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| G3C01 -Which of the following ionospheric layers is closest to the surface of the Earth? A. The D layer B. The E layer C. The F1 layer D. The F2 layer |
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| G3C02 -Where on the Earth do ionospheric layers reach their maximum height? A. Where the Sun is overhead B. Where the Sun is on the opposite side of the Earth C. Where the Sun is rising D. Where the Sun has just set |
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| G3C03 -Why is the F2 region mainly responsible for the longest distance radio wave propagation? A. Because it is the densest ionospheric layer B. Because it does not absorb radio waves as much as other ionospheric regions C. Because it is the highest ionospheric region D. All of these choices are correct |
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| G3C04 -What does the term "critical angle" mean as used in radio wave propagation? A. The long path azimuth of a distant station B. The short path azimuth of a distant station C. The lowest takeoff angle that will return a radio wave to the Earth under specific ionospheric conditions D. The highest takeoff angle that will return a radio wave to the Earth under specific ionospheric conditions |
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| G3C05 -Why is long distance communication on the 40, 60, 80 and 160 meter bands more difficult during the day? A. The F layer absorbs signals at these frequencies during daylight hours B. The F layer is unstable during daylight hours C. The D layer absorbs signals at these frequencies during daylight hours D. The E layer is unstable during daylight hours |
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| G3C06 -What is a characteristic of HF scatter signals? A. They have high intelligibility B. They have a wavering sound C. They have very large swings in signal strength D. All of these choices are correct |
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| G3C07 -What makes HF scatter signals often sound distorted? A. The ionospheric layer involved is unstable B. Ground waves are absorbing much of the signal C. The E-region is not present D. Energy is scattered into the skip zone through several different radio wave paths |
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| G3C08 -Why are HF scatter signals in the skip zone usually weak? A. Only a small part of the signal energy is scattered into the skip zone B. Signals are scattered from the magnetosphere which is not a good reflector C. Propagation is through ground waves which absorb most of the signal energy D. Propagations is through ducts in F region which absorb most of the energy |
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| G3C09 -What type of radio wave propagation allows a signal to be detected at a distance too far for ground wave propagation but too near for normal sky-wave propagation? A. Faraday rotation B. Scatter C. Sporadic-E skip D. Short-path skip |
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| G3C10 -Which of the following might be an indication that signals heard on the HF bands are being received via scatter propagation? A. The communication is during a sunspot maximum B. The communication is during a sudden ionospheric disturbance C. The signal is heard on a frequency below the Maximum Usable Frequency D. The signal is heard on a frequency above the Maximum Usable Frequency |
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| G3C11 -Which of the following antenna types will be most effective for skip communications on 40 meters during the day? A. Vertical antennas B. Horizontal dipoles placed between 1/8 and 1/4 wavelength above the ground C. Left-hand circularly polarized antennas D. Right-hand circularly polarized antenna |
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| G3C12 -Which ionospheric layer is the most absorbent of long skip signals during daylight hours on frequencies below 10 MHz? A. The F2 layer B. The F1 layer C. The E layer D. The D layer |
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| G3C13 -What is Near Vertical Incidence Sky-wave (NVIS) propagation? A. Propagation near the MUF B. Short distance HF propagation using high elevation angles C. Long path HF propagation at sunrise and sunset D. Double hop propagation near the LUF |
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