ARDF stands for Amateur Radio Direction Finding and it is a radio sport in which the participant has to locate a number of small, low power transmitters in a wood or open terrain such as a country park or heathland.
The legal and insurance impediments to car based direction finding (see the RSGB Handbook 2024 page 97) make pedestrian DF appropriate
ARDF is an international activity promoted by the IARU and using a common set of rules and frequency bands across the World. The two bands used are 3.5MHz where surface wave propagation dominates and 144MHz where space wave propagation dominates. The different propagation mechanisms give different problems to the competitor on the two bands.
Three types of competiton have evolved:
The Classic race deploys five transmitters all operating on the same frequency but not all at the same time. The transmitters start transmitting for exactly one minute, one after the other in a five minute cycle.
The Sprint format (only 3.5MHz is used for this) has a total of ten transmitters in two groups of five on different frequencies. Each transmitter sends for 12 seconds in a one minute cycle with the two groups transmitting at the same time as each other on their respective frequencies.
The final format is FoxOring a half way house with Orienteering; again this uses only the 3.5MHz band. A series of circles are marked on the map and there is a transmitter located either in or near the circle. The very low power transmitters send continuously and soon become inaudible as the competitor moves away from one.
The transmitters all radiate an identifying modulation in a defined format.
The big National and International competitions categorise competitors by age so that you will be competing against someone in the same 10year (usually) age band.
Refer to the Rules pages for more details.
The 'Tonight at 8' video
To quickly get an idea of what is involved and a taste to the excitement and fun of competing at ARDF here is a link to the 'Tonight at 8' YouTube video:
The first part goes through a lot of detail about the equipment needed, event formats and so on. The best bit starts at 26 minutes into the video where there are a sequence of video clips that show participation through the eyes of a competitor. By the time you get to the 45 minute point, you will have an excellent idea of the radio fun to be had with ARDF
The ARDF Reflector
You can use this reflector to have the news items about ARDF delivered to your mail inbox. This avoids the need to keep checking the news page on the ARDF pages of the RSGB site.
The address of this reflector is RSGB-ARDF@groups.io
To join just go to the E Mail page RSGB-ARDF@groups.io, select the home page and click the tab 'Join the Group'.
The Group is also a medium for feedback and discussion of all RSGB ARDF 'happenings'.
The Links on the left of this page
These are self explanatory and are the route to further information. Perhaps the most important is the events page which is generally updated early in the year.