What is FT8?
The correct answer is B: A digital mode capable of low signal-to-noise operation. FT8 is a digital mode capable of low signal-to-noise operation. FT8 is part of the WSJT-X software suite and is designed for weak-signal work, allowing contacts when signals are too weak for other modes. FT8 uses very narrow bandwidth (about 50 Hz), transmits for 13 seconds, and can decode signals that are many dB below the noise floor. For amateur radio operators, FT8 has revolutionized weak-signal work, making contacts possible that were previously impossible. Understanding FT8 helps explain modern weak-signal digital operation.
Exam Tip
FT8 = weak-signal digital mode. Think 'F'T8 = 'F'aint 'T'ext mode (8 seconds). Narrow bandwidth (~50 Hz), low signal-to-noise capability, excellent for weak-signal contacts. Not FM voice, not multiplex, not TV.
Memory Aid
"FT8 = weak-signal digital mode. Think 'F'T8 = 'F'aint 'T'ext mode. Capable of low signal-to-noise operation, narrow bandwidth (~50 Hz), excellent for weak-signal work. Part of WSJT-X suite."
Real-World Application
You operate FT8 on 20 meters during poor band conditions. FT8 can decode signals that are completely inaudible and buried in noise - signals that SSB or CW couldn't copy. The mode transmits for 13 seconds, then listens for 13 seconds, automatically making contacts with stations you can barely see on the waterfall display. FT8 has made weak-signal contacts routine.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. FT8 is not a wideband FM voice mode - it's a narrowband digital mode (about 50 Hz bandwidth). FM voice uses about 15 kHz.
Option C: Incorrect. FT8 is not an 8-channel multiplex mode for FM repeaters - it's a single-channel digital mode for weak-signal work, not for repeaters.
Option D: Incorrect. FT8 is not a slow-scan TV mode - it's a text-based digital mode for making contacts, not for video transmission.
题目解析
The correct answer is B: A digital mode capable of low signal-to-noise operation. FT8 is a digital mode capable of low signal-to-noise operation. FT8 is part of the WSJT-X software suite and is designed for weak-signal work, allowing contacts when signals are too weak for other modes. FT8 uses very narrow bandwidth (about 50 Hz), transmits for 13 seconds, and can decode signals that are many dB below the noise floor. For amateur radio operators, FT8 has revolutionized weak-signal work, making contacts possible that were previously impossible. Understanding FT8 helps explain modern weak-signal digital operation.
考试技巧
FT8 = weak-signal digital mode. Think 'F'T8 = 'F'aint 'T'ext mode (8 seconds). Narrow bandwidth (~50 Hz), low signal-to-noise capability, excellent for weak-signal contacts. Not FM voice, not multiplex, not TV.
记忆口诀
FT8 = weak-signal digital mode. Think 'F'T8 = 'F'aint 'T'ext mode. Capable of low signal-to-noise operation, narrow bandwidth (~50 Hz), excellent for weak-signal work. Part of WSJT-X suite.
实际应用示例
You operate FT8 on 20 meters during poor band conditions. FT8 can decode signals that are completely inaudible and buried in noise - signals that SSB or CW couldn't copy. The mode transmits for 13 seconds, then listens for 13 seconds, automatically making contacts with stations you can barely see on the waterfall display. FT8 has made weak-signal contacts routine.
错误选项分析
Option A: Incorrect. FT8 is not a wideband FM voice mode - it's a narrowband digital mode (about 50 Hz bandwidth). FM voice uses about 15 kHz. Option C: Incorrect. FT8 is not an 8-channel multiplex mode for FM repeaters - it's a single-channel digital mode for weak-signal work, not for repeaters. Option D: Incorrect. FT8 is not a slow-scan TV mode - it's a text-based digital mode for making contacts, not for video transmission.
知识点
FT8, Weak signal digital mode, Low signal-to-noise, WSJT-X
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.