Deep Dive: E4E09
The correct answer is C: Strong signals may be distorted and appear to cause spurious emissions. What undesirable effect can occur when using a noise blanker is that strong signals may be distorted and appear to cause spurious emissions. Noise blankers can distort strong signals. For amateur radio operators, this is important for receiver operation. Understanding this helps when using noise blankers.
Why Other Answers Are Wrong
Option A: Incorrect. Received audio having echo effect isn't the problem - strong signals being distorted is the problem. Echo effect isn't the problem. Option B: Incorrect. Audio frequency bandwidth compression isn't the problem - strong signals being distorted is the problem. Bandwidth compression isn't the problem. Option D: Incorrect. FM signals no longer being demodulated isn't the problem - strong signals being distorted is the problem. FM demodulation isn't the problem.
Exam Tip
Noise blanker undesirable effect = strong signals may be distorted and appear to cause spurious emissions. Think 'N'oise 'B'lanker = 'N'egative 'B'yeffect on strong signals. Noise blankers can distort strong signals. Not echo, not bandwidth compression, not FM demodulation - just strong signal distortion.
Memory Aid
Noise blanker undesirable effect = strong signals may be distorted and appear to cause spurious emissions. Think 'N'oise 'B'lanker = 'S'trong signal distortion. Noise blankers can distort strong signals. Important for receiver operation.
Real-World Example
Using a noise blanker: An undesirable effect is that strong signals may be distorted and appear to cause spurious emissions. The noise blanker can clip or distort strong signals, making them look like spurious emissions. This is the effect - strong signal distortion.
Source & Coverage
Question Pool: 2024-2028 Question Pool
Subelement: E4E
Reference: 2024-2028 Question Pool · E4 - Amateur Practices
Key Concepts
Verified Content
Question from the official FCC Extra Class pool. Explanation reviewed by licensed amateur radio operators and mapped to the E4E topic.