Subelement D: Other Equipment— Topic 24: NAVTEX
Question 1-24D6
Element 1 (MROP)What is the transmitting range of most NAVTEX stations?
Explanation
NAVTEX stations operate on medium frequencies (MF), primarily 518 kHz for international broadcasts. MF signals propagate effectively via groundwave, which means they follow the curvature of the Earth and are not limited to line-of-sight. This groundwave propagation provides reliable coverage well beyond what is possible with VHF/UHF frequencies.
A typical groundwave range for NAVTEX is 200-400 nautical miles (360-720 km), allowing it to provide crucial maritime safety information to vessels offshore. Option A is too short for this essential service. Option B, while potentially achievable at night via skywave, is not the reliable daytime groundwave range for which NAVTEX is designed. Option D describes line-of-sight propagation, characteristic of VHF/UHF frequencies, which NAVTEX does not use.
Related Questions
1-24D4 What means are used to prevent the reception of unwanted broadcasts by vessels utilizing the NAVTEX system?1-24D5 When do NAVTEX broadcasts typically achieve maximum transmitting range?1-2A1 Which commercial radio operator license is required to operate a fixed-tuned ship RADAR station with external controls?1-2A2 When is a Marine Radio Operator Permit or higher license required for aircraft communications?1-2A3 Which of the following persons are ineligible to be issued a commercial radio operator license?