Thank you very much.
As usual your support is superb.
Your guide help me a lot, actually I quickly zeroed on the reason following your method. A faulty external relay to the D4D.
The D4D works perfectly when got rid of it.
73 de Pedro, LU7DID
PS: Sensitivity is good enough! My D4D rans day in and day out the receiver part of my FT8 beacon/monitoring station completely flawless, out of a rigid dipole routinely reports stations around the globe and daily most stations at the regional (1000-2000 Km distance).
Dr. Pedro E. Colla (LU7DZ)