ARRL Technician Practice Exam 2025 – Complete Prep Guide

A valid US amateur radio station call sign follows specific conventions established by the Federal Communications Commission (FCC). In the United States, call signs consist of a prefix that indicates the license class and location, followed by a combination of letters and numbers.

The correct answer, W3ABC, adheres to these guidelines. The "W" prefix indicates that it is a call sign registered in the United States, while the "3" signifies it is assigned to a specific region (the Third Call Area). The "ABC" portion is a combination of three letters, which is permissible in a call sign.

The other options do not meet the requirements for a valid amateur radio call sign. For example, the first option includes numbers in a format that does not conform to the allowed structure. The third option has a combination of numbers and letters that do not align with standard call sign practices. Lastly, the fourth option begins with a "C" and includes a number that may indicate a foreign or invalid format. Thus, W3ABC stands out as the only valid call sign among the choices provided.