🔍 Key Concepts

• F1B FEC (NBDP/telex) transmission characteristics on MF/HF • Normal RF power behavior for keying/mark-space digital modes • Difference between transmit power indications and receive signal (S-meter) indications

💭 Think About

• Think about what a properly tuned MF/HF NBDP installation should look like on the RF power and SWR meters when you are transmitting a steady stream of telex characters. • Ask yourself which indication describes receive conditions rather than transmit operation, and whether the question is asking about the transmitter or the receiver. • Consider whether a digital FEC signal in F1B mode should show steady power, varying power, or signs of high reflected power/SWR problems during normal transmission.

✅ Before You Answer

• Identify which options describe transmit power and SWR versus received signal strength; focus only on transmit behavior for this question. • Check whether the described forward and reflected power would be acceptable for efficient antenna tuning on a 150-watt MF/HF system. • Decide whether a properly functioning F1B FEC transmitter should show constant RF output near rated power or a rapidly fluctuating output from zero to full power.