*Question T8C01:
Which of the following methods is used to locate sources of noise interference or jamming?*  

*Correct Answer is  C: Radio direction finding*  

### AI Response: (may contain errors)  

To locate sources of noise interference or jamming, the correct method is:

**C: Radio direction finding**

### Explanation of the Correct Answer:
- **Radio direction finding (RDF)** is a technique used to determine the direction of a radio signal. By using multiple antennas or a rotating antenna, operators can pinpoint the source of interference or jamming. This method is effective because it allows for the identification of the signal's origin, which is crucial in addressing interference issues.

### Why the Other Choices are Incorrect:
- **A: Echolocation**
  - Echolocation is primarily used by animals (like bats) to navigate and locate objects by emitting sound waves and listening for echoes. It is not applicable to radio frequency interference.

- **B: Doppler radar**
  - Doppler radar is used to measure the velocity of objects (like weather patterns or aircraft) by analyzing the frequency shift of returned signals. While it can detect movement, it is not specifically designed for locating sources of noise interference.

- **D: Phase locking**
  - Phase locking refers to synchronizing the phase of a signal with a reference signal. This technique is used in various applications, such as in oscillators and communication systems, but it does not provide a method for locating interference sources.

### Summary:
- **Correct Method**: Radio direction finding (C) is the appropriate technique for locating noise interference.
- **Incorrect Methods**: Echolocation (A), Doppler radar (B), and phase locking (D) do not serve this purpose.

Understanding these distinctions will help you effectively answer similar questions on the Extra Class exam.