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Radio Society of Great Britain The scene viewed by a newcomer
The event was split into two activities: the first, in the morning/early afternoon, involved locating five 144MHz beacon transmitters (TXers) in a two-hour period. The second was a hunt for nine 3.5MHz beacons over a ninety-minute period.
Looking at the course map, you’d be forgiven for thinking that the tasks would be easy: the terrain was fairly flat and the wooded areas were not overly dense. However, the south Midlands had had a recent dump of snow, and it was was half a foot deep in some places on the course. Paths clearly marked on the map had vanished and, due to melting snow, unmarked streams appeared. That’s not to mention the semi-frozen mud. The challenge could have been designed by Ray Mears.
Anyway, I had a go at the 144MHz event and - with great difficulty - found two of the five ‘foxes’, TX1 and TX4. So far, not so bad. Then I lost my bearings...
One of the dangers of ARDFing on foot (as opposed to in a car) is that it is easy just to follow the signal and neglect to check your position on the map. Each of the five TXers sound for only 60 seconds at a time, so you’re left waiting around for a number of minutes if you don’t find your targeted fox within this short duration. Therefore, as you get closer to the beacon, the greater is the temptation to simply run in the direction of the transmitter in the hope of stumbling across it. I did exactly that. Although TX4 was located, I lost my ‘situational awareness’. This is a common problem for pilots who follow magnetic headings given to them by air traffic control instead of relying on their own navigation. The more turns a controller instructs an aircraft to make, the greater the risk of the pilot becoming unaware of his/her position relative to runways, other aircraft and - more critically - terrain. So, my advice to would-be DFers is, before moving directly toward a beacon, take a moment to determine your exact location and then take an accurate bearing of the TXer. This way, once the beacon is located, you can return to your known point on the map by heading on the reciprocal compass course. That’s easier said than done, given that terrain and vegetation rarely permit perfect bee-lines to be taken. Add to this the signal reflections and multi-path effects from the trees and the ground (especially on 144MHz), and it is all too easy to get disorientated despite taking all the precautions.
Unfortunately, I avoided taking any of these precautions, recklessly following the Morse ID for the number 4 beacon deep into a wood. Having found it, I needed to make my way back to the start of the course - the Bucknell Woods car park - before my two-hour slot had elapsed. No problem. I just had to follow the signal from the beacon erected at the starting point. But when I attempted to tune it in, there was nothing. Ah oh.....I really was lost. I knew that the car park was in a general easterly direction, so I took a pathway that headed east-southeast. The ‘dah-dah dah-dah-dah’ (‘MO’) of the base transmitter was eventually picked up, and I took a zig-zag course back to base. I was twenty minutes over time, had found only two transmitters, had shoes which were covered in mud, and I had come last. On the bright side, I didn’t lose any toes to frostbite and I learned a lot from the experience.
I sat out the 80-metre activity. (I was staggering through the car park as this was starting.)
The results of the event are on the website www.ardf.btinternet.co.uk/trial.htm. You’ll note the results for Jillian M6JIL, who participated in both W&DARS fox hunts. I (and Jillian) be at the next ARDF event, to be held near Aldershot on 7 March.
If you enjoyed the car-based urban fox hunts organised by W&DARS, you may want to give radio orienteering a try. Just remember that success in this activity is based mostly on skills in orienteering, not in radio. Having a ‘Worked All Continents’ plaque on your wall is no guarantee of victory. However, being comfortable with radio equipment and understanding propagation are definite advantages.
I have to say, ARDF is a true ‘radio sport’. Although contests of the like of ARRL DX is also included in Sport Radio, sitting on one’s behind for hours on end and drinking copious amounts of coffee (as I do, anyway) hardly fits the definition of ‘sport’, does it? With ARDF, you can exercise both the mind and the body.
For a good intro to radio orienteering, try the website www.ardf.btinternet.co.uk/hints.html. This will also help you prepare for the main event in the UK direction-finding calendar: the W&DARS fox hunt on 8 May.
Evan 2E0TJU
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