2016-E3B: Transequatorial propagation; long path; gray-line; multi-path; ordinary and extraordinary waves; chordal hop, sporadic E mechanisms
What is transequatorial propagation?
Propagation between two mid-latitude points at approximately the same distance north and south of the magnetic equator
Propagation between any two points located on the magnetic equator
Propagation between two continents by way of ducts along the magnetic equator
Propagation between two stations at the same latitude
What is the approximate maximum range for signals using transequatorial propagation?
What is the best time of day for transequatorial propagation?
Afternoon or early evening
Late at night
What is meant by the terms extraordinary and ordinary waves?
Independent waves created in the ionosphere that are elliptically polarized
Extraordinary waves describe rare long skip propagation compared to ordinary waves which travel shorter distances
Long path and short path waves
Refracted rays and reflected waves
Which amateur bands typically support long-path propagation?
160 meters to 10 meters
160 meters to 40 meters
30 meters to 10 meters
6 meters to 2 meters
Which of the following amateur bands most frequently provides long-path propagation?
Which of the following could account for hearing an echo on the received signal of a distant station?
Receipt of a signal by more than one path
High D layer absorption
Transmit frequency is higher than the MUF
What type of HF propagation is probably occurring if radio signals travel along the terminator between daylight and darkness?
At what time of year is Sporadic E propagation most likely to occur?
Around the solstices, especially the summer solstice
Around the solstices, especially the winter solstice
Around the equinoxes, especially the spring equinox
Around the equinoxes, especially the fall equinox
What is the cause of gray-line propagation?
At twilight and sunrise, D-layer absorption is low while E-layer and F-layer propagation remains high
At midday, the Sun super heats the ionosphere causing increased refraction of radio waves
In darkness, solar absorption drops greatly while atmospheric ionization remains steady
At mid-afternoon, the Sun heats the ionosphere decreasing radio wave refraction and the MUF
At what time of day is Sporadic-E propagation most likely to occur?
What is the primary characteristic of chordal hop propagation?
Successive ionospheric reflections without an intermediate reflection from the ground
Propagation away from the great circle bearing between stations
Propagation across the geomagnetic equator
Signals reflected back toward the transmitting station
Why is chordal hop propagation desirable?
The signal experiences less loss along the path compared to normal skip propagation
The MUF for chordal hop propagation is much lower than for normal skip propagation
Atmospheric noise is lower in the direction of chordal hop propagation
Signals travel faster along ionospheric chords
What happens to linearly polarized radio waves that split into ordinary and extraordinary waves in the ionosphere?
They become elliptically polarized
They are bent toward the magnetic poles
Their polarization is randomly modified
They become phase-locked
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● = Incorrect answer