*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 radio receivers designed to reduce the impact of short-duration noise pulses, such as those from ignition systems or lightning. Here's how it works:

### Correct Answer: C

- **By reducing receiver gain during a noise pulse**:  
  The noise blanker detects the presence of a noise pulse and temporarily reduces the receiver's gain. This action minimizes the effect of the noise pulse on the received signal, making it less noticeable to the listener. The reduction in gain is typically very brief, just long enough to cover the duration of the noise pulse.

### Why Other Choices Are Incorrect:

- **A: By temporarily increasing received bandwidth**:  
  Increasing the bandwidth would actually allow more noise to enter the receiver, which is the opposite of what a noise blanker aims to achieve. A noise blanker works by reducing the impact of noise, not by increasing the bandwidth.

- **B: By redirecting noise pulses into a filter capacitor**:  
  This choice suggests a method more akin to smoothing out noise in power supplies, not in radio receivers. Noise blankers do not redirect noise; they reduce the gain to minimize its effect.

- **D: By clipping noise peaks**:  
  Clipping would involve cutting off the tops of noise pulses, which can introduce distortion and affect the desired signal. Noise blankers aim to reduce the impact of noise without distorting the signal.

### Summary:

A noise blanker effectively reduces the impact of short-duration noise pulses by temporarily lowering the receiver's gain during the pulse. This method helps maintain the integrity of the desired signal while minimizing the disruptive effects of noise.