Subelement C: Satellite Systems— Topic :
Question 31C6
Element 9 (GMDSS Maintainer)The antenna tries to initialize then points straight up and stops. What is the most likely problem?
Explanation
Antenna control systems perform an initialization sequence to establish a known starting orientation. Pointing straight up (zenith) is often part of this process, after which the system seeks to find a true "level" (0 degrees elevation) reference. A defective level platform sensor prevents the system from accurately determining its horizontal baseline. Unable to complete this crucial calibration step after moving to zenith, the control system halts, as it cannot establish an accurate operational reference point for subsequent commands.
A and B are incorrect because defective motors would likely result in no movement or uncontrolled movement, not a specific initialization sequence followed by a stop at a particular point. D is incorrect as an I.F. amplifier is a component of a radio receiver and unrelated to antenna mechanical positioning.
Related Questions
31C4 The antenna goes past the AZ EL of the satellite but does not initialize but you can manually point the antenna at the satellite and acquire signal. What is the most likely problem?31C5 The antenna creeps up and down after initialization. What action would you take?32C1 What action should be taken if an Inmarsat Fleet Broadband antenna continuously changes azimuth after initialization?32C2 What condition would cause failure of an Inmarsat-C terminal to power up when AC voltage is present at the input terminals of the power supply?32C3 What condition would cause an IP connection failure between a technician’s laptop and an Inmarsat Fleet Broadband terminal?