How are the two separate frequencies of a Frequency Shift Keyed (FSK) signal identified?
The correct answer is D: Mark and space. The two separate frequencies of a Frequency Shift Keyed (FSK) signal are identified as mark and space. Mark and space are the traditional terms for the two FSK frequencies (mark = one frequency, space = the other). For amateur radio operators, this is standard FSK terminology. Understanding this helps when operating FSK modes.
Exam Tip
FSK two frequencies = mark and space. Think 'F'SK = 'F'requency 'S'hift 'K'eying = 'M'ark and 'S'pace. Mark and space are the traditional terms for the two FSK frequencies. Not dot/dash (CW), not on/off, not high/low - just mark and space.
Memory Aid
"FSK two frequencies = mark and space. Think 'F'SK = 'M'ark and 'S'pace. Mark and space are the traditional terms for the two FSK frequencies. Standard FSK terminology."
Real-World Application
An FSK signal: One frequency represents 'mark' (logical 1), another frequency represents 'space' (logical 0). The signal shifts between these two frequencies to encode data. Mark and space are the standard terms for FSK frequencies - this is how FSK signals are identified.
Key Concepts
Why Other Options Are Wrong
Option A (Dot and dash): Incorrect. Dot and dash are for CW (Morse code), not FSK - FSK uses mark and space frequencies. Dot/dash are different.
Option B (On and off): Incorrect. On and off are too general - FSK uses specific frequency terms (mark and space). On/off aren't the FSK terms.
Option C (High and low): Incorrect. High and low are too generic - FSK uses mark and space, not high/low. High/low aren't the standard FSK terms.
题目解析
The correct answer is D: Mark and space. The two separate frequencies of a Frequency Shift Keyed (FSK) signal are identified as mark and space. Mark and space are the traditional terms for the two FSK frequencies (mark = one frequency, space = the other). For amateur radio operators, this is standard FSK terminology. Understanding this helps when operating FSK modes.
考试技巧
FSK two frequencies = mark and space. Think 'F'SK = 'F'requency 'S'hift 'K'eying = 'M'ark and 'S'pace. Mark and space are the traditional terms for the two FSK frequencies. Not dot/dash (CW), not on/off, not high/low - just mark and space.
记忆口诀
FSK two frequencies = mark and space. Think 'F'SK = 'M'ark and 'S'pace. Mark and space are the traditional terms for the two FSK frequencies. Standard FSK terminology.
实际应用示例
An FSK signal: One frequency represents 'mark' (logical 1), another frequency represents 'space' (logical 0). The signal shifts between these two frequencies to encode data. Mark and space are the standard terms for FSK frequencies - this is how FSK signals are identified.
错误选项分析
Option A (Dot and dash): Incorrect. Dot and dash are for CW (Morse code), not FSK - FSK uses mark and space frequencies. Dot/dash are different. Option B (On and off): Incorrect. On and off are too general - FSK uses specific frequency terms (mark and space). On/off aren't the FSK terms. Option C (High and low): Incorrect. High and low are too generic - FSK uses mark and space, not high/low. High/low aren't the standard FSK terms.
知识点
FSK, Mark and space, Two frequencies, Frequency shift keying
Verified Content
Question from official FCC General Class question pool. Explanation reviewed by licensed amateur radio operators.