On F-16 block 60 the APG-80 radar is slightly slanted back to reduce the RCS of the aircraft (similar design methods is also used on F-18E/F, F-2, F-22, F-35, J-20..etc) . But on F-16V Block 70, the APG-83 radar is designed to be perpendicular to the direction of travel, so the RCS is much higher head on. What is the reason for this backward change in design?
F-16 block 60 with slanted radome
APG-83 with straight antenna face
F-16 block 60 with slanted radome

APG-83 with straight antenna face
