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E3B01

RADIO WAVE PROPAGATION · Transequatorial propagation; long-path propagation; ordinary and extraordinary waves; chordal hop; sporadic-E mechanisms; ground-wave propagation

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Where is transequatorial propagation (TEP) most likely to occur?

  1. ABetween points separated by 2,000 miles to 3,000 miles over a path perpendicular to the geomagnetic equator
  2. BBetween points located 1,500 miles to 2,000 miles apart on the geomagnetic equator
  3. CBetween points located at each other's antipode
  4. DThrough the region where the terminator crosses the geographic equator
Why Transequatorial propagation depends on the ionization crests that form on either side of the geomagnetic equator, so it links stations that are roughly equidistant north and south of it. That means the path runs north-south, perpendicular to the magnetic equator, and typical distances are about 2,000 to 3,000 miles total. The signal effectively takes a high chordal hop between the two ionization crests, often supporting VHF contacts well above the normal MUF.
Watch out Stations sitting on the geomagnetic equator itself are not in the right geometry; the enhanced ionization crests lie a bit north and south of it, and the choice with antipodal points describes long-path propagation instead.
TEP = Trans (across) the Equator: north-south path crossing the magnetic equator, about 2,000 to 3,000 miles.
HamSandwich explanation, first draft. The question and answers are the NCVEC text.
All of E3B E3B02 →

The rest of E3B

  1. E3B01 Where is transequatorial propagation (TEP) most likely to occur?
  2. E3B02 What is the approximate maximum range for signals using transequatorial propagation?
  3. E3B03 At what time of day is transequatorial propagation most likely to occur?
  4. E3B04 What are "extraordinary" and "ordinary" waves?
  5. E3B05 Which of the following paths is most likely to support long-distance propagation on 160 meters?
  6. E3B06 On which of the following amateur bands is long-path propagation most frequent?
  7. E3B07 What effect does lowering a signal's transmitted elevation angle have on ionospheric HF skip propagation?
  8. E3B08 How does the maximum range of ground-wave propagation change when the signal frequency is increased?
  9. E3B09 At what time of year is sporadic-E propagation most likely to occur?
  10. E3B10 What is the effect of chordal-hop propagation?
  11. E3B11 At what time of day is sporadic-E propagation most likely to occur?
  12. E3B12 What is chordal-hop propagation?
  13. E3B13 What type of polarization is supported by ground-wave propagation?
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