E3 Radio Wave Propagation

39 questions in the pool. Your exam will include 3, one from each group below.

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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

• E3A01What is the approximate maximum separation measured along the surface of the Earth between two stations communicating by EME?
• E3A02What characterizes libration fading of an EME signal?
• E3A03When scheduling EME contacts, which of these conditions will generally result in the least path loss?
• E3A04In what direction does an electromagnetic wave travel?
• E3A05How are the component fields of an electromagnetic wave oriented?
• E3A06What should be done to continue a long-distance contact when the MUF for that path decreases due to darkness?
• E3A07Atmospheric ducts capable of propagating microwave signals often form over what geographic feature?
• E3A08When a meteor strikes the Earth's atmosphere, a linear ionized region is formed at what region of the ionosphere?
• E3A09Which of the following frequency ranges is most suited for meteor-scatter communications?
• E3A10What determines the speed of electromagnetic waves through a medium?
• E3A11What is a typical range for tropospheric duct propagation of microwave signals?
• E3A12What is most likely to result in auroral propagation?
• E3A13Which of these emission modes is best for auroral propagation?
• E3A14What are circularly polarized electromagnetic waves?

E3B

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

• E3B01Where is transequatorial propagation (TEP) most likely to occur?
• E3B02What is the approximate maximum range for signals using transequatorial propagation?
• E3B03At what time of day is transequatorial propagation most likely to occur?
• E3B04What are “extraordinary” and “ordinary” waves?
• E3B05Which of the following paths is most likely to support long-distance propagation on 160 meters?
• E3B06On which of the following amateur bands is long-path propagation most frequent?
• E3B07What effect does lowering a signal's transmitted elevation angle have on ionospheric HF skip propagation?
• E3B08How does the maximum range of ground-wave propagation change when the signal frequency is increased?
• E3B09At what time of year is sporadic-E propagation most likely to occur?
• E3B10What is the effect of chordal-hop propagation?
• E3B11At what time of day is sporadic-E propagation most likely to occur?
• E3B12What is chordal-hop propagation?
• E3B13What type of polarization is supported by ground-wave propagation?

E3C

Propagation prediction and reporting: radio horizon; effects of space-weather phenomena

• E3C01What is the cause of short-term radio blackouts?
• E3C02What is indicated by a rising A-index or K-index?
• E3C03Which of the following signal paths is most likely to experience high levels of absorption when the A-index or K-index is elevated?
• E3C04What does the value of Bz (B sub z) represent?
• E3C05What orientation of Bz (B sub z) increases the likelihood that charged particles from the Sun will cause disturbed conditions?
• E3C06How does the VHF/UHF radio horizon compare to the geographic horizon?
• E3C07Which of the following indicates the greatest solar flare intensity?
• E3C08Which of the following is the space-weather term for an extreme geomagnetic storm?
• E3C09What type of data is reported by amateur radio propagation reporting networks?
• E3C10What does the 304A solar parameter measure?
• E3C11What does VOACAP software model?
• E3C12Which of the following is indicated by a sudden rise in radio background noise across a large portion of the HF spectrum?