*Question G0A09:
What type of instrument can be used to accurately measure an RF field strength?*  

*Correct Answer is  B: A calibrated field strength meter with a calibrated antenna*  

### AI Response: (may contain errors)  

To accurately measure an RF field strength, you need a device specifically designed for that purpose. Here's why the correct answer is a calibrated field strength meter with a calibrated antenna:

1. **Correct Answer: B - A calibrated field strength meter with a calibrated antenna**
   - A field strength meter is specifically designed to measure the strength of radio frequency (RF) fields. When it is calibrated, it provides accurate and reliable measurements. The calibrated antenna ensures that the readings are consistent and can be compared to known standards.

2. **Why the other choices are incorrect:**
   - **A: A receiver with digital signal processing (DSP) noise reduction**
     - While a receiver with DSP can improve the quality of received signals by reducing noise, it is not designed to measure field strength. It lacks the necessary calibration and precision for accurate field strength measurements.
   - **C: An SWR meter with a peak-reading function**
     - An SWR (Standing Wave Ratio) meter is used to measure the match between a transmitter and an antenna system, not field strength. The peak-reading function is useful for measuring power peaks but does not provide field strength measurements.
   - **D: An oscilloscope with a high-stability crystal marker generator**
     - An oscilloscope is used to visualize electrical signals, and a crystal marker generator provides frequency markers. While useful for analyzing signals, this setup is not intended for measuring RF field strength.

In summary, a calibrated field strength meter with a calibrated antenna is the appropriate tool for accurately measuring RF field strength, as it is specifically designed and calibrated for this purpose.