Deep Dive: E4E03
The correct answer is B: Impulse noise. Which of the following types of noise are removed by a noise blanker is impulse noise. Noise blankers are designed to remove impulse noise (short bursts). For amateur radio operators, this is important for receiver operation. Understanding this helps when using noise blankers.
Why Other Answers Are Wrong
Option A (Broadband white noise): Incorrect. Broadband white noise isn't removed by noise blankers - noise blankers remove impulse noise. Broadband white noise isn't removed. Option C (Hum and buzz): Incorrect. Hum and buzz aren't removed by noise blankers - noise blankers remove impulse noise. Hum and buzz aren't removed. Option D: Incorrect. Since A and C are not correct, 'all of the above' cannot be correct. Only impulse noise is removed.
Exam Tip
Noise blanker removes = impulse noise. Think 'N'oise 'B'lanker = 'N'arrow 'B'ursts (impulse). Noise blankers are designed to remove impulse noise (short bursts). Not broadband white noise, not hum and buzz - just impulse noise.
Memory Aid
Noise blanker removes = impulse noise. Think 'N'oise 'B'lanker = 'I'mpulse noise. Noise blankers are designed to remove impulse noise (short bursts). Important for receiver operation.
Real-World Example
A noise blanker: It removes impulse noise - short bursts of noise like ignition noise, power line arcing, etc. Noise blankers detect these impulses and blank (mute) the receiver during the impulse. This is what noise blankers remove - impulse noise.
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.