What type of modulation is used by FT8?
The correct answer is A: 8-tone frequency shift keying. The type of modulation used by FT8 is 8-tone frequency shift keying. FT8 uses 8 different tones (frequencies) to represent data, making it a form of FSK. For amateur radio operators, this is how FT8 works. Understanding this helps when operating FT8.
Exam Tip
FT8 modulation = 8-tone frequency shift keying. Think 'F'T8 = 'F'requency 'T'ones (8 tones) = '8'-tone 'F'SK. FT8 uses 8 different tones (frequencies) to represent data. Not vestigial sideband, not AM compression, not spread spectrum - just 8-tone FSK.
Memory Aid
"FT8 modulation = 8-tone frequency shift keying. Think 'F'T8 = '8'-tone 'F'SK. FT8 uses 8 different tones (frequencies) to represent data. Popular weak-signal digital mode."
Real-World Application
FT8 uses 8-tone frequency shift keying: The signal shifts between 8 different frequencies (tones) to represent data. Each tone represents different information. This is how FT8 encodes data - using 8-tone FSK. FT8 is a popular weak-signal digital mode that uses this modulation.
Key Concepts
Why Other Options Are Wrong
Option B (Vestigial sideband): Incorrect. FT8 doesn't use vestigial sideband - it uses FSK, not sideband modulation. VSB is for analog, not digital.
Option C (Amplitude compressed AM): Incorrect. FT8 doesn't use amplitude compressed AM - it uses FSK, not AM. AM compression isn't FT8.
Option D (8-bit direct sequence spread spectrum): Incorrect. FT8 doesn't use direct sequence spread spectrum - it uses FSK with 8 tones, not spread spectrum. Spread spectrum is different.
题目解析
The correct answer is A: 8-tone frequency shift keying. The type of modulation used by FT8 is 8-tone frequency shift keying. FT8 uses 8 different tones (frequencies) to represent data, making it a form of FSK. For amateur radio operators, this is how FT8 works. Understanding this helps when operating FT8.
考试技巧
FT8 modulation = 8-tone frequency shift keying. Think 'F'T8 = 'F'requency 'T'ones (8 tones) = '8'-tone 'F'SK. FT8 uses 8 different tones (frequencies) to represent data. Not vestigial sideband, not AM compression, not spread spectrum - just 8-tone FSK.
记忆口诀
FT8 modulation = 8-tone frequency shift keying. Think 'F'T8 = '8'-tone 'F'SK. FT8 uses 8 different tones (frequencies) to represent data. Popular weak-signal digital mode.
实际应用示例
FT8 uses 8-tone frequency shift keying: The signal shifts between 8 different frequencies (tones) to represent data. Each tone represents different information. This is how FT8 encodes data - using 8-tone FSK. FT8 is a popular weak-signal digital mode that uses this modulation.
错误选项分析
Option B (Vestigial sideband): Incorrect. FT8 doesn't use vestigial sideband - it uses FSK, not sideband modulation. VSB is for analog, not digital. Option C (Amplitude compressed AM): Incorrect. FT8 doesn't use amplitude compressed AM - it uses FSK, not AM. AM compression isn't FT8. Option D (8-bit direct sequence spread spectrum): Incorrect. FT8 doesn't use direct sequence spread spectrum - it uses FSK with 8 tones, not spread spectrum. Spread spectrum is different.
知识点
FT8, 8-tone FSK, Frequency shift keying, Digital modes
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.