Subelement F: Maritime Safety Information (M.S.I.)— Topic :
Question 38F2
Element 7R (GMDSS-RO)How can reception of certain NAVTEX broadcasts be prevented?
Explanation
NAVTEX receivers are designed with sophisticated filtering capabilities to manage the volume of incoming messages. Users can program the receiver to reject broadcasts from specific transmitting stations (identified by their unique B1 character). Additionally, unwanted message categories (identified by their B2 character, e.g., navigational warnings, meteorological forecasts, search and rescue information, or test messages) can be deselected, preventing their reception and display. This allows operators to customize the information received to their specific needs and geographic area.
Options B, C, and D are incorrect. NAVTEX operates continuously, 24/7, on frequencies (like 518 kHz) that are not limited to daytime operation; in fact, MF signals often have increased range at night due to skywave propagation. While broadcast schedules exist, coordinating with them only informs when broadcasts occur, it doesn't prevent reception of unwanted messages. Automatic receiver desensitization is not a standard feature for filtering NAVTEX and would generally be an undesirable reduction in sensitivity, not a user-controlled method to prevent specific broadcasts.
Related Questions
37F6 What is the transmitting range of most NAVTEX stations?38F1 How is a NAVTEX receiver programmed to reject certain messages?38F3 Which of the following statements is true?38F4 What means are used to prevent the reception of unwanted broadcasts by vessels utilizing the NAVTEX system?38F5 What statement is true regarding the control the operator can exercise over the NAVTEX receiver's operation?