Explanation: F1B FEC (Forward Error Correction) is a type of FSK (Frequency Shift Keying) digital mode. FSK is a *constant envelope* modulation scheme, meaning the amplitude of the radio frequency (RF) carrier remains constant, while its frequency shifts to encode data (mark and space tones). For a constant envelope mode like F1B, the RF power output from the transmitter should be constant throughout the transmission, assuming proper amplifier operation. Therefore, a power meter should indicate a steady output level. Operating between 225 and 250 watts for a 250-watt transmitter indicates proper, full-power operation. Option B is incorrect because FSK transmits a continuous carrier, shifting its frequency, rather than turning the power on and off. Option C is incorrect as an "S" meter measures *received* signal strength, not *transmitted* power, and its readings are typically in S-units, not watts. Option D describes a varying envelope mode (like AM or SSB), where power fluctuates with modulation, which is not characteristic of FSK.