🔍 Key Concepts

• MF-DSC distress alerting and what DSC actually sends (digital selective calling vs voice) • The traditional MF radiotelephone distress frequency used for voice traffic • How DSC calling channels differ from follow‑on working frequencies

💭 Think About

• After a digital distress alert goes out on MF, what separate frequency has historically been used for actual voice MAYDAY traffic in the MF band? • Which of the listed options is known as the international radiotelephone distress and calling frequency, not the DSC channel itself? • Among the answers, can you identify which are DSC control channels and which are intended for voice communication?

✅ Before You Answer

• Identify which option is the international MF radiotelephone distress and calling frequency used for voice MAYDAY traffic. • Confirm which frequency, among the options, is specifically designated as an MF-DSC calling channel rather than a voice channel. • Make sure the frequency you pick is associated with voice follow‑up communication after a DSC alert, not with sending the digital alert itself.