Which of these digital modes has the narrowest bandwidth?
The correct answer is C: FT8. Which of these digital modes has the narrowest bandwidth is FT8. FT8 uses only about 50 Hz bandwidth, making it the narrowest. For amateur radio operators, this is important for weak signal operation. Understanding this helps when selecting digital modes.
Exam Tip
Narrowest bandwidth digital mode = FT8. Think 'F'T8 = 'F'ifty Hz (very narrow). FT8 uses only about 50 Hz bandwidth, making it the narrowest. Not MFSK16, not 170 Hz RTTY, not PACTOR IV - just FT8.
Memory Aid
"Narrowest bandwidth digital mode = FT8. Think 'F'T8 = 'F'ifty Hz. FT8 uses only about 50 Hz bandwidth, making it the narrowest. Important for weak signal operation."
Real-World Application
Digital mode bandwidth comparison: FT8 uses only about 50 Hz bandwidth, making it the narrowest. MFSK16 uses about 316 Hz, 170 Hz shift RTTY uses about 250 Hz, and PACTOR IV uses several hundred Hz. FT8 is designed for weak signal work with minimal bandwidth. This is the mode - FT8 has the narrowest bandwidth.
Key Concepts
Why Other Options Are Wrong
Option A (MFSK16): Incorrect. MFSK16 has wider bandwidth than FT8 - FT8 is narrower. MFSK16 isn't the narrowest.
Option B (170 Hz shift, 45-baud RTTY): Incorrect. 170 Hz shift RTTY has wider bandwidth than FT8 - FT8 is narrower. 170 Hz RTTY isn't the narrowest.
Option D (PACTOR IV): Incorrect. PACTOR IV has wider bandwidth than FT8 - FT8 is narrower. PACTOR IV isn't the narrowest.
题目解析
The correct answer is C: FT8. Which of these digital modes has the narrowest bandwidth is FT8. FT8 uses only about 50 Hz bandwidth, making it the narrowest. For amateur radio operators, this is important for weak signal operation. Understanding this helps when selecting digital modes.
考试技巧
Narrowest bandwidth digital mode = FT8. Think 'F'T8 = 'F'ifty Hz (very narrow). FT8 uses only about 50 Hz bandwidth, making it the narrowest. Not MFSK16, not 170 Hz RTTY, not PACTOR IV - just FT8.
记忆口诀
Narrowest bandwidth digital mode = FT8. Think 'F'T8 = 'F'ifty Hz. FT8 uses only about 50 Hz bandwidth, making it the narrowest. Important for weak signal operation.
实际应用示例
Digital mode bandwidth comparison: FT8 uses only about 50 Hz bandwidth, making it the narrowest. MFSK16 uses about 316 Hz, 170 Hz shift RTTY uses about 250 Hz, and PACTOR IV uses several hundred Hz. FT8 is designed for weak signal work with minimal bandwidth. This is the mode - FT8 has the narrowest bandwidth.
错误选项分析
Option A (MFSK16): Incorrect. MFSK16 has wider bandwidth than FT8 - FT8 is narrower. MFSK16 isn't the narrowest. Option B (170 Hz shift, 45-baud RTTY): Incorrect. 170 Hz shift RTTY has wider bandwidth than FT8 - FT8 is narrower. 170 Hz RTTY isn't the narrowest. Option D (PACTOR IV): Incorrect. PACTOR IV has wider bandwidth than FT8 - FT8 is narrower. PACTOR IV isn't the narrowest.
知识点
Digital modes, Narrowest bandwidth, FT8, Bandwidth comparison
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.