*Question T8C02:
Which of these items would be useful for a hidden transmitter hunt?*  

*Correct Answer is  B: A directional antenna*  

### AI Response: (may contain errors)  

To understand why a directional antenna is the best choice for a hidden transmitter hunt, let's break down each option:

1. **Correct Answer: A directional antenna**
   - A directional antenna focuses its reception in a specific direction, which allows you to pinpoint the location of a hidden transmitter more effectively. By rotating the antenna, you can determine the direction from which the strongest signal is coming, helping you to locate the transmitter.

2. **Why the other choices are incorrect:**
   - **A: Calibrated SWR meter**
     - An SWR (Standing Wave Ratio) meter is used to measure the efficiency of an antenna system and to ensure that the antenna is properly matched to the transmitter. While it is useful for tuning and optimizing your setup, it does not help in locating a hidden transmitter.
   
   - **C: A calibrated noise bridge**
     - A noise bridge is used to measure impedance and is primarily a tool for testing and tuning circuits. It does not provide any directional information or help in locating a signal, making it unsuitable for a hidden transmitter hunt.

   - **D: All these choices are correct**
     - Since only the directional antenna is useful for locating a hidden transmitter, this option is incorrect.

3. **Useful rules of thumb:**
   - When hunting for hidden transmitters, using a directional antenna (like a Yagi or a loop antenna) can significantly improve your chances of success. 
   - A common technique is to use the "null" method: by rotating the directional antenna, you can find the direction where the signal is weakest (the null), which indicates that you are perpendicular to the direction of the transmitter. 

In summary, for a hidden transmitter hunt, a directional antenna is essential for accurately locating the source of a signal, while the other options do not provide the necessary functionality for this task.