FCCライセンス General 7月 8 2024 SUBELEMENT G3B SUBELEMENT G3B G3B – Maximum Usable Frequency; Lowest Usable Frequency; short path and long path propagation; determining propagation conditions; ionospheric refraction 1 / 12 G3B01What is a characteristic of skywave signals arriving at your location by both short-path and long-path propagation? A. Periodic fading approximately every 10 seconds B. Signal strength increased by 3 dB C. The signal might be cancelled causing severe attenuation D. A slightly delayed echo might be heard 2 / 12 G3B02What factors affect the MUF? A. Path distance and location B. Time of day and season C. Solar radiation and ionospheric disturbances D. All these choices are correct 3 / 12 G3B03Which frequency will have the least attenuation for long-distance skip propagation? A. Just below the MUF B. Just above the LUF C. Just below the critical frequency D. Just above the critical frequency 4 / 12 G3B04Which of the following is a way to determine current propagation on a desired band from your station?Use a network of automated receiving stations on the internet to see where your transmissions are being received A. Use a network of automated receiving stations on the internet to see where your transmissions are being received B. Check the A-index C. Send a series of dots and listen for echoes D. All these choices are correct 5 / 12 G3B05How does the ionosphere affect radio waves with frequencies below the MUF and above the LUF? A. They are refracted back to Earth B. They pass through the ionosphere C. They are amplified by interaction with the ionosphere D. They are refracted and trapped in the ionosphere to circle Earth 6 / 12 G3B06What usually happens to radio waves with frequencies below the LUF? A. They are refracted back to Earth B. They pass through the ionosphere C. They are attenuated before reaching the destination D. They are refracted and trapped in the ionosphere to circle Earth 7 / 12 G3B07What does LUF stand for? A. The Lowest Usable Frequency for communications between two specific points B. Lowest Usable Frequency for communications to any point outside a 100-mile radius C. The Lowest Usable Frequency during a 24-hour period D. Lowest Usable Frequency during the past 60 minutes 8 / 12 G3B08What does MUF stand for? A. The Minimum Usable Frequency for communications between two points B. The Maximum Usable Frequency for communications between two points C. The Minimum Usable Frequency during a 24-hour period D. The Maximum Usable Frequency during a 24-hour period 9 / 12 G3B09What is the approximate maximum distance along the Earth’s surface normally covered in one hop using the F2 region? A. 180 miles B. 1,200 miles C. 2,500 miles D. 12,000 miles 10 / 12 G3B10What is the approximate maximum distance along the Earth’s surface normally covered in one hop using the E region? A. 180 miles B. 1,200 miles C. 2,500 miles D. 12,000 miles 11 / 12 G3B11What happens to HF propagation when the LUF exceeds the MUF? A. Propagation via ordinary skywave communications is not possible over that path B. HF communications over the path are enhanced C. Double-hop propagation along the path is more common D. Propagation over the path on all HF frequencies is enhanced 12 / 12 G3B12Which of the following is typical of the lower HF frequencies during the summer? A. Poor propagation at any time of day B. World-wide propagation during daylight hours C. Heavy distortion on signals due to photon absorption D. High levels of atmospheric noise or static あなたのスコアは平均スコアは 41% 0% クイズを再開する Ed 0 コメント
