FCC General Radiotelephone Operator License GROL Element 1 Practice Test 2026 – Comprehensive Exam Prep

Vessel traffic lists sent from high seas shore stations need to be received reliably over long distances, so the best combination uses a modulation that is efficient for HF radio and an error-control method that can correct mistakes without needing a retransmission. Single-sideband modulation (SSB) is preferred on HF because it uses less bandwidth and performs well over long ranges, making it ideal for shore-to-ship transmissions. Forward error correction (FEC) adds redundancy to the data so the receiver can detect and correct errors introduced by noise or fading, which is common on the high seas. AM would be less efficient and more susceptible to noise, while VHF-FM is limited to shorter, line-of-sight distances. ARQ relies on acknowledgments and a return path, which is not practical for one-way shore-to-ship broadcasting of lists. So the combination of SSB and FEC is the appropriate choice.