Which of the following methods measures intermodulation distortion in an SSB transmitter?
The correct answer is B: Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer. Which of the following methods measures intermodulation distortion in an SSB transmitter is to modulate with two AF signals having non-harmonically related frequencies and observe RF output with spectrum analyzer. Two-tone test measures IMD. For amateur radio operators, this is important for transmitter testing. Understanding this helps when testing transmitters.
Exam Tip
Measure IMD in SSB transmitter = modulate with two AF signals (non-harmonically related), observe RF output with spectrum analyzer. Think 'I'MD = 'T'wo-'T'one 'T'est. Two-tone test measures IMD. Not RF signals, not harmonically related, not logic analyzer - just two AF signals and spectrum analyzer.
Memory Aid
"Measure IMD in SSB transmitter = modulate with two AF signals (non-harmonically related), observe RF output with spectrum analyzer. Think 'I'MD = 'T'wo-'T'one test. Two-tone test measures IMD. Important for transmitter testing."
Real-World Application
Measuring intermodulation distortion in an SSB transmitter: Modulate the transmitter using two AF (audio) signals having non-harmonically related frequencies (e.g., 1 kHz and 2.5 kHz), and observe the RF output with a spectrum analyzer. The spectrum analyzer will show IMD products. This is the method - two AF tones and spectrum analyzer.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Two RF signals isn't correct - two AF (audio) signals are used for IMD testing. RF signals isn't the method.
Option C: Incorrect. Harmonically related frequencies isn't correct - non-harmonically related frequencies are needed. Harmonically related isn't correct.
Option D: Incorrect. Logic analyzer isn't used - spectrum analyzer is used to observe IMD products. Logic analyzer isn't used.
题目解析
The correct answer is B: Modulate the transmitter using two AF signals having non-harmonically related frequencies and observe the RF output with a spectrum analyzer. Which of the following methods measures intermodulation distortion in an SSB transmitter is to modulate with two AF signals having non-harmonically related frequencies and observe RF output with spectrum analyzer. Two-tone test measures IMD. For amateur radio operators, this is important for transmitter testing. Understanding this helps when testing transmitters.
考试技巧
Measure IMD in SSB transmitter = modulate with two AF signals (non-harmonically related), observe RF output with spectrum analyzer. Think 'I'MD = 'T'wo-'T'one 'T'est. Two-tone test measures IMD. Not RF signals, not harmonically related, not logic analyzer - just two AF signals and spectrum analyzer.
记忆口诀
Measure IMD in SSB transmitter = modulate with two AF signals (non-harmonically related), observe RF output with spectrum analyzer. Think 'I'MD = 'T'wo-'T'one test. Two-tone test measures IMD. Important for transmitter testing.
实际应用示例
Measuring intermodulation distortion in an SSB transmitter: Modulate the transmitter using two AF (audio) signals having non-harmonically related frequencies (e.g., 1 kHz and 2.5 kHz), and observe the RF output with a spectrum analyzer. The spectrum analyzer will show IMD products. This is the method - two AF tones and spectrum analyzer.
错误选项分析
Option A: Incorrect. Two RF signals isn't correct - two AF (audio) signals are used for IMD testing. RF signals isn't the method. Option C: Incorrect. Harmonically related frequencies isn't correct - non-harmonically related frequencies are needed. Harmonically related isn't correct. Option D: Incorrect. Logic analyzer isn't used - spectrum analyzer is used to observe IMD products. Logic analyzer isn't used.
知识点
Intermodulation distortion, SSB transmitter, Two AF signals, Non-harmonically related frequencies, Spectrum analyzer
Verified Content
Question from official FCC Extra Class question pool. Explanation reviewed by licensed amateur radio operators.