What is T-Hunting and ARDF?
Transmitter Hunting (also known as T-Hunting, fox hunting, radio direction finding) is a popular activity among Amateur Radio operators where a transmitter - usually on the 2-meter band - is actually hidden somewhere and is "hunted" (found) using radio direction finding techniques. The transmitter is usually on the air intermittently, and automatically identifies either in Morse code or voice. Amateurs participating in transmitter hunts start at a common start point (click here for a map to the start point used in Albuquerque), and the fun begins!
When the transmitter is on the air, the hunters "take bearings" using directional antennas by determining the direction where the signal is the strongest. This is done throughout the hunt until the transmitter is found. Usually, driving to the immediate area of the hidden transmitter is part of the game. One there, the remainder of the hunt takes place on foot while you "sniff" out the actual location of the hidden-T.
To put a rumor to rest, you do not need expensive equipment for transmitter hunting! All you need is a 2-meter receiver (an HT will do), an attenuator and a directional antenna (yagi, quad, etc.). Other items that can help, but aren't necessary, are a laminated map of Albuquerque, a compass, a protractor and some refreshments! Most of the equipment just mentioned can be built for a rather cheap price, and it performs exceptionally. Be sure to check out the homebrew equipment plans found on this website.
Transmitter hunting is both a fun and a serious activity. The "winner" of a an Albuquerque transmitter hunt is determined by the person who finds the transmitter with the least amount of mileage driven. The winner is then the person who hides the transmitter on the next hunt (know as the huntmaster). T-Hunters also use their skills to locate downed airplanes, boaters in distress, and sources of radio interference, unlicensed operators and jammers. T-hunters use competitions like our bi-monthly hunts to test their equipment and practice their skills in preparation for more serious situations.
Amateur Radio Direction Finding (ARDF)
ARDF is an increasingly popular flavor of T-Hunting that takes place on 80-meters as well as 2-meters. These types of hunts usually take place in large parks and forested areas. Unlike traditional T-hunting where driving is involved, ARDF hunts take place only on foot and require some orienteering skills. Participants are grouped in age categories, which determine the number of transmitters they are required to locate. Five transmitters are tuned to the same frequency and transmit in sequence, each of them on for a minute. The object is to find the number of transmitters required (according to the age category the hunter is competing in) in the quickest time possible, and without timing out. A maximum time is set, usually around 2 hours, to finish the course, otherwise the competitor is disqualified. Usually the 2-meter hunt takes place on one day, and the 80-meter hunt on another.
Participants of an ARDF event are shuttled to a designated common start point, and all of their equipment is impounded until the moment each are assigned to be individually launched from the start point. At that time, they are given a standard orienteering map of the area and a control card, and then launched. The clock begins for that particular competitor. After running a minimum distance, the participant is allowed to switch on his or her DFing equipment and take bearings of each of the transmitters they are required to find as they transmit in sequence. They may use no equipment that can give them or other competitors an unfair advantage, such as transmitting equipment, GPS receivers, cameras that produce instant photography, etc. we are now using SPORT IDENT AKA EPUNCH for score keeping. Please let us know your SI stick number in advance.
Each transmitter has a standard orange and white orienteering flag hanging overhead so it is visible a short distance away. Attached to the flag is a standard orienteering punch, which is essentially a paper punch with needles arranged in a unique pattern, used to punch control cards. When a participant finds a transmitter, he or she punches their control card to prove that they physically found the transmitter. Then they take off and located the next one. After all of the required transmitters have been located, then they must run to a designated finish point, which is denoted on their map. The finish point has a transmitter on a seperate frequency that is used solely as a homing beacon ( USE IS OPTIONAL for non national meets), in case a hunter becomes disoriented in the field. When the competitor crosses the finish line, his or her finishing time is recorded, and is ranked among the other competitors. Usually the first three competitors in each category receive a prize, depending on the event.
The Albuquerque Transmitter Hunters and the Albuquerque Amateur Radio Club proudly hosted the first United States ARDF Championship in Manzano State Park, located in the beautiful Manzano mountains in the summer of 2001. Over 30 participants from across the USA, Ukraine, Australia and China participated and had a wonderful time!
The Albuquerque Amateur Radio Club is currently holding practice sessions once a month at our mountain venue's in the northern end of the Manzano mountains just east of Albuquerque. We are using a 1:15000 scale 5 color orienteering map for ARDF site 1 and a 1:10000 scale 5 color orienteering map for ARDF site 2. Per international ARDF rules, 5 controls set on our hunts. Yes you can find the finish with out a homing beacon!
For VHF hunts the canyons at the sites provides excellent multipath training. The site also allows setting long 80 meter courses with elevation changes up to 440 feet depending on the layout of the course. If you are going to be in the Albuquerque area please contacts us for more information for session dates.