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Learn / Amateur Extra course

Lesson 3: Radio Wave Propagation

Lesson 3 of 10, syllabus topic E3. The exam asks 3 questions from this topic, one from each of its 3 groups.

Propagation at this level adds the specialized modes: Earth-Moon-Earth, meteor scatter, transequatorial and long path.

What you will learn

  • E3A Electromagnetic Waves and Specialized Propagation: Earth-Moon-Earth (EME) communications; meteor scatter; microwave tropospheric and scatter propagation; auroral propagation; daily variation of ionospheric propagation; circular polarization
  • E3B Transequatorial propagation; long-path propagation; ordinary and extraordinary waves; chordal hop; sporadic-E mechanisms; ground-wave propagation
  • E3C Propagation prediction and reporting: radio horizon; effects of space-weather phenomena

1. Read

  1. How radio signals travel: VHF and UHF beyond the horizonHelps with E3A, E3B
  2. How radio signals travel: Ground waveHelps with E3B
  3. How radio signals travel: Line of sight and the radio horizonHelps with E3C
  4. How radio signals travel: When the Sun misbehavesHelps with E3C
  5. How radio signals travel: Checking conditions right nowHelps with E3C
  6. All 39 E3 questions with their answers and explanationsEvery group, with the rule or source behind each answer

2. Explore

  • Propagation conditions

    Move the time across a full day and watch the boundary between day and night sweep around the map.

  • Grid square locator

    Find the long path heading to a distant station: 180 degrees from the short path. Long path is most frequent on 40 and 20 meters.

    This is exam question E3B06.

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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