🔍 Key Concepts

• MF-HF (Medium Frequency–High Frequency) antennas on ships are usually whip antennas matched by an antenna coupler/tuner • The effective electrical length of an MF-HF antenna is important for tuning across 2–30 MHz • Most shipboard MF-HF systems are designed to work with a relatively short vertical radiator rather than extremely long wires

💭 Think About

• Think about what kind of temporary antenna your MF-HF tuner/coupler can successfully match without major retuning or redesign. • Which option best resembles the vertical whip that was lost—in both orientation and approximate length? • For general MF-HF communications on a GMDSS ship set, what typical physical length of antenna do manufacturers specify in their installation manuals?

✅ Before You Answer

• Check which answer mentions using the antenna coupler/tuner properly, as in a real ship installation. • Verify which length range (in feet) is most commonly associated with shipboard MF-HF whips in manufacturer guidelines. • Eliminate options that describe antennas that are unusually short or excessively long for normal MF-HF marine transceiver installations.