually found that there were too many trees growing in the way, but this was a gradual loss of dB and not an instant 15 dB loss.

Since it’s both Tx and Rx I would suspect water intrusion into the antenna or connectors.

The suggestion to try another radio is what I would do. If the problem remains, then I would look for water intrusion into the connectors or antenna.

FYI for all who replied.

We fixed the signal loss problem yesterday and found the problem to be the bandpass filter. We removed the filter and are now seeing the best signals we have ever seen, about 25db up from during the problem, and about 9 db better than with the filter before the problem occurred.

Thanks all.

I see you guys are using 900 Mhz? You should check out the 17.5 and 14.5 Dbi Yagi antenna. by KP Performance

www.kpperformance.ca



Take care