We have been trying to generate a 5GHz RF carrier signal with the EVAL-ADF4372, but we haven't been able to get any output. Our setup is almost exactly like the one in the manual: There's an SDP-S board connected to the main board, a laptop running ACE connected to the SDP-S, a 6V DC power supply connected to the banana connectors, a 50 Ohm terminator on RF16P, and a DSOS604A oscilloscope (rated for 6GHz 20GSa/s) connected to RF16N. The only difference is there's no external reference, but R19 and R20 are still connected, so it should be using the on-board 100 MHz reference anyway.
The software settings are also exactly the same. We've also tried turning on x2 Enable and turning the frequency down to 2.5 GHz.
Reading the current VCO frequency back via ACE shows that it's outputting 5GHz, and the power supply is showing a current draw of 0.3-0.4A, yet we see nothing on the oscilloscope. It's exactly the same with 1GHz, 2GHz, 6GHz, and a separate pair of oscillator/SDP-S boards.