*Question G4A03:
How does a noise blanker work?*  

*Correct Answer is  C: By reducing receiver gain during a noise pulse*  

### AI Response: (may contain errors)  

A noise blanker is a feature in some receivers that helps to reduce the impact of short-duration noise pulses, such as those caused by ignition systems in vehicles or other electrical devices. 

### Correct Answer: C - By reducing receiver gain during a noise pulse

- **Explanation**: The noise blanker works by detecting the presence of a noise pulse and temporarily reducing the gain of the receiver during that pulse. This helps to prevent the noise from being amplified and interfering with the desired signal. By lowering the gain, the receiver can effectively "ignore" the noise, allowing for clearer reception of the intended signals.

### Why the Other Choices are Incorrect:

- **A: By temporarily increasing received bandwidth**  
  - Increasing the bandwidth would allow more noise to enter the receiver, which is counterproductive. Noise blankers aim to filter out noise, not to increase the amount of noise received.

- **B: By redirecting noise pulses into a filter capacitor**  
  - This option suggests a method of filtering that is not how noise blankers operate. Noise blankers do not redirect noise pulses; instead, they reduce the gain to minimize the effect of the noise.

- **D: By clipping noise peaks**  
  - Clipping noise peaks would imply that the receiver is cutting off parts of the signal, which could distort the desired signal as well. Noise blankers do not clip; they reduce gain to avoid amplifying the noise.

### Summary

- A noise blanker reduces receiver gain during noise pulses to improve signal clarity.
- It does not increase bandwidth, redirect noise, or clip signals.

Understanding how noise blankers function is crucial for effective operation in noisy environments, making this knowledge valuable for your Extra Class exam preparation.