<< Ortovox M2? | Digital Beacons | Barryvox Opto 3000 >>
The French company of Nic-Impex have been in the avalanche beacon business for a long time. In 1998 their Arva 9000 beacon was one of the first fully digital units on the market. Instead of a searcher homing in on an avalanche victim by interpreting sonar like peeps the beacon gives distance and shows when the searcher was heading in the right direction.
Old and New ARVAs
The ARVA 9000 has a number of disadvantages. Having only a single antenna it is not truly directional. A user has to sweep the unit through an arc in order to lock onto a signal, this corresponding to an oval flux line transmitted by the victims unit. More importantly the unit is slow and did not indicate if there was more than one victim. Something that is important for rescue workers arriving on an avalanche scene. In theory the digital readout should take away the problems of interpreting signals but the lack of power of the original 9000 meant that searchers had to keep a cool head and be methodical. Not easy in the immediate panic after an avalanche.
The ARVA 9000 Evolution improved processing speed and also had a multi-victim indicator but it was still a generation behind the directional Tracker DTS and Barryvox Opto 3000 beacons so last year Impex sat down with members of the rescue services, guides and the French Alpine Club (CAF) to look at what they wanted out of a beacon. The result of this consulting process is the ARVA A.D.vanced. A few weeks ago Impex sent us a unit to test out.
As owners of Impex Arva 8000? and 9000 beacons we like their simplicity and this heritage is obvious when using the A.D.vanced. Impex started with two aims: give recreational users the best chance of finding a single buried victim at the same time as offering advanced users features to assist in multi-victim searches. They also wanted to improve on the current reference, the Tracker DTS.
The first thing you notice when switching the A.D.vanced to search mode is the speed. It reacts very quickly, no more stopping and starting as the beacon catches up. Due to power constraints, a beacon needs to run for over 200 hours on a set of batteries, it is not possible to equip beacons with the kind of microprocessors found in home computers but with the A.D.vanced Impex has opted for a 16 bit processor rather than the standard 8 bit. Put simply this enables the beacon to manipulate information twice as fast for the same speed processor. This is important, in the stress of a real search you want the beacon to work as fast as you, particularly in the final search phase.
As with other modern digital beacons the A.D.vanced is fully directional. An arc of five LEDs is used to show which direction the searcher should follow to the victim. Directional beacons use two, or more, antenna, the signal strength between the different antenna is compared by the computer in order to determine which way to turn. Impex wanted to improve on the range of the Tracker DTS. To do this the antenna are arranged in a T configuration in the case giving one long antenna for range and a shorter antenna for direction. We noticed that there was little difference in range whatever the orientation of the victims beacon. Impex claim 10% between best and worst case. The range is similar to the ARVA 9000 and around 75% that of the Ortovox F1.
Impex make the point that long ranges are not so useful with directional beacons as the search method they use involves following an oval flux line. With a long range this can lead the searcher on a long track, possibly over obstacles, better to pick up the signal closer to the victim with a more direct path.
ARVA Advanced in operation
When you switch the unit on it performs a self test and this is repeated every 5 minutes. Battery life is indicated on the display as a percentage. As with the 9000 the A.D.vanced can transmit for 250 hours without any decrease in signal strength. The searcher begins to criss-cross the search zone with the beacon pointed slightly downwards until the first signal is picked up. If multiple victims are within range this is indicated on the display. The searcher proceeds in the direction indicated by the direction LEDs with the approximate distance in meters to the victim decreasing. The loudspeaker also emits beeps the frequency of which corresponds to the range. When the searcher is within 3 meters of the victim the direction LEDs are switched off (center LED lit) and the searcher passes over the surface of the snow in a cross-pattern to obtain the lowest distance reading. This gives the approximate depth of burial although a probe should be used to localise the victim and confirm this distance. So far so easy and all worked as we would expect.
If there is more than one victim the searcher has a number of options. In standard mode the unit will automatically lock on to the strongest signal. The searcher can simply proceed with his search until the second (etc.) unit is located leaving other members of the search party (if available) to dig out the first victim. This risks missing closely buried victims. However by pressing the two large + and - buttons simultaneously for three seconds the A.D.vanced can be switched into analogue mode. The searcher will now hear the signals of all the beacons within range. If the ADvanced symbol on the display is flashing the - button must be pressed to reduce sensitivity. The display will then alternate the approximate distances to the victims, the higher figure will be the second victim. The approximate direction can be determined by sweeping the beacon through an arc to minimize this figure. The searcher should then proceed in the direction indicated and the lower figure should increase and the higher decrease. The signals from the various beacons is also heard through the loudspeaker. An earpiece or headphones can be used for greater sensitivity. Experienced users can tell the number and even type of transmitting beacons from the distinctive transmission signature. All of this is much harder than we have made it appear and it should be noted that professionals train at least once a week. The range in analogue mode is identical to digital (standard) mode. This was a disappointment as we had expected greater range as with the bi-mode Ortovox X1. Impex explained that in analogue mode the single, long antenna is used but the signal passes through the same electronics.
The beacon comes in the standard Impex ergonomic lozenge shaped case. It is slightly fatter than the 9000. It has undergone the usual shock testing. Switching from receive to search mode is via a large switch and all the controls can be used with gloves on. The harness also forms the switch which should ensure that the wearer cant set-off without the unit switched on. A magnetic switch is used which reduces mechanical wear and also means that the case can be waterproof. The unit is software upgradeable by the manufacturer using an external plug.
Date Tested: 15th January 2005
Update February 2006 The A.D.vanced has been improved for 2006 and handles the multiple victim problem by splitting the search area into 10 user selectable concentric search rings. The user can scan each ring looking for signals. Once a ring is selected the beacon will stay locked onto the beacon(s) that were found ignoring other signals. Current A.D.vanced owner can also get a software update from their distributor.
(:bc http://pistehors.com/ski-shop/gear/P-1_3_18_ATO0196/Snoop-Daddy-Alpine-Ski.html :) (:fw http://www.myreferer.com/cgi/?MERCHANT=facewest.co.uk&ID=pistehors&LINK=952612 :)
If you've tried the ARVA ADvanced write up your experiences here.
Manufacturer's website: http://www.nic-impex.com/