*Question G4B08:
What transmitter performance parameter does a two-tone test analyze?*  

*Correct Answer is  A: Linearity*  

### AI Response: (may contain errors)  

The correct answer to the question is **A: Linearity**.

### Explanation of the Correct Answer:
- A two-tone test is used to evaluate the linearity of a transmitter's output. 
- Linearity refers to how well the output signal corresponds to the input signal without distortion. 
- In a two-tone test, two different frequencies are transmitted simultaneously, and the resulting output is analyzed to see how well the transmitter maintains the relationship between the input and output signals. 
- If the transmitter is linear, the output will primarily consist of the two original tones without significant distortion or unwanted harmonics.

### Why the Other Choices are Incorrect:
- **B: Percentage of suppression of the carrier and undesired sideband for SSB**
  - This choice relates to Single Sideband (SSB) modulation, where the focus is on suppressing the carrier and unwanted sidebands. The two-tone test does not specifically measure this suppression.
  
- **C: Percentage of frequency modulation**
  - This choice pertains to frequency modulation (FM) and how much the frequency varies with the input signal. The two-tone test does not analyze frequency modulation characteristics.
  
- **D: Percentage of carrier phase shift**
  - This choice involves the phase relationship of the carrier signal. The two-tone test does not measure phase shift; it focuses on the linearity of the amplitude response.

### Summary:
- The two-tone test is primarily concerned with assessing the linearity of a transmitter's output, making **A: Linearity** the correct answer. 
- Understanding the purpose of the two-tone test helps in recognizing the importance of linearity in maintaining signal integrity in communications.