🔍 Key Concepts

• MF/HF radiotelephone emissions modes such as J3E (single-sideband, suppressed carrier telephony) • Data/telex modes used for SITOR/NBDP (narrow‑band direct printing), such as F1B/J2B • The difference between voice radiotelephony and telex/data operations when calling a coast station

💭 Think About

• Ask yourself: when you make a standard spoken voice call over MF/HF, is the radio using a telephony mode or a telex/data mode? • Look at which emission designators are associated with SITOR/NBDP – are those normally used for printing text or for spoken words? • Identify which option clearly describes a mode used specifically for voice and which options are talking about SITOR/NBDP or ARQ/FEC data choices.

✅ Before You Answer

• Verify which emission designator J3E corresponds to (voice SSB telephony vs telex). • Verify which emission designators F1B/J2B are tied to NBDP/SITOR operations (FEC/ARQ). • Confirm that a routine MF/HF voice call to a coast station uses the standard SSB telephony mode, not a narrow‑band direct printing data mode.