page_title: Amateur radio direction finding
section_title: Entry categories
hierarchical_section_title: Amateur radio direction finding / Description of competition and rules / Entry categories
caption_attribution_description: An ARDF competitor in the W19 category on an eighty meter course. Receiving equipment for the eighty meter band is generally more compact and lighter than equipment for the two meter band.
context_page_description: Amateur radio direction finding is an amateur racing sport that combines radio direction finding with the map and compass skills of orienteering. It is a timed race in which individual competitors use a topographic map, a magnetic compass and radio direction finding apparatus to navigate through diverse wooded terrain while searching for radio transmitters. The rules of the sport and international competitions are organized by the International Amateur Radio Union. The sport has been most popular in Eastern Europe, Russia, and China, where it was often used in the physical education programs in schools.
  ARDF events use radio frequencies on either the two-meter or eighty-meter amateur radio bands. These two bands were chosen because of their universal availability to amateur radio licensees in all countries. The radio equipment carried by competitors on a course must be capable of receiving the signal being transmitted by the five transmitters and useful for radio direction finding, including a radio receiver, attenuator, and directional antenna. Most equipment designs integrate all three components into one handheld device.
context_section_description: Although all competitors at an ARDF event use the same competition area and listen to the same set of five transmitters, they do not all compete in the same category. Current IARU rules divide entrants into different categories based on their age and gender. Only the M21 category must locate all five transmitters, while the other categories may skip only a specified transmitter or transmitters.
  M19—Men ages 19 and younger, 4 or 5 transmitters
  M21—Men of any age, 5 transmitters
  M40—Men ages 40 and older, 4 or 5 transmitters
  M50—Men ages 50 and older, 4 or 5 transmitters
  M60—Men ages 60 and older, 3 or 4 transmitters
  M70—Men ages 70 and older, 3 or 4 transmitters
  W19—Women ages 19 and younger, 4 or 5 transmitters
  W21—Women of any age, 4 or 5 transmitters
  W35—Women ages 35 and older, 4 or 5 transmitters
  W50—Women ages 50 and older, 3 or 4 transmitters
  W60—Women ages 60 and older, 3 or 4 transmitters
caption: An ARDF competitor in the W19 category on an eighty meter course.