Avalanche Beacon Check

Each year before the season starts I grab all of my beacons, insert a fresh set of batteries in each beacon and head to a nearby park. At the park I want to reactivate the avalanche rescue skills that I haven’t used for several months and confirm that my beacons are all transmitting and receiving properly before I head out for my first tour of the season.

It’s important to remove the batteries from your beacons at the end of the season to prevent corrosion damage. Backcountry Access (BCA) supplies the Tracker3® beacons used by CMS guides and available for use by students in AIARE courses. BCA recommends not using the batteries taken out of your beacons last Spring in an avalanche beacon again. Once a battery has started to discharge, changes in the battery’s chemistry will continue even when the battery is removed. Your beacon’s transmit power depends on reliable batteries; start the season with a fresh set.

AIARE Level 1 student practices beason search skills.
Colorado Mountain School student practices beacon search skills on an AIARE Level 1 course.

A good beacon testing location should be far from sources of electrical interference. I tried doing beacon tests in my backyard and found that interference from a street light about 60 meters away was playing havoc with my searches. The ideal location will be at least 150 meters from any possible source of electrical noise: power lines, machinery, antennas or metal structures. The trailhead check that we perform before each tour checks battery power, transmit and receive functions. It isn’t intended to test a beacon’s ability to transmit and receive at a proper distance.

To do a range check I place one beacon to be tested at least 150 meters away and then approach slowly with my second beacon in search mode. Note how far away the searching beacon picks up a signal lock from the transmitting unit. If the distance is less than 45 meters then there is a problem with either the power of the transmitting beacon or the sensitivity of the receiving beacon. You would need a third beacon in known good condition to isolate the problem. You may want to run this part twice with the transmitting beacon rotated 90-degrees to observe the difference that the antenna position makes in observed range.

Note, if you start close to the transmitting beacon and walk away you will usually get a much greater range. Once the searching beacon has locked onto a transmitted signal it will maintain that lock to a greater distance than the distance where it can acquire a new signal.

If both beacons pass the first step of the test swap the transmitting and searching beacons and repeat the test. Once all my beacons are confirmed in good condition I’ll only do another distance check once or twice a season or anytime I have reason to suspect that that a beacon may have gotten damaged.

If your beacon is a two-antenna model it’s probably time to start thinking of an upgrade. The old beacon will make a great burial unit for search practice.

Beginning with the 2017-2018 season AIARE has introduced a new one day Avalanche Rescue course which focuses on companion rescue skills exclusively. It’s a great way to refresh and improve the skills you learned in a Level-1 course or prepare for Level-2.

Thomas White