At which position are the amplitude modulated variable phase signal and the frequency modulated reference phase signal of a VOR station in phase with each other?

In the context of VOR (VHF Omnidirectional Range) signals used in aviation, the amplitude modulated variable phase signal and the frequency modulated reference phase signal will be in phase at 360 degrees North. This is because 360 degrees represents a complete rotation back to the starting point, which is essentially the same as 0 degrees North.

As a result of the VOR system's design, the reference phase signal serves as a baseline, while the variable phase signal changes to reflect the aircraft's position relative to the VOR station. When the variable phase signal is in phase with the reference phase, it indicates that the aircraft is positioned directly on the radial associated with that phase angle. Thus, the signals aligning at 360 degrees reflects that the aircraft is directly over the VOR station or on the intended course, establishing a clear and accurate navigational reference.