Diminishing Receive Power & Uplink Power

When first installed the 450i 900 MHz with the stock 12 dbi yagi the downlink was 13.x and the uplink was 4.x

That speed was consistent until something happened.  Not sure what happened but the link became inconsistent and then a drop in receive power. 

The first thing that came to mind was noise but after many scans I ruled that out.

Noise floor was the same but my receive power was down.

Had been looking for a pair of the 17.5 yagi but never found two for sale so I ended up purchasing the five pack.

After installing the 17.5 yagi on the SM I was able to achieve a link aggregate of 31.x with a downlink of 26.x

Then a drop in receive power.

The downlink was back to 13.x the noise floor was still the same.

Then another drop in receive power.

The downlink is now 9.x and the uplink is now 1.x

Have run scan after scan after scan.  The noise floor appears to be the same.

Have check alignment and the radios appear to be in the same position.

What has happened?

What can I do to fix this?

Is this an equipment problem?

Any help in resolving this issue would be most appreciated.

Stay Safe.

The most obvious reason for this kind of problem is water in coax cables.

Hi George.

Ugg...

Thought I was using the good stuff. ( Shireen outdoor shielded CAT5e )

All of the connection points are inside (Radio, 600SS) cases so how did it get in there?  (cut in cable?)

Any way to I can verify?

Any recomendataions on what I should use?

I'm assuming its some sort of shielded, gel filled, uv cat5e cable.

Did I say Ugg.

Stay Safe

opps

You said coax.

So your saying between the radio and the antenna, correct?

Yup

Thanks for the info.

Will check for water intrusion ASAP.

If I find no water then what should I look for?