Smiths Reef Night ARDF

Saturday 15th November 2008

In conjunction with the night orienteering event held by Nillumbik Emus, we decided to try a night RadiO course of their own. After much discussion with club members, we decided that the main format for the night would be a 2m ARDF course, following international rules (750m exclusion circle, transmitters at least 500m apart), and with total course distance being approximately 7km. For an added challenge, Rex Niven, the course setter for the orienteering course, kindly allowed us to show six of the orienteering controls on each competitor’s map, so that, as an added challenge, people could choose to find some or all of these as well as the ARDF transmitters. It was a perfect map for such an event – there were hills, but not so many as to make the reflections overwhelming or the terrain unrunnable, and the bush was very open, making beeline navigation between transmitters almost a viable option!   Now, as we’ve never run an ARDF course at night before, and had no idea how difficult such an event would prove, we made a few changes to how we set up the course.

  1. Joyce kindly provided us with some reflective tapes, which we attached to the ARDF flags so that, as is the intention during the day, if you got reasonably close, you had a good chance of finding the transmitter. These things were incredible! You could see them from a mile away and they reflected so brightly, that it was easy to mistake them for other people’s torches!
  2. We also placed 5 2m Fox-Ors, transmitting on 144.250 MHz, out on the course. Their purpose was twofold. First, those that did not feel confident about completing an ARDF course at night could instead just complete the Fox-Or. Secondly, we placed the ARDF transmitters into the same 200m circle as the five Fox-Or-ing controls. The theory was that if people got close to the ARDF transmitter but couldn’t quite find it, then they could use the continuously transmitting Fox-Ors to zero in on them a bit. In future events, we probably won’t do this. Some people chose not to use the Fox-Ors and complete the ARDF course in the traditional way, while those that did felt they could have coped without them.
  3. On each transmitter, we placed a segment of the map showing the 200m circle that the transmitter was located in. If people had lost contact with the map, which is a common occurrence even during the day, let alone at night, then they could use this segment to help them relocate themselves.
  4. We placed the transmitters so that getting them in order was the most efficient route. Not everyone realised this, but for those that did, it meant less zig-zagging around than on some of the ARDF courses.
  5. We asked everyone to return at midnight, with everyone starting no later than 9:05pm. Without the usual 90 or 120 minute time restrictions, we figured people would be able to take their time and find the transmitters without feeling the need to rush back to the start.

  We had great turnout for this event – ten competitors. Starting most people off at 9pm, except for a couple of stragglers that started a couple of minutes later, we settled down to wait for the verdict. David had just managed to lodge the homing beacon up a nearby tree when Rex, our fellow orienteering course setter, expressed an interest in night ARDF, saying he had tried the format in the past but without a great deal of success. Figuring most people wouldn’t be back for a while, we headed off with him to give him some moral support as he found a couple of the transmitters. He enjoyed himself, and managed to find 3 transmitters in the 2 and a half hours or so that he was out on the course. And he drew some extremely accurate bearings in the meantime, too – two of which crossed perfectly on Tx2’s location.   After an hour or so out on the course with Rex, however, I had that uncomfortable feeling that we’d forgotten something… Racking my brains, it finally hit me – although the homing beacon was in the tree, it wasn’t actually ON! I rushed back to the start with my rapidly flattening torch batteries to turn it on – and lucky I did, because not only did Adam beat me back to the finish (having done all the ARDF transmitters and a couple of O controls in just over an hour – brilliant effort, before returning to drop off his sniffer and heading out again to get the rest of the controls), but also Bryan was not far from home when I arrived! It’s worth mentioning that not only did Bryan find all the ARDF controls without a compass and without tuning in to the colocated Fox-Ors, but he also managed to find his way back to the finish the old fashioned way – navigating by the stars – since I only turned the homing beacon on about 10 minutes before he got back. Well done, Bryan, and sorry about the delay!   Other competitors returned later, with most enjoying their run and finding what they’d set out to get. Bruce, Mark, Geoff and Gary all found the five ARDF controls, with Bruce finding three of the orienteering controls as well, despite taking out a northern hemisphere compass! Ryordan and Darian went out together and found all five of their Fox-Ors while Suzanne headed out to get a couple of the Fox-Ors and some orienteering controls as well. Peter M had a bit of difficulty, but still found two of the ARDFs and two orienteering controls, so well done to him! No-one noticed the echidna which had been making itself comfortable at transmitter four when we put the controls out, so perhaps it had moved on by the time everyone arrived.   All in all, night ARDF seems a promising concept. No-one got too badly lost and, provided the terrain is good, it looks like people can still complete fairly accurate and rapid runs. The colocation of Fox-Oring controls is probably unnecessary, so I don’t think we should repeat that next time around, but other than that, I recommend the format to people looking for a course to set in the future!  

 CompetitorTimeARDF Controls  
Adam Scammell1:09:095
Bryan Ackerly1:18:025
Gary Panter2:02:015
Mark Besley2:43:115
Geoff Hudson2:47:285
Rex Niven2:15:003
 CompetitorTimeARDF ControlsO Controls 
Adam Scammell1:25:0056
Bruce Paterson2:01:2053
Peter Maloney2:24:1522
 CompetitorTimeARDF ControlsO Controls 
Ryordan/Darian Panter2:17:5050
Suzanne O’Callaghan1:57:2023