Many electronic devices can affect avalanche transceivers. And metal, even in food wrappers, can affect
a transmitting beacon. This page contains advice based on informal testing and the manufactures' instructions.
Read your user manual for specific advice.
When searching, your consumer electronics (e.g., phones, cameras, headlamps,
heated gloves, music players, etc)
need to be further away from your transceiver than when transmitting. (These devices haven't been shown
to interfere with a beacon's transmissions.) Here are some examples of official recommendations:
- The Tracker3 manual says at least 50cm (20 inches) when searching and at least one inch when transmitting.
- Most Ortovox manuals recommend at least 30 cm (12 inches) from other electronics. The
Ortovox 3+ owner's manual increased that to 50 cm
- ARVA and Mammut say electronic devices should be kept at least 50 cm (20 inches) from other electronics.
My testing leads me to feel that the recommendation of 50 cm (20 inches) when searching is
an appropriate minimum. And if you are on a phone call when someone is searching, the phone should be much
further away—ARVA suggests 25 meters.
To be even safer, turn your electronic devices off anytime you are searching (which is what most manufactures suggest). And
since this would be easy to overlook during the inevitable panic of a real rescue, it best to turn them off before
you enter avalanche terrain.
It is preferable to turn your electronics off when transmitting so you don't forget to turn
them off when searching. If you choose to keep your electronics turned on, keep them at least 20 cm (8
inches) from your avalanche transceiver. Although the actual distance where your
electronics will interfere with your transmitting beacon is less than 20 cm, you
don't want the items to get within a few inches, or touch, if you are tumbled in an
avalanche. For example, you wouldn't want your transceiver harness to shift in such
a manner that your transceiver is touching a radio in a chest harness.
Metal can partially block a beacon's transmission. In our testing, we discovered that something
as seemingly innocuous as a few Gu gel packs (which contain metal sandwiched in between plastic layers)
can drastically shorten a beacon's transmission range. Don't keep any suspected metallic layers in a clothing
pocket that might overlap your transceiver. Likewise, don't allow your cell phone, pocket knife, or two-way
radio to get within a few inches of your transceiver—even when transmitting.
- Remember that a cell phone that is not being used still transmits a signal to the cell
service periodically even when not placing a call. Even in "airplane" mode the power conversion
can cause interference. And as mentioned above, don't let your cell phone get within an inch or
two of your transceiver even if your cell phone is turned off—it's still metal.
- MP3 music players can wreak havoc during a search. I've seen a tiny no-name MP3 player
that was in the front pocket of a searcher confound his transceiver. And don't forget that GoPro
strapped to your chest. In our informal testing, 30 to 50cm (12 to 20 inches) seems necessary if
you want to "be a hero."
- In search mode, irregular readings and decreased range can also be caused by other sources
of electrical interference, such as power lines, lightning, and electrical generating equipment.
Ironically, chairlifts also generate background "noise" that can affect the searching
- The Petzl Tikka XP2 headlamp cautions, "Warning, when your lamp is lit and in
close proximity to an avalanche beacon in receive (find) mode, it can interfere with the operation
of the beacon. In case of interference (indicated by static noise from the beacon [you won't
hear static on a digital beacon]), move the beacon away from the lamp until the noise stops,
or switch off the lamp."
- Several transceiver manufactures mention that people with heart pacemakers should "follow the pacemaker
manufacture's recommendations" and suggest that people with pacemakers should wear transceivers
on the right side of their body.
Diamond's heated gloves warn, "Electronically heated gloves interfere with avalanche beacon
reception. Turn gloves off while searching. If you are buried with gloves turned on, the search
beacon will see interference when it is within a 1/2 meter radius of the gloves." Although
heated gloves aren't commonly used by backcountry skiers, they are becoming quite popular with snowmobilers.
Turning off your gloves is one more thing you'll need to remember should calamity strike.
- Magnets can be a culprit, too:
- Some transceivers use a magnetic switch (even though the switch might appear to be
mechanical). It is possible, although not easy, to switch between Off, Send, and Search with
an external magnet. The transceiver will return to its previous mode when the magnet is removed.
This is another reason to avoid jackets with magnetic closures.
- Some transceivers use a magnetic compass while searching (e.g.,
Mammut Pulse and Ortovox S1).
It is especially important that you keep magnetic items away from these transceivers while searching.
Be especially wary of magnetic closures on jackets.
- The Black Diamond Magnetron carabiners include a warning saying that the carabiners
should be kept 50cm (20 inches) from avalanche transceivers.