ARRL Technician Practice Exam 2025 – 400 Free Practice Questions to Pass the Exam

For reducing noise and interference during Continuous Wave (CW) reception, a narrower receive filter bandwidth is typically most effective. A bandwidth of 200 Hz is ideal for receiving CW signals since it allows for the detection of the desired signal while minimizing the reception of adjacent signals and reducing overall noise.

Selecting a bandwidth of 500 Hz is also appropriate, as this width still provides an effective compromise between signal clarity and the ability to capture the necessary frequency variations of a CW transmission. This bandwidth can help in achieving a good level of signal reception while filtering out most of the unwanted noise, making it a commonly used choice for CW operation.

Choices with a bandwidth of 1000 Hz or 1500 Hz are wider and can capture more noise and interference from adjacent signals, which can degrade reception quality for CW signals. Such wider bandwidths would not effectively minimize noise and are less suitable for the critical needs of CW communication, where clarity and signal integrity are paramount.