PTP throughput/alignment question

I have a link (PTP400 Lite) that is 12 miles long and the heights are 120ft and 140ft. According to the Link Estimator the terrain is pretty much flat and has line of sight. The vegetation in the area is somewhat dense but no trees are above 45ft or so. Now my question is what is could cause me to only get 1.5MB aggregate through the link? Everything seems to be aimed correctly, we get good solid, high pitch tone and the availability of the link is 99.98x. If the link has line of sight I would assume much higher throughput. Is my alignment just off or is there some other setting I should check?

Since you used the alignment tone, this means that you used the installation agent. Make sure that you disarm both radios after the alignment is complete.

When you use the installation agent, the radios default the the lowest possible modulation level for alignment purposes. In the lowest modulation level, minimal data can be passed from side to side, just enough to allow you to ping the remote radio, or log in to its web interface for configuration purposes.

Double check and make sure the radios are out of alignment mode. Once they are out of alignment mode, the link will attempt to achieve the modulation level that you have configured in the Max Modulation Level parameter.

If you have taken both units out of installation mode, what do you have your Max Modulation Level configured to? What about Max Tx power? What is the RSL/RSSI reported to be from both radios?

I did disarm both ends and they are both at the highest modulation 64QAM 7/8 i believe. I dont know the transmit power off top of my head but I don’t believe it was changed out of the box so the default most likely.