General Class License Exam Questions
Radio Wave Propagation
Question Display Options:
Group G3A Sunspots and solar radiation; ionospheric disturbances; propagation forecasting and indices
G3A01 What is the significance of the sunspot number with regard to HF propagation?
G3A02 What effect does a Sudden Ionospheric Disturbance have on the daytime ionospheric propagation of HF radio waves?
G3A03 Approximately how long does it take the increased ultraviolet and X-ray radiation from solar flares to affect radio propagation on the Earth?
G3A04 Which of the following are least reliable for long distance communications during periods of low solar activity?
G3A05 What is the solar flux index?
G3A06 What is a geomagnetic storm?
G3A07 At what point in the solar cycle does the 20-meter band usually support worldwide propagation during daylight hours?
G3A08 Which of the following effects can a geomagnetic storm have on radio propagation?
G3A09 What effect does a high sunspot number have on radio communications?
G3A10 What causes HF propagation conditions to vary periodically in a 28 day cycle?
G3A11 Approximately how long is the typical sunspot cycle?
G3A12 What does the K-index indicate?
G3A13 What does the A-index indicate?
G3A14 How are radio communications usually affected by the charged particles that reach the Earth from solar coronal holes?
G3A15 How long does it take charged particles from coronal mass ejections to affect radio propagation on the Earth?
G3A16 What is a possible benefit to radio communications resulting from periods of high geomagnetic activity?
Group G3B Maximum Usable Frequency; Lowest Usable Frequency; propagation
G3B01 How might a sky-wave signal sound if it arrives at your receiver by both short path and long path propagation?
G3B02 Which of the following is a good indicator of the possibility of sky-wave propagation on the 6-meter band?
G3B03 Which of the following applies when selecting a frequency for lowest attenuation when transmitting on HF?
G3B04 What is a reliable way to determine if the MUF is high enough to support skip propagation between your station and a distant location on frequencies between 14 and 30 MHz?
G3B05 What usually happens to radio waves with frequencies below the MUF and above the LUF when they are sent into the ionosphere?
G3B06 What usually happens to radio waves with frequencies below the LUF?
G3B07 What does LUF stand for?
G3B08 What does MUF stand for?
G3B09 What is the approximate maximum distance along the Earth's surface that is normally covered in one hop using the F2 region?
G3B10 What is the approximate maximum distance along the Earth's surface that is normally covered in one hop using the E region?
G3B11 What happens to HF propagation when the LUF exceeds the MUF?
G3B12 What factor or factors affect the MUF?
Group G3C Ionospheric layers; critical angle and frequency; HF scatter; Near-Vertical Incidence Skywave
G3C01 Which ionospheric layer is closest to the surface of the Earth?
G3C02 Where on the Earth do ionospheric layers reach their maximum height?
G3C03 Why is the F2 region mainly responsible for the longest distance radio wave propagation?
G3C04 What does the term "critical angle" mean as used in radio wave propagation?
G3C05 Why is long distance communication on the 40-meter, 60-meter, 80-meter and 160-meter bands more difficult during the day?
G3C06 What is a characteristic of HF scatter signals?
G3C07 What makes HF scatter signals often sound distorted?
G3C08 Why are HF scatter signals in the skip zone usually weak?
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?
G3C10 Which of the following might be an indication that signals heard on the HF bands are being received via scatter propagation?
G3C11 Which of the following antenna types will be most effective for skip communications on 40-meters during the day?
G3C12 Which ionospheric layer is the most absorbent of long skip signals during daylight hours on frequencies below 10 MHz?
G3C13 What is Near Vertical Incidence Sky-wave (NVIS) propagation?