Why should an amateur operator normally avoid transmitting on 14.100, 18.110, 21.150, 24.930 and 28.200 MHz?
The correct answer is A: A system of propagation beacon stations operates on those frequencies. You should normally avoid transmitting on 14.100, 18.110, 21.150, 24.930 and 28.200 MHz because a system of propagation beacon stations operates on those frequencies. These beacons help operators assess band conditions and propagation. Transmitting on these frequencies would interfere with beacon operation. For amateur radio operators, avoiding these frequencies is good operating practice. Understanding this helps maintain clear beacon frequencies.
Exam Tip
Avoid 14.100, 18.110, 21.150, 24.930, 28.200 MHz = propagation beacons. Think 'B'eacon 'F'requencies = 'B'etter 'F'ind another frequency. Propagation beacon stations operate on these frequencies - avoid them to prevent interference. Good operating practice.
Memory Aid
"Avoid these frequencies = propagation beacons. Think 'B'eacon 'F'requencies = 'B'etter 'F'ind another. 14.100, 18.110, 21.150, 24.930, 28.200 MHz are propagation beacon frequencies. Avoid them to prevent interference."
Real-World Application
You want to call CQ on 14.100 MHz, but you hear a propagation beacon there. You should move to another frequency - 14.100 MHz is reserved for propagation beacons that help operators assess 20-meter band conditions. Transmitting on this frequency would interfere with the beacon's important function.
Key Concepts
Why Other Options Are Wrong
Option B: Incorrect. These aren't automatic digital station frequencies - they're propagation beacon frequencies. Digital stations use different frequencies.
Option C: Incorrect. These aren't emergency frequencies - they're propagation beacon frequencies. Emergency frequencies are different.
Option D: Incorrect. These aren't FCC bulletin frequencies - they're propagation beacon frequencies. FCC bulletins use different frequencies.
题目解析
The correct answer is A: A system of propagation beacon stations operates on those frequencies. You should normally avoid transmitting on 14.100, 18.110, 21.150, 24.930 and 28.200 MHz because a system of propagation beacon stations operates on those frequencies. These beacons help operators assess band conditions and propagation. Transmitting on these frequencies would interfere with beacon operation. For amateur radio operators, avoiding these frequencies is good operating practice. Understanding this helps maintain clear beacon frequencies.
考试技巧
Avoid 14.100, 18.110, 21.150, 24.930, 28.200 MHz = propagation beacons. Think 'B'eacon 'F'requencies = 'B'etter 'F'ind another frequency. Propagation beacon stations operate on these frequencies - avoid them to prevent interference. Good operating practice.
记忆口诀
Avoid these frequencies = propagation beacons. Think 'B'eacon 'F'requencies = 'B'etter 'F'ind another. 14.100, 18.110, 21.150, 24.930, 28.200 MHz are propagation beacon frequencies. Avoid them to prevent interference.
实际应用示例
You want to call CQ on 14.100 MHz, but you hear a propagation beacon there. You should move to another frequency - 14.100 MHz is reserved for propagation beacons that help operators assess 20-meter band conditions. Transmitting on this frequency would interfere with the beacon's important function.
错误选项分析
Option B: Incorrect. These aren't automatic digital station frequencies - they're propagation beacon frequencies. Digital stations use different frequencies. Option C: Incorrect. These aren't emergency frequencies - they're propagation beacon frequencies. Emergency frequencies are different. Option D: Incorrect. These aren't FCC bulletin frequencies - they're propagation beacon frequencies. FCC bulletins use different frequencies.
知识点
Propagation beacons, Beacon frequencies, Frequency avoidance, Good operating practice
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.