What happens when the omnibearing selector (OBS) of a VOR station is rotated?

When the omnibearing selector (OBS) of a VOR station is rotated, it specifically allows the pilot to set and select a desired radial or course to or from the VOR station. The OBS directly influences the operation of the course deviation indicator (CDI), which includes the course deviation needle. As the OBS is turned, the selected course changes, and the CDI indicates whether the aircraft is on the desired course, to the left, or to the right of it. This functionality is essential for navigation, as it helps determine if the aircraft is tracking correctly toward its intended route. The ability to manipulate the OBS provides precise control over navigation with respect to the VOR signal being received. Thus, the movement of the OBS indeed correlates to changes in the reading on the course deviation needle, guiding pilots in their navigation decisions.