Deep Dive: G4A07
The correct answer is A: Received signals may become distorted. What happens as a receiver's noise reduction control level is increased is that received signals may become distorted. Noise reduction processes the signal to reduce noise, but excessive noise reduction can distort the signal. For amateur radio operators, this is a trade-off - more noise reduction may mean more distortion. Understanding this helps when using noise reduction.
Why Other Answers Are Wrong
Option B: Incorrect. Noise reduction doesn't make frequency unstable - it processes the signal, not the frequency. Frequency stability isn't affected. Option C: Incorrect. Noise reduction doesn't severely attenuate CW signals - it may affect them, but severe attenuation isn't typical. Distortion is the main issue. Option D: Incorrect. Noise reduction doesn't shift frequency - it processes the signal, not the frequency. Frequency shift isn't an effect.
Exam Tip
Increased noise reduction = received signals may become distorted. Think 'N'oise 'R'eduction = 'N'oise 'R'educed but 'R'isk of distortion. Excessive noise reduction can distort signals. Not frequency instability, not CW attenuation, not frequency shift - just distortion.
Memory Aid
Increased noise reduction = received signals may become distorted. Think 'N'oise 'R'eduction = 'N'oise 'R'educed but 'R'isk. Excessive noise reduction can distort signals. Trade-off between noise reduction and signal quality.
Real-World Example
You increase the noise reduction control to reduce background noise. At moderate levels, noise is reduced with minimal distortion. At high levels, the signal may become distorted as the noise reduction algorithm processes the signal too aggressively. There's a trade-off between noise reduction and signal quality.
Source & Coverage
Question Pool: 2023-2027 Question Pool
Subelement: G4A
Reference: 2023-2027 Question Pool · G4 - Amateur Radio Practices
Key Concepts
Verified Content
Question from the official FCC General Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the G4A topic.