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

February 18th, 2020

Open ARDF Ranking Event & Expert Long Form Orienteering at Umstead North

This is preliminary information. Stay tuned for updates.

  • When: March 15, 2020 Courses open from Noon – 3:30 pm
  • Location: Umstead North, Sycamore Creek Parking Area

We will have Beginner ARDF (Radio-O) through Expert ARDF as well as Expert Long Orienteering courses.


The Beginner and Intermediate ARDF courses will use the low power transmitters on a 2.5 minute cycle. There are 5 foxes and an Effective Length of 3.7k. Effective_Length=Length+(Climb*10) . Each transmitter will be on for 30 seconds before the next one starts. That is plenty of time to get a bearing and you don’t need to wait so long for it to come back on again.

We will have 80m Receivers for rent and instruction on how to use them throughout the event. This is a good event for you to try out Radio Orienteering because we are offering a classic beginner course.

Expert ARDF Ranking Event

This will be an ARDF Ranking Event for the following Categories:

  • ARDF Red 5 Foxes – Effective Length 8k, 5 Foxes
    • M40, M19
  • ARDF Green L 5 Foxes – Effective Length 7.7k, 5 Foxes
    • W21
  • ARDF Green S 4 Foxes – Effective Length 7.2k, 4 Foxes
    • W19, W35, M50
  • ARDF Brown L 3 Foxes – Effective Length 5.7k, 3 Foxes
    • W45, M60
  • ARDF Brown S 3 Foxes – Effective Length 4.7k, 3 Foxes
    • W55, W65, M70 

The Advanced and Expert ARDF courses will use 3 watt transmitters and they will be on the standard 5 minute cycle with each transmitter on for 1 minute at a time.

Long Form Orienteering

Long Form Orienteering has long legs and fewer controls. Route choice is thus more important.

There will be a 9.1k Red course with 6 legs ranging from 800m to 2.4k. The 7k Green course with 5 legs is similar except for one short 600m leg. The Brown course is a 6 leg classic format at 3.9k. Unfortunately it doesn’t lend itself to the long form.

December 18th, 2019

Dix Sprint & FoxOring Jan 5

We will start in Dorothea Dix Park in Raleigh near the intersection of Umstead and Whiteside drive. 35.769774, -78.657912. Park in the large lot south of Umstead Drive.

We will have a fast complex sprint with 4 courses, each with about 15 – 20 controls. Two red courses, each about 2.8k and two brown courses, each about 1.8k.

In addition we will have a FoxOring Radio Orienteering course. This starts out like orienteering, however your control, the Radio Transmitter, is about 60 meters from the orienteering control. You find it by using your radio receiver. If you are doing the FoxOring course you should rent a Receiver ($5) when you register if you don’t have one.

  • Event Types:
    • 2 Red and 2 Brown Sprints
      • You can do 2 reds, 2 browns, or a red and brown
    • FoxOring Radio O
      • You can do this before, between, after or instead of the sprints
  • Start Times: 10 AM – 12:00 PM
  • Course Closes: 1:00 PM

Registration is open in our store.

December 8th, 2019

Dix ARDF & Middle 12/8/19

Nice cool weather and we had new people trying ARDF. The 30 second transmit for the slow side of the sprint worked really well, particularly for new people and those who haven’t practiced in a while. Here are the results   Dix Park ARDF & Middle, Dec 8, 2019 – Open, Results 2019-12-08   Slow […]

Read More
December 3rd, 2019

Dix ARDF Sprint & Orienteering Dec. 8, 2019

This event will have 2 levels of ARDF (Radio Orienteering) and two lengths of Regular Orienteering. You can mix and match however you want.

  • Location: Small shelter at 1800 Umstead Drive
    • GPS 35.771397, -78.661485
  • Date: December 8, 2019
  • Time: Starts 11am – 1pm
    • Course closes at 2pm
  • Type: ARDF Radio Orienteering Sprint & Orienteering Middle Distance
    • Everyone is welcome
    • We will have a class at 11:30, and additional ARDF help throughout the day.
  • Registration: You must register in advance at the BOK store by Friday evening December 6th.
  • Orienteering Courses: High speed Middle Distance courses. Green 5.5k and Brown 3.7k. These courses are all in the open park, no need for
  • ARDF Courses: ARDF sprint courses are designed in two halves. You set your frequency and then start and find 5 controls. Next you change your frequency and find the Spectator Beacon which is the control that divides the two halves. Then you change frequencies and find the next 5 controls. Finally you change frequencies, find the Finish Beacon and run in to the Finish.
    • First Half : “Slow” In usual ARDF sprints each transmitter is on for 12 seconds and then the next transmitter comes on. This makes it particularly difficult for beginners to get the bearing. So we are going to set the first half so the transmitters will be on for 30 seconds before the change to the next transmitter.
    • Second Half: “Fast” This will be the standard 12 second transmitter transmit time.
    • Options for your courses:
      • Just Slow: Start as usual then after you punch the Beacon you then punch the finish
      • Just Fast: Start as usual then after you punch the Beacon you then punch the finish
      • Both: Start as usual, punch all the slow controls then the Beacon then punch all the fast controls. Punch the beacon again and then the finish.

The courses will be short probably about 4k for both together. We will update this after the course design is finalized. This is longer than usual because the slow side has 30 seconds on instead of 12 seconds. We are intentionally making the slow side longer than usual but much shorter than a classic event.

We will have ARDF instruction throughout the event. If you get started and are having trouble you can return for help and start over if you wish.

We have 6 receivers that we can rent so sign up early to reserve one. When someone returns we can give the receiver to someone else. We will confirm that you have a receiver after you enter. If you are on the waiting list for a receiver you should come at Noon so someone with a receiver has a chance to return.

October 20th, 2019

Open Radio-O/ARDF event at Eno River, Sun. October 27.

We’ll have rain but the event is still on!

We will have an 80 m classic course and a short foxoring course at the Eno River State Park Few’s Ford Access on Sunday, October 27. For more information about Radio-O/ARDF, see the BOK ARDF page. Starts 10:00 AM to 2:00 PM. We will have a class at noon. The course closes at 3:00 PM. Remember there is a $5 fee if you need to rent a receiver. Also, parking fills up fast at the Eno River State Park; car pooling is appreciated.

Open event with pre-registration: Newcomers welcome — you don’t have to be a BOK member. Here is a link to the BOK store event registration. Groups of 5 or more separate entries may register using the group registration procedure. Please register by Friday evening, Oct-25.

Courses provided: There are two types of course, 80 m classic and a beginner foxoring. Getting 5 classic foxes will require a minimum of 5.5 km. Getting 2 foxes a minimum of 2.2 km. The foxoring course has 7 controls you can search for. Getting all of them will require a minimum of 2.7 km.