900 AES Issues

We have a 900 MHz link that is right at ½ Mile. When I do a Spectrum analysis on the SM with the AP disabled I have a noise floor across the whole range of around -90. When we fire both radios up (both with 8.2.7 AES) we get about a -71 power level. The link will stay up for about 5 -15 min then drop for 2 – 5 min and it will cycle this way all day. We have replaced both radios and antennas and still have the same problem. Ping time are good and stable.

Any ideas?

there is known flaws with 8.2.7, try 8.2.4 or 8.2. or if there P9 boards roll those suckers back to 7.3.6 solid as a rock