When checking the sensitivity of a VOR receiver, what is the acceptable range of degrees in course change when the OBS is rotated to shift the CDI from center to the last dot?

When checking the sensitivity of a VOR receiver, the acceptable range for the course change measured in degrees when the Omnidirectional Bearing Selector (OBS) is rotated to move the Course Deviation Indicator (CDI) from the center to the last dot is indeed between 10-12 degrees.

This range indicates how finely the VOR receiver can detect changes in the aircraft's position relative to the selected radial. A course change within this range signifies that the VOR system is functioning correctly, providing an indication that the instrument can accurately guide the pilot in navigating along the desired path. The last dot represents the threshold where the deviation from the selected course becomes significant, and a change of 10-12 degrees ensures that the CDI remains responsive, essential for maintaining awareness of the aircraft's navigation relative to the desired course. This standard ensures pilots can rely on their VOR navigation system for precision in instrument flying conditions.