What is the maximum bandwidth allowed for CW (Continuous Wave) transmission?

The maximum bandwidth allowed for Continuous Wave (CW) transmission is 150 Hz. This specification is in place to ensure that CW signals, which are typically narrowband, do not interfere excessively with one another and that they can be effectively distinguished from adjacent channels.

CW transmissions are distinguished by their simplicity and efficiency in terms of bandwidth usage. The narrow bandwidth requirement allows for more efficient use of the frequency spectrum, particularly in crowded bands where multiple operators are communicating. Operating within this bandwidth limit ensures that signals are clearly recognized and minimizes the potential for overlapping transmissions that could lead to difficulties in communication.

While the other options suggest bandwidth limits that are either narrower or wider than the actual regulation, the choice of 150 Hz aligns with the established standards in amateur radio practices. This standardization is crucial for effective communication and to maintain order within the amateur radio allocations.