Clients drop when it rains

I have two clients about 4 miles from the tower. When it rains there signal drops. They are about 500 feet from each other and are using a 900mhz non-connectorized Sm with a cushcraft 13dbi yagi. The connection is solid when it’s nice but as soon as it rains the go offline and the sm seems to hang. On the status page the SM says registering and hangs there. We have replaced the sm, yagi and even tested it on our laptop and still the same result.

Any ideas what might cause this anomally?

How many trees between the AP and Sms? When leaves get wet you will loose a few dB.

Can you provide more info, software, scheduling, power levels, jitter etc…

It sounds like the links are on the edge of connectivity. If the fresnel zone is pushing through any foilage, then that would potientally explain the additional pathloss, as sinned123 suggested.

I figured it out; they say these non-connectorized SM’s are weather hardened. I beg to differ, we found that water was collecting in the base of the SM where the cable RJ-45 connection is, causing the SM to fill with water thus shorting it out and coming back online after the heavy rain stopped and had drained out. I found water in every SM yesterday of clients that were losing connection when it rained. Unbelievable!

We fixed the issue yesterday by using waterproofing, self-adhering tape on the base of the SM that snaps in. We used this on five customers who were having the same issue and plan on doing it to all customers with non-connectorized SM’s. All of the base covers for the SM’s were securely attached, but filled with water. After doing this yesterday, it was put to the test last night when it rained hard and not one of these clients dropped at all. Another wonderful headache fixed.

Thanks people for the quick responses.


Interesting - I don’t think we have ever had that problem.

You need to make sure that you leave a drip loop so that the water cannot seep into the bottom of the SM.

I have had issues in the rain, but always assumed foliage loss of dB. (those I have issues with are marginal anyway).

Are you saying the cover fills with water? Even if full it doesn’t seem to me it would reach and cover the CAT5 connector which is recessed upwards?

Maybe drilling a small drain hole in the bottom of the cover would suffice?

That’s a new one here too. hmmmm.