Amateur radio bearings

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Participants in a fox hunt in the 2-meter tape
Channel

Amateur Radio Direction Finding is recognized internationally as Amateur Radio Direction Finding designated (ARDF) and colloquially fox hunting called. It is about the sporting area of ​​the amateur radio hobby .

overview

The aim of amateur radio direction finding is to use small, portable receivers to find small transmitters using radio direction finding, which are preferably hidden in a wooded area. Small transmitters with omnidirectional antennas are used, which are operated in the shortwave and ultra- shortwave amateur radio bands . The order in which these stations are started is not determined beforehand; so does the route selection, i.e. H. Planning your own running route between the broadcasters is one of the main attractions of this outdoor sport.

Usually five time-controlled transmitters are hidden, each of which alternately sends out a different Morse code for one minute : MOE, MOI, MOS, MOH, MO5. The transmitters all broadcast on the same frequency. Each transmitter can therefore only be heard for one minute every five minutes and can therefore be tracked. At the finish there is another transmitter that continuously transmits the identifier MO on a different frequency in the same frequency band so that the runners can reach the finish. Evidence that a transmitter has been found is provided by an item control system (electronically or with a stamping tool). Apart from a direction finder, only a terrain map and a compass are allowed as aids. The winner of a direction finding event is the one who can get from start to finish using all the transmitters in the shortest possible time.

In Germany, DF events are regularly carried out by the districts of the German Amateur Radio Club (DARC) and DF sports groups of the Association of Radio Amateurs in Telecommunications and Post (VFDB) as well as other regional DF sports groups. In Switzerland, various sections of the Union of Swiss Shortwave Amateurs (USKA) hold DF events. Furthermore, there are national championships, European and world championships in many countries. World championships are organized by the International Amateur Radio Union (IARU).

Although ARDF can be operated on all frequencies assigned to the amateur radio service, it is common for events to be held on the 2-meter and / or the 80-meter tape . 2-meter DF events are considered to be more difficult, as electromagnetic reflections can occur in the area, e.g. B. on mountain slopes. With amateur radio direction finding on the 80-m-band, you can almost always find the transmitter precisely in the entire area. Bearing errors can occur near fences, bridges, overhead lines, or other large metal objects. In the Netherlands there are also direction finding events in the 70 centimeter tape .

variants

sprint

In a sprint competition, 12 transmitters are in use: five transmitters with slower identification broadcast on the lowest frequency. Above that follows the intermediate post (Spector) and then five transmitters with fast identification follow on another frequency. The target fox can be heard on the highest frequency. Sprint means quick decisions: each fox only transmits 12 seconds, so that all five transmitters in a group can be heard within a minute. Although the runner receives an orienteering map (orienteering map), successful participants generate an image of the location of all transmitters in their heads while moving through the terrain. In international competitions, running times of less than 20 minutes are achieved for all channels.

Foxoring

Foxoring is a combination of orienteering and amateur radio arrows.

Geofoxing

Geofoxing is a combination of geocaching and amateur radio direction finders.

Fox migration

The fox hike differs from the classic fox hunt mainly in that the transmitters known as foxes do not have to be searched for for a long time. The foxes are designed from the start in such a way that a beautiful hike through nature results. The level of difficulty can vary depending on the participants. The aim is to find all foxes regardless of the time. The foxes have a letter that should be noted or memorized. At the “Zielfuchs” these result in a solution word. The fox migration can be varied in particular by adding GPS data to the foxes . So you can do the fox hike with a radio direction finder as well as with a GPS device. This is organized in a similar way to geocaching . In this version, too, the individual foxes have to be found in order to find the solution word at the goal. In the fox hike , the participants start a little later in order to give each participant the possibility of their own bearing.

Large-scale fox hunting

In a large-scale fox hunt, the participants take the bearings of a transmitter from home that is hidden in a large area. They transmit their bearing values ​​to a control station by radio. The control station can determine a target bearing value from the coordinates of the transmitter (known only to it) and the coordinates of each participant. The winner is whoever has achieved the smallest deviation between the target bearing value and the given bearing.

In addition, mobile tracking teams try to reach the location of the transmitter during the competition.

A large-scale fox hunt is carried out regularly in the catchment area of ​​the Zugspitz relay DBØZU.

Related sports

A related outdoor sport (but without the technical component) is orienteering .

literature

Web links

Commons : Amateur radio direction finding  - collection of pictures, videos and audio files

Individual evidence

  1. ↑ 18th World ARDF Championships 2016. In: ardf2016.com. August 31, 2016, accessed September 29, 2016 (Bulgarian).