Radio Orienteering

Amateur Radio Direction Finding (ARDF)

Welcome to Radio-O.  Here is how it works! We provide a radio receiver with a directional antenna, an orienteering map, a compass, and a finger stick. By pointing the antenna and listening to the signal you can determine the direction of the signal.  Using this information you navigate to the transmitter and punch in with your finger stick. Only the start and finish are marked on the map and it is important to keep track of where you are.  To qualify as finishing you must find at least one transmitter on your course and reach the finish within the time limit. To calculate results -- first; the number of assigned transmitters you found, then; your time on the course. We offer beginner through advanced courses, Regular BOK fees apply, and Pre-Registration is required.

Latest News in Radio Orienteering

May 23rd, 2023

Eno River Radio-O/ARDF 80m Classic, May 21, Results

This was highest number of entries Kelly and I have directed at a BOK ARDF event, 22 participants. We even ran out of the RFID card arm band holders that most people prefer and had to use a bunch of the bracelet holders. At least one participant wasn’t too happy about it. But for us […]

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May 15th, 2023

Receiver Rental for World Radio-O Champs in Czech Republic

If you need to rent one of our receivers for the World Champs now is your chance. BOK has exclusive option to rent them until June 26, and then we will offer the rental to others.

We only have 6 of the 2m receivers, and 8 of our usual 80m receivers, however we should be getting more of the OK2BWN receivers at the Champs that will go into our rental program.

80m Receiver Rental

2m Receiver Rental

May 12th, 2023

Open Radio-O/ARDF 80m Classic at Eno River State Park, May 21

We will have an 80 m classic course at the Eno River State Park Few’s Ford Access on Sunday, May 21, GPS 36.0742 -79.0055. For more information about Radio-O/ARDF, see the BOK ARDF page. Starts 10:00 AM to 1:00 PM. The course closes at 3:00 PM.

We will be using the Jiri Marecek transmitters, which are likely the same transmitters and antennas that will be used at the World Champs in Czech Republic.

In order to be sure we have enough rental receivers we will be renting them for a morning session from 10am – 12:30pm and from 12:30pm – 3pm. (If all the receivers aren’t rented then there may not be a 1.5hr time restriction.)

Directors: Patrick and Kelly.

Online registration is required here. Please register by Friday May 19. There is no need to sign up for a particular course. Everyone gets the same map. If you are renting a receiver, make sure to bring your headphones. We’ll be using Patrick and Kelly’s course timing system, so you will not need to bring or rent a finger stick.

There is no charge for the beginner class, but you must still register.

The check-in is near the parking area just north of the restrooms. Maps and any reserved equipment will be available there. From our meeting place, you will have to walk to the start and back from the finish, both of which are on the west side of the Eno River. YOU MUST NOT RUN ON THE BRIDGE!

Beginner class at 10 am – 11am: There is no charge for the class and that includes the receivers for the class. If you also want to go out on the course you will need to rent a receiver. (The class receivers aren’t sensitive enough to use on the course.)

Course notes. The entire course is on the west side of the Eno. The homing beacon is the finish. There is only one control to punch at the homing beacon and it is the finish. There is no finish shoot. Foxes will be on 3.52 MHz, homing beacon on 3.59 MHz. There is a 300m exclusion zone around the start and around each control.


1 fox1.6 km
2 foxes2.0 km
3 foxes3.2 km
4 foxes3.9 km
5 foxes4.3 km
May 3rd, 2023

Radio-O Practice at our Orienteering Events

We plan to have very short radio orienteering practice at most of our orienteering events before the World Champs in September. We’re doing this partly because BOK Radio-O’s competitors make up half the US Team for the World Championships this fall in the Czech Republic.  

The practice events closely resembling the competition conditions we have held are ideal training opportunities. On the other hand, just having frequent practices finding a few transmitters is important training because it helps to make the process automatic. Toward this end, Charles will set out a few transmitters at most of our Orienteering events before the World Championships for us to practice on. These will not be courses: no start or finish, no si-boxes, just transmitters and a flag. With only 15 – 20 minutes of Radio-O practice, you should have the time and energy to run your Orienteering course as well. 

Check the event article on the website to see what format is being set up and bring your receiver. (BOK receivers will be available without charge for these practices.) 

April 24th, 2023

ARDF USA Championship 2023 – Classic Day 2 Results

On the final day of the competition, we were greeted by below-seasonal temperatures (cold!) and rain. The roles were reversed from the day before: those who did 80m courses on Saturday did 2m on Sunday and vice versa. Many competitors were on a tight travel schedule, and the electrical storm delayed the course set-out schedule. […]

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