What tool can be used to determine the location of an amateur radio signal?

A directional antenna is specifically designed to focus in a particular direction, which enhances the ability to locate the source of a radio signal. By adjusting the angle of the antenna, an operator can determine the direction from which the strongest signal is received. This technique, often referred to as triangulation when used in conjunction with multiple receiving points, helps in accurately pinpointing the location of the transmitting amateur radio signal.

Using a map of licensed users or a frequency chart provides contextual information about who may be operating on certain frequencies, but it doesn't provide a direct method for finding the source of an active signal. Similarly, an online frequency monitor tracks signals but does not offer the directional capabilities needed for locating a specific source. Thus, the inherent design and functionality of a directional antenna make it a critical tool for locating amateur radio transmissions.