🔍 Key Concepts

• Marine radio beacon purpose and typical use in navigation (older RDF/LOP systems) • The portion of the LF/MF (low and medium frequency) spectrum traditionally allocated to marine radiobeacons • Distinguish between general MF maritime bands (like 300 kHz–3 MHz) and the narrower band assigned just to radiobeacons

💭 Think About

• Which of these options looks like a relatively narrow slice of frequencies specifically reserved for a special-purpose service, rather than a broad communications band? • Think about whether marine radiobeacons need to be within the same band as VHF (very high frequency) or typical MF voice communications, or in a separate LF/MF band optimized for direction-finding. • Which ranges here fall entirely in the LF/MF region normally used for non-voice navigation aids rather than ship-ship voice or weather broadcasts?

✅ Before You Answer

• Verify which answer choice lies fully in the low/medium frequency region below traditional MF voice/DSC frequencies (around 2–3 MHz and up). • Check older navigation texts: marine radiobeacons supporting radio direction finding (RDF) are in a specific, relatively tight band, not spread too wide. • Eliminate any band that clearly extends into frequencies used for other services (like long-range MF communications) rather than fixed navigation beacons.