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Rules for both the Car hunts and the ARDF hunts are posted on this page.

Car Hunt Rules

The following rules are for the Albuquerque Transmitter Hunters' traditional car hunts, designed to keep this a fun event for all. Revised May 4, 2010.



  1. The hidden transmitter signal must be copyable at the starting point by agreement among the hunters present. The start point is a small parking lot at the north end of Yale between the UNM North Golf Course and the Center for Non-Invasive Studies. Click here for a map (opens new window). Start times are 1PM on the first Sunday of each month and 9AM on third Saturday of each month.
  2. The talk-in frequency is the 146.90 (-, 67Hz PL) Albuquerque repeater, which is almost always monitored by hunters before, during and after hunts.
  3. The primary transmitter must be on 145.565 MHz and maintain constant power throughout the hunt. The antenna may be in any configuration, but the polarization must not change during the hunt. Secondary transmitters may be located on a different frequency, which may be announced to hunters upon finding the primary transmitter.
  4. The antenna and transmitter shall be within 500 feet of access by standard passenger cars in a publicly accessible area with no charge for admission. Reasonable care must be taken to ensure that hunters can safely get to the hidden transmitter and in the spirit of fun hunts, easy access to the transmitter via a traffic or safety hazard should be avoided by the huntmaster.
  5. The winner of the hunt is determined by the person/team who finds all transmitters hidden with the lowest miles driven. Odometer readings are taken by one of the hunters at the start point, and are then used to calculate the mileage driven by each participant at the end of the hunt. The winner becomes the next huntmaster.
  6. The hunt boundaries are the edges of the latest Rand McNally map of Albuquerque, New Mexico. However, Sandia Crest, military reservations, private property and Native American reservation lands are out of bounds.
  7. Rule Modifications: The following rule modifications must be announced at least a week before a hunt if such a modification is deemed necessary by the huntmaster:
    • Any boundary extensions, which must be specified.
    • Intermittent signals with less than 10 seconds of "on time."
    • Any off-road distance extensions, which must be specified.
    • Any variations to "minimum mileage wins" rule, which must be specified.
    • Any change of the primary transmitter frequency, which must be specified.


ARDF Rules

Because no official rules exist for IARU Region 2, The ARDF practice sessions held by the Albuquerque Transmitter Hunters uses this set of rules.


Revised May 13, 2010.

80 meter DF demo for W5JBP at 2001 USA ARDF Champs



These rules are for use at ARDF practice sessions held by the Albuquerque Transmitter Hunters and the Albuquerque Amateur Radio Club. 

These rules are designed to support the development and growth of the sport of ARDF in the US.  Significant rule modifications shall be communicated to participants before the event. 

The course setter must have a valid ham radio license for the band in use, All transmitters shall ID per FCC requirements. COMPETITORS do not need a ham license as they are only receiving.  



Competition is open to all  (ham license not required for receiving, Orienteers are welcome).  However our land use permit ( old south 14 ARDF site) with the City of Albuquerque Open Space Division requires us to get approval if the number of attendees exceeds 20. Please contact us in advance if you plan to compete. No formal awards are given at the practice sessions. Results shall be posted on this (or) the event website.

The age categories are as follows: 


Women (D) Men (M) Age
D19 M19 19 and younger
D21 M21 Regardless of age
D35 M40 35/40 and older
D50 M50 50 and older
--- M60 60 and older

Competitors belong to the M19 or D19 category up to the end of the calendar year in which they reach the age of 19. 

Men competitors aged 40 or older or women competitors aged 35 or older belong to each category at the end of the calendar year of the event. 


A. For ARDF hunts held at NMO meets, the standard NMO meet fee schedule is charged by the Orienteering club. This covers land use fees that NMO has to pay for use of the venue, map printing and insurance provided by USOF. A forest service parking fee is required at some NMO locations.

B. for hunts held on non NMO maps ( other sites) A fee may be charged to cover the cost of publishing the map and control card. This is normally less then $2 (depending on where we get the map printed).



C1. General

RDF Championships shall take place on two amateur bands, namely 3.5 MHz and 144 MHz. Bands are alternated between each session. I.E. one month its VHF and the next month its HF. The band is announced in advance of the hunt via the abqardf list server. Additional sessions nay be held during the month to allow a VHF followed by a HF hunt to occur as we near a national champion ship date.

For national meets one meet day shall be a VHF race and one day shall be a HF race. VHF and HF Days are announced in advance of the meet.

It is absolutely forbidden to give or take any assistance from or to any person, including competitors, and also to utilize any means or method of transport. The penalty for both shall be disqualification. However competitors are expected to provide emergency assistance or first aid to another competitor when needed:  no competitor will be disqualified for providing such assistance so long as they gain no competitive advantage by doing so. 

The use of GPS receivers for navigation is not allowed. It is considered receiving assistance. No GPS devices are allowed on the course (national or region II meets) by any competitor. Course setters or event personal may use GPS devices.

Competitors shall not inflict loss or damage on or to the property of any other person or the venue.

Competitors take part in all competitions at their own risk. All Competitors will be required to sign a waiver form (NMO waver form when hunts are held at NMO meets. Albuquerque transmitters hunters waver form for all other AARC meets).

C.2 Technical


Each course will have at least 5 transmitters. Minimum distance between transmitters is 400m, and the transmitter closest to the starting point should be at least 750m away. Total course length from start to finish, via all transmitters, should be between 4 and 7 km. 

In the event of a thunderstorm, the course setter is entitled to recall the competition immediately.

Each transmitter will be marked with a marker or flag within 2 meters.  Although the standard red and white triangular prism is recommended, any unique, brightly colored marker is acceptable. All prisms must be identical, and a sample must be displayed at the starting point. The transmitter number shall be marked on the prism.  The prism must be at least 1 meter above the ground and visible from at least 10 meters away.

Transmitters must be operated within the regulations of the country where the event is taking place. Frequencies shall be chosen in accordance with the local band plan. 

Antenna patterns will be omni directional in the horizontal plane. Vertical polarization will be used on 80 meters. Horizontal polarization will be used on 2 meters. 

The standard MOE/MOI/MOS/MOH/MO5 sequence will be used. For US national meets or region II meets a finish line beacon sending MO on a different frequency shall be used for both the 80-meter and 2 meter hunts. For local meets or practice meets the use of a finish line beacon sending MO on a different frequency is optional.


3.5 Mhz
(80 Meter band)
144 Mhz
(2 meter band)
Note: Frequencies may change as we near a national championship to the ones used for the championships. Changes will be announced well in advance.

Carrier frequencies:

Hidden transmitters:
3579.5 KHz. 

Homing Beacon (optional for local meets and may not be used):
3546.8 KHz. 

Power Level: Output power shall be between .02 - 5 Watts. 

Modulation:  CW (A1A) will be used. 

Antenna:  Vertical wire with radials 

Carrier frequencies: 

Hidden transmitters:
145.565 MHz 

Homing Beacon (optional for local meets and may not be used):
144.890 MHz 

Power level: Output power shall be between 0.15 - 1 Watts. 

Modulation:  MCW AM Keyed carrier. . 

Antenna:  Omni directional horizontal (turn style) 


Transmitters shall be searched by each category as follows. 

  • M21 category shall search all five transmitters
  • M19 category shall not be scored for transmitter number 3 (MOS)
  • M40 category shall not be scored for transmitter number 5 (MO5)
  • M50 category shall not be scored for transmitter number 2 (MOI)
  • D19 category shall not be scored for transmitter number 2 (MOI)
  • D21 category shall not be scored for transmitter number 4 (MOH)
  • D35 category shall not be scored for transmitter number 1 (MOE)
  • D50 and M60 shall not be scored for transmitter number #4 (MOH) and # 1 (MOE)


Each competitor shall provide her or his own equipment.  However some equipment may be available for loan. Please contact us in advance.

Requirement for official document giving date of birth removed form rules since these are only practice sessions. 

Competitors will be using sport ident E-sticks. The e-stick must be registered (dibed) at each transmitter SI station, and downloaded at the finish line. We have converted to the use of Sport Ident an electronic orienteering punching system, paper tickets are being used as a backup or if someone does not have an SI stick. Transmitters may be found in any sequence. 

The host society will establish procedures for starting order, start corridors, waiting areas, control of equipment, etc., as appropriate. The rules from other IARU regions serve as a model. The rules must be easy to understand and follow for all participants. 

Timeout: The maximum time allowed on the course shall be announced before the start of the course, and will be at least 3 hours. Any competitor exceeding this time shall be disqualified. The host organization may also, at their discretion, modify the timeout period the day of the event to take into account for any unexpected situations such as weather. The timeout period may not be modified once the event has started.