Podcast
Questions and Answers
What is the maximum line-of-sight (LOS) distance between two antennas with heights hT and hR above the earth?
What is the maximum line-of-sight (LOS) distance between two antennas with heights hT and hR above the earth?
- $2(RhT + RhR)$
- $2 RhT + 2 RhR$ (correct)
- $R(hT + hR)$
- $RhT + RhR$
Which type of communication uses skywave or skip propagation by reflecting or refracting radio waves back toward Earth from the ionosphere?
Which type of communication uses skywave or skip propagation by reflecting or refracting radio waves back toward Earth from the ionosphere?
- Space wave propagation
- Satellite communication
- LOS communication
- Ionospheric communication (correct)
Why are space waves suitable for very high-frequency waves and satellite communication?
Why are space waves suitable for very high-frequency waves and satellite communication?
- They follow the Earth's curvature
- They prevent loss of signal strength (correct)
- They rely on ionization
- They have high attenuation
What defines the structure of the ionosphere in terms of ionization and altitude?
What defines the structure of the ionosphere in terms of ionization and altitude?
In radio communication, what characterizes the ionospheric skip propagation?
In radio communication, what characterizes the ionospheric skip propagation?
What type of region is present in each ionized layer of the ionosphere with respect to ionization intensity?
What type of region is present in each ionized layer of the ionosphere with respect to ionization intensity?
What is the primary path of the space wave in direct wave propagation?
What is the primary path of the space wave in direct wave propagation?
At what frequencies is communication essentially limited to Line of Sight (LOS) paths?
At what frequencies is communication essentially limited to Line of Sight (LOS) paths?
What is the radio horizon of a transmitting antenna located at a height hT?
What is the radio horizon of a transmitting antenna located at a height hT?
Why must the receiving antenna be located within the radio horizon of the transmitting antenna in direct wave propagation?
Why must the receiving antenna be located within the radio horizon of the transmitting antenna in direct wave propagation?
What happens to direct waves at frequencies above 40 MHz if the antennas are relatively smaller and placed at great heights above the ground?
What happens to direct waves at frequencies above 40 MHz if the antennas are relatively smaller and placed at great heights above the ground?
In direct wave propagation, why does the receiving antenna need to be high enough to intercept Line of Sight (LOS) waves if the signal is to be received beyond the horizon?
In direct wave propagation, why does the receiving antenna need to be high enough to intercept Line of Sight (LOS) waves if the signal is to be received beyond the horizon?
What is the primary mode of propagation used for distances greater than 1000 km?
What is the primary mode of propagation used for distances greater than 1000 km?
During daytime broadcast in the MF range (300 KHz - 3000 KHz), what type of propagation is relied upon?
During daytime broadcast in the MF range (300 KHz - 3000 KHz), what type of propagation is relied upon?
At what frequencies do VHF waves operate?
At what frequencies do VHF waves operate?
Why is communication beyond line-of-sight distance not appreciably possible in the HF range?
Why is communication beyond line-of-sight distance not appreciably possible in the HF range?
Which range of frequencies can propagate as ground waves over short distances with negligible diffraction?
Which range of frequencies can propagate as ground waves over short distances with negligible diffraction?
What factor determines the distance that UHF and SHF waves can travel?
What factor determines the distance that UHF and SHF waves can travel?
