On what HF frequencies are automatically controlled beacons permitted?
The correct answer is D: 28.20 MHz to 28.30 MHz. Automatically controlled beacons are permitted on HF frequencies 28.20 MHz to 28.30 MHz (10-meter band). This is the designated beacon segment on 10 meters for automatically controlled beacons. For amateur radio operators, understanding beacon frequency allocations helps when operating or monitoring beacons. This 100 kHz segment is reserved for beacon operation on 10 meters.
Exam Tip
HF automatically controlled beacons = 28.20-28.30 MHz (10 meters). Think '1'0m 'B'eacons = '2'8.20-28.30 MHz. Designated 100 kHz segment on 10 meters for automatically controlled beacons. Not about power or mode - specific frequency range.
Memory Aid
"HF automatically controlled beacons = 28.20-28.30 MHz. Think '1'0m 'B'eacons = '2'8.20-28.30 MHz. Designated segment on 10 meters for automatically controlled beacons. 100 kHz allocation."
Real-World Application
You want to operate an automatically controlled beacon on HF. The designated frequency range is 28.20-28.30 MHz on 10 meters. This 100 kHz segment is reserved for beacon operation. You cannot operate an automatically controlled beacon on other HF frequencies - they must use this specific range.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Beacons aren't permitted on any frequency if power is less than 1 watt - power level doesn't determine where beacons can operate. They must use designated frequencies.
Option B: Incorrect. Beacons aren't permitted on any frequency if transmissions are in Morse code - mode doesn't determine frequency. Beacons must use designated frequencies.
Option C: Incorrect. 21.08-21.09 MHz is on 15 meters, not a designated beacon frequency. 10 meters has the HF beacon allocation.
题目解析
The correct answer is D: 28.20 MHz to 28.30 MHz. Automatically controlled beacons are permitted on HF frequencies 28.20 MHz to 28.30 MHz (10-meter band). This is the designated beacon segment on 10 meters for automatically controlled beacons. For amateur radio operators, understanding beacon frequency allocations helps when operating or monitoring beacons. This 100 kHz segment is reserved for beacon operation on 10 meters.
考试技巧
HF automatically controlled beacons = 28.20-28.30 MHz (10 meters). Think '1'0m 'B'eacons = '2'8.20-28.30 MHz. Designated 100 kHz segment on 10 meters for automatically controlled beacons. Not about power or mode - specific frequency range.
记忆口诀
HF automatically controlled beacons = 28.20-28.30 MHz. Think '1'0m 'B'eacons = '2'8.20-28.30 MHz. Designated segment on 10 meters for automatically controlled beacons. 100 kHz allocation.
实际应用示例
You want to operate an automatically controlled beacon on HF. The designated frequency range is 28.20-28.30 MHz on 10 meters. This 100 kHz segment is reserved for beacon operation. You cannot operate an automatically controlled beacon on other HF frequencies - they must use this specific range.
错误选项分析
Option A: Incorrect. Beacons aren't permitted on any frequency if power is less than 1 watt - power level doesn't determine where beacons can operate. They must use designated frequencies. Option B: Incorrect. Beacons aren't permitted on any frequency if transmissions are in Morse code - mode doesn't determine frequency. Beacons must use designated frequencies. Option C: Incorrect. 21.08-21.09 MHz is on 15 meters, not a designated beacon frequency. 10 meters has the HF beacon allocation.
知识点
Automatically controlled beacons, 10-meter beacons, Beacon frequencies, HF beacons
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.