🔍 Key Concepts

• MF/HF NBDP (Narrow Band Direct Printing) operation in F1B FEC mode • Behavior of RF power output in continuous, automated digital modes • Difference between transmit power indication and receive signal indication (S-meter)

💭 Think About

• In F1B FEC mode, is the transmitter keyed only when you press keys, or is the emission more continuous during a transmission sequence? • For a properly operating 250W MF/HF transmitter, should the RF power meter show steady power, no power, or rapidly varying power while FEC data is being sent? • Which meter (RF power meter vs S-meter) represents your own transmitter’s output rather than received signals from other stations?

✅ Before You Answer

• Confirm that F1B FEC is a digital, keyed carrier emission used for NBDP, not a voice mode. • Identify which choice refers to transmit RF power output, not received signal strength. • Decide whether proper digital FEC operation should show constant carrier power or on/off power changes that follow the data pattern.