January 12th, 2003 will be the first ARDF event that LAOC has hosted, and it will be held at Vermont Canyon in Griffith Park. ARDF (Amateur Radio Direction Finding) is Orienteering with a twist; the control flags are not shown on the map and must be found using radio direction finding techniques, triangulation, and orienteering skills. The object is to find all the transmitters, and the winner is the person who does this in the shortest amount of time. A control flag and punch is located within 6 meters of each transmitter where, as in orienteering, the competitor punches their control card. An amateur radio license is not required to participate except to operate the transmitters.
The transmitters can be found in any order, although there will be one optimum sequence that will result in the shortest course and thus what also should be the shortest time! That sequence can be found by plotting the direction and signal strength of each transmitter on the orienteering map. Each transmitter is on for one minute and off for four minutes in round robin fashion and is identified by a unique Morse Code transmission. Transmitter #1 transmits MOE (-- --- .), #2 transmits MOI (-- --- ..), #3 transmits MOS (-- --- ), #4 transmits MOH (-- --- .), and #5 transmits MO5 (-- --- ..). It really is not necessary to know the Morse Code, just count the number of "dits" to identify which transmitter is on. The end of each transmission is signaled by the callsign in Morse Code of the transmitter owner.
Although two different frequency bands are used for ARDF, 2 meters (144 MHz) and 80 meters (3.5 MHz), I have chosen 80 meters to introduce orienteers to ARDF. Like orienteering, *many* skills are required to do well at ARDF, and 80 meters is an easier way to introduce new people to this sport. The beginners clinics at the event will explain this in more detail!
A concise description of an ARDF hunt is shown at http://www.rain.org/~marvin/ardf.htm. This was written by someone some years ago and placed on the web, and is an excellent demonstration of how an ARDF hunt works.
We will have DF equipment available for loan and there will be clinics to teach beginners how to use the equipment. Because of the limited amount of DF gear we have available for loan, it is requested that those people wanting to try ARDF email me at marvin@rain.org and let me know you are interested in participating. Hope to see you there!!!