Deep Dive: G8A09
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.
Why Other Answers 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.
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 Example
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.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G8A
Reference: 2023-2027 Question Pool · G8 - Signals and Emissions
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G8A topic.