Subelement K: K – Aircraft— Topic 69: VHF Omnidirectional Range (VOR)
Question 3-69K2
Element 3 (GROL)The rate that the transmitted VOR variable signal rotates is equivalent to how many revolutions per second?
Explanation
The VOR (VHF Omnidirectional Range) navigation system determines an aircraft's bearing by comparing the phase of two 30 Hz signals. One is a reference signal, omnidirectional and constant in phase. The other is a variable signal, created by a rotating directional antenna pattern, which completes 30 full rotations per second.
As this variable signal rotates, its phase changes relative to the reference signal. An aircraft's receiver measures this phase difference, which directly translates into its magnetic bearing from the VOR station. Therefore, the transmitted VOR variable signal rotates at a rate of 30 revolutions per second.
Options A, C, and D are incorrect as they do not correspond to the internationally standardized rotation rate for VOR variable signals.
Related Questions
3-68K6 The majority of airborne Distance Measuring Equipment systems automatically tune their transmitter and receiver frequencies to the paired __ / __ channel.3-69K1 All directions associated with a VOR station are related to:3-69K3 What is the frequency range of the ground-based Very-high-frequency Omnidirectional Range (VOR) stations used for aircraft navigation?3-69K4 Lines drawn from the VOR station in a particular magnetic direction are:3-69K5 The amplitude modulated variable phase signal and the frequency modulated reference phase signal of a Very-high-frequency Omnidirectional Range (VOR) station used for aircraft navigation are synchronized so that both signals are in phase with each other at ____________ of the VOR station.