ADF4360-1 Vtune voltage

Check the VCO core current. It should be set to 15 mA.

Using a non-specified VCO core power current changes the VCO vs. frequency characteristic completely.

Only the specified VCO core power current should be used for the ADF4360-x family, in this case 15 mA.

Core current is  5mA.  Can you elaborate on how this would affect the Vtune voltage / VCO core?

Thanks. 

An update:

I've tried all VCO core power settings (5mA, 10mA, 15mA, and 20mA).  Vtune did not change.  Any other thoughts?

Thanks,

Tim