What is a symptom of RF feedback in a transmitter or transceiver?
The correct answer is C: Reports of garbled, distorted, or unintelligible voice transmissions. A symptom of RF feedback in a transmitter or transceiver is garbled, distorted, or unintelligible voice transmissions. RF feedback occurs when RF energy from the transmitter couples back into the microphone, audio circuits, or control circuits, causing the audio to be modulated by the RF signal. This creates distortion, feedback, and unintelligible audio. For amateur radio operators, RF feedback is a common problem that can be solved with ferrite chokes on cables, proper grounding, and good station layout. Understanding this symptom helps identify and fix RF feedback problems quickly.
Exam Tip
RF feedback = garbled/distorted audio. Think 'R'F 'F'eedback = 'R'eports of 'F'aulty audio. RF coupling into audio circuits causes distortion. SWR, frequency, and fuses are different problems.
Memory Aid
"RF feedback = Reports of Faulty audio. Think 'R'F 'F'eedback = 'R'eports of 'F'aulty (garbled/distorted) audio. RF coupling causes audio distortion."
Real-World Application
When you transmit, people report your audio is garbled and distorted, making you hard to understand. This is RF feedback - RF from your antenna is coupling into your microphone cable or audio circuits, modulating your voice with the RF signal. Installing ferrite chokes on your microphone cable and ensuring proper grounding usually fixes the problem.
Key Concepts
Why Other Options Are Wrong
Option A: Incorrect. Excessive SWR indicates an antenna mismatch, not RF feedback. While high SWR can cause problems, it's not the symptom of RF feedback.
Option B: Incorrect. Frequency instability is caused by oscillator problems or temperature changes, not RF feedback. RF feedback affects audio, not frequency stability.
Option D: Incorrect. Blowing fuses indicates overcurrent problems, not RF feedback. RF feedback doesn't cause excessive current draw.
题目解析
The correct answer is C: Reports of garbled, distorted, or unintelligible voice transmissions. A symptom of RF feedback in a transmitter or transceiver is garbled, distorted, or unintelligible voice transmissions. RF feedback occurs when RF energy from the transmitter couples back into the microphone, audio circuits, or control circuits, causing the audio to be modulated by the RF signal. This creates distortion, feedback, and unintelligible audio. For amateur radio operators, RF feedback is a common problem that can be solved with ferrite chokes on cables, proper grounding, and good station layout. Understanding this symptom helps identify and fix RF feedback problems quickly.
考试技巧
RF feedback = garbled/distorted audio. Think 'R'F 'F'eedback = 'R'eports of 'F'aulty audio. RF coupling into audio circuits causes distortion. SWR, frequency, and fuses are different problems.
记忆口诀
RF feedback = Reports of Faulty audio. Think 'R'F 'F'eedback = 'R'eports of 'F'aulty (garbled/distorted) audio. RF coupling causes audio distortion.
实际应用示例
When you transmit, people report your audio is garbled and distorted, making you hard to understand. This is RF feedback - RF from your antenna is coupling into your microphone cable or audio circuits, modulating your voice with the RF signal. Installing ferrite chokes on your microphone cable and ensuring proper grounding usually fixes the problem.
错误选项分析
Option A: Incorrect. Excessive SWR indicates an antenna mismatch, not RF feedback. While high SWR can cause problems, it's not the symptom of RF feedback. Option B: Incorrect. Frequency instability is caused by oscillator problems or temperature changes, not RF feedback. RF feedback affects audio, not frequency stability. Option D: Incorrect. Blowing fuses indicates overcurrent problems, not RF feedback. RF feedback doesn't cause excessive current draw.
知识点
RF feedback, Audio distortion, RF coupling, Transmitter problems
Verified Content
Question from official FCC Technician Class question pool. Explanation reviewed by licensed amateur radio operators.