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The PisteHors team have used the ARVA 9000 and its later model the ARVA Evolution for over four years. It is the transceiver we give to inexperienced users as it is probably the most straightforward interface of any transceiver. We've even handed it to a five year old and told them to go find (we had to bury a bar of chocolate for motivation though. However there are some foibles which can could cause problems during the stress of a real live search.
The unit is either a yellow (old design) or orange (new design) bullet shaped box measuring 135 x 80 x 25mm and weighing 220 grams. There is a 5 year guarantee and the units can be returned to the importer or manufacturer for services and repair. Given that the frequency of the crystal oscillators can drift this should really be done every five years.
The harness consists of a webbed shoulder strap and an elasticated waist belt. The device sits at midriff level under the user's shoulder. This keeps it out of the way and protects it if the wearer should fall. One of our units fell 300 meters on an ice covered slope while being worn with no damage. The unit is shock proof. Nic-Impex manufacturer under ISO9002 standards and the device also complies with the European standard EN 300 718.
The unit is switched on by inserting a clip on the shoulder strap into the base of the unit. As the beacon is waterproof the switch consists of a magnet on the clip which actuates a switched housed in the body of the transceiver. We have heard of very occasional problems with this switch but it is probably at least as reliable as a mechanical switch.
When the unit is first switched on it performs a power-on self-test (POST) and a battery check. More recent units perform a self-test every two minutes. Users should also test the transmit and search function of their transceiver before setting off on a tour. The battery life is displayed as a percentage in the central LCD display. The digital circuitry of the device requires a six volt supply delivered by four AAA cells. These give a battery life of around 250 hours. Enough to last the average backcountry user a whole season. The manufacturer claims that there is no drop off in power during the useful battery life. We found that the ARVA 9000 had the longest battery life of all the digital units we have tested. With the unit in transmit mode the central direction arrow flashes about once a second. The arrow is illuminated by two high powered red light emitting diodes (LEDS). These were visible even in bright sunlight.
The unit can be switched to search mode using a large red switch located on the nose of the unit. This can be easily operated with gloves on. If there is a second avalanche this switch must be pressed to return to transmit mode which is a simple and quick operation. There is no automatic return to transmit mode on the unit. The ARVA 9000 is a single antenna unit with digital signal processing and display. The user navigates to the avalanche victim using a range indicator and a direction arrow. The normal search operation is by following the flux line transmission of the victim's unit although the range indicator can be used to perform a cross search.
In search mode and out of range of another avalanche beacon the central red LED will flash periodically to show that the device is working. The range to first signal is around half that of an analog Ortovox F1 and similar to the two antenna Tracker DTS and Barryvox Opto 3000. The unit we tested was very sensitive to electromagnetic interference, especially mobile phones, radio transceivers and power lines. It could even pick up a Suunto altimeter watch in close proximity. All such devices should be switched off or used away from the search area.
When the user comes in range of the victim's beacon the central display will show the distance to the victim and the unit will begin to emit a series of beeps. The display equates roughly to the number of meters although the accuracy depends on the depth of burial, battery condition of the transmitter and orientation of the antenna, in short on the transmitter's signal strength. We found that first signal is detected at around 45 meters in good conditions. The range indicator is inaccurate at this distance and the figures can fluctuate substantially. This could prove disturbing for an inexperience user. The user should continue in the same direction all the time keeping the unit in the same orientation while sweeping in a 60 degree arc from left to right. As the searcher approaches the victim the frequency of beeps increases.
Within about 10 meters the direction arrow will light when the unit is roughly aligned with the flux lines from the victim's transceiver. Although not as precise as a two antenna unit this proved sufficient to localise a transceiver buried under 50 cm of snow. The user has to slowly sweep the unit in an arc from left to right in order to localise the flux line rather than being guided by an arc of arrows as with the Barryvox Opto 3000 and Tracker DTS. Within about 2 meters the direction information is turned off, the LEDS are lit constantly and the unit beeps much more frequently. At this range the flux lines are so sharp and closely packed that direction information is of little use. This surfeit of information also means that the searcher must slow down as he approaches the victim, not always easy in the panic of a real search. The user should now perform a final cross search, using the range display, to localise the victim before probing.
proved more difficult with this unit, the processor is not particularly fast (although processing speed of the Arva Evolution is improved) and the searcher needs to proceed quite slowly over the final search area, keeping the unit in the same orientation. In our test we found two minima (using the range display) and spent more time than necessary searching with the beacon when we should have moved to a probe search in a spiral pattern from our maxima.
The Arva Evolution will indicate if there are multiple victims although when searching for members of the same party this should be obvious. The beacon locks onto the strongest signal. To find subsequent victims the searcher should continue traversing the avalanche site with the unit oriented away from the flux line of the first victim. As the user moves away from the first victim the range indicator will increase. When the unit locks onto a new, stronger signal there is a clear switch and the searcher then proceeds as before. We tested the unit searching for two transceivers and didn't have any problems in this scenario although it may be possible to miss a second victim located close to the first.
The ARVA 9000 is an easy to use pure digital avalanche beacon. It is well built and has a good battery life. We felt the main weak points were the inaccurate and fluctuating range display which could be confusing, the processing speed of the unit and its sensitivity to extraneous electromagnetic interference. In a real situation a searcher would have to keep a cool head.
The user interface was very simple and easy to understand and operate. The LEDs were bright even in sunlight. It was straightforward to find a second victim with this unit.
Further Information Manufacturer's website: http://www.nic-impex.com/
Dates Tested: 16th August 2000, 15th March 2004