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Learn / Amateur Extra course

Lesson 7: Signals and Emissions

Lesson 7 of 10, syllabus topic E8. The exam asks 4 questions from this topic, one from each of its 4 groups.

Signals and emissions cover Fourier analysis, peak and average power, modulation and digital signal design.

What you will learn

  • E8A Fourier analysis; RMS measurements; average RF power and peak envelope power (PEP); analog/digital conversion
  • E8B Modulation and demodulation: modulation methods; modulation index and deviation ratio; frequency- and time-division multiplexing; orthogonal frequency-division multiplexing (OFDM)
  • E8C Digital signals: digital communication modes; information rate vs. bandwidth; error correction; constellation diagrams
  • E8D Keying defects and overmodulation of digital signals; digital codes; spread spectrum

1. Read

  1. Digital modes: FT8 and FT4Helps with E8C
  2. Digital modes: PSK31 and RTTYHelps with E8C, E8D
  3. All 48 E8 questions with their answers and explanationsEvery group, with the rule or source behind each answer

2. Explore

No interactive tool covers this topic yet. Go on to practice.

3. Practice

Practice one group at a time. A group is ready when you have answered every one of its questions and learned at least 80 percent of them; a question counts as learned when your last three answers to it were correct. To review quickly, go through this lesson’s questions as flashcards.

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