Mobile transmitter hunts are organized events where participants travel exclusively or primarily in motor vehicles.
A regulated sport form of transmitter hunting by runners on foot is called Amateur Radio Direction Finding, known worldwide by its acronym, ARDF.
ARDF is a timed race in which individual competitors use a topographic map and a magnetic compass to navigate through diverse, wooded terrain while searching for hidden radio transmitters.
This type of hunt enables participation by contestants who are unable to travel, such as people with mobility issues, minors, school groups, etc., and requires a greater level of skill and coordination.
Special design considerations include adequate strength to withstand the wind at highway vehicle speeds and ease of repair after collisions with overhead tree branches.
Some radio direction finding equipment popular with mobile transmitter hunters operates on the time difference of arrival principal.
Advanced units can use a compass or GPS receiver to compute a direction relative to the instant motion of the vehicle.
Attenuators are most often used when approaching the near vicinity of a transmitter, in order to keep the received signal strength within a usable range.