A communications technician would perform a modulation-acceptance bandwidth test in order to:

The correct answer focuses on determining the effective bandwidth of a communications receiver, which is crucial for evaluating how well the receiver can handle modulated signals. When a modulation-acceptance bandwidth test is performed, it assesses the range of frequencies over which the receiver can accurately demodulate signals without significant distortion. This aspect is essential since different modulation schemes may vary in their required bandwidth and the receiver needs to be able to process these signals efficiently.

In practical terms, if the effective bandwidth is too narrow, the receiver may not be able to pick up all the necessary frequencies for proper communication, leading to potential loss of information or quality of the transmitted signals. Conversely, a wider bandwidth may allow more robust signal handling but could lead to increased noise. Thus, understanding and measuring the effective bandwidth through this specific test is essential for ensuring reliable communication in various environments.

The other options, while related to communications technology, do not directly pertain to a modulation-acceptance bandwidth test. For instance, measuring the power output of a transmitter deals more with the transmitter’s performance rather than the receiver's bandwidth capabilities. Assessing antenna efficiency focuses on how well the antenna converts the input power into radiated energy, and analyzing distortion levels relates to the quality of the signal rather than