Limited by the wireless conditions

I have a pair of older ptp 600's that I am trying to resurrect for a temporary (3 month) link.  I have them back to back on the bench, with the proper attenuation, and getting "limited by the wireless conditions" for my receive modulation detail.  I have tried 2 cables.  Anyone have any ideas on what I may be overlooking or do I have a bad transmitter?

Check with the spectrum analyzer what frequency is using and what are the conditions.
What modulation mode (rx and tx) are you getting now? Which Channel Bandwidth are you using?

What received signal level do you have? Ideally, something around -45 dBm.

Is this inside of a room with concrete walls, metal building that could effect multipath etc?