phones and other electronic devices can interfere with avalanche
transceivers. This page contains advice based on informal
testing and the manufactures' instructions. Be sure to read
your user manual and to contact the manufacture
of your transceiver for specific advice.
Electronic devices (cell phones, radios, headlamps,
heated gloves, MP3 players,
GPSs, etc.) can affect avalanche transceivers. The electronic
devices primarily affect the searching beacon and not the transmitting
beacon. (I've seen a tiny no-name MP3 player that was in the
front pocket of a searcher baffle his transceiver.)
The Petzl Tikka XP2 headlamp contains a warning stating,
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."
Diamond's heated gloves have a warning stating, "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."
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 transceiver.
It is preferable to turn off your electronics when transmitting
so you don't forget to turn them off when searching. (Consumer
electronic devices haven't been shown to interfere with a beacon's
transmissions.) If it is not practical to turn them off, always
keep them at least several inches away from your transmitting
beacon. Metal objects should also be kept away from your transmitting
beacon (e.g., pocket knifes, additional transceivers, etc).
When searching, the electronics and metal objects
should be further away from your transceiver than when transmitting.
The Tracker DTS manual says at least 15 cm (6 inches),
The Tracker2 manual says at least 30 cm (12 inches). In
early-2014 BCA told me they're now recommending 30 cm
when transmitting and to turn off all devices when
searching. They said that some devices (including some
phones) create so much interference that they should
never be turned on when searching.
Ortovox has always said to keep their transceivers at
least 30 cm (12 inches) from other devices. The
Ortovox 3+ owner's
manual says 50 cm (20 inches).
Mammut says at least 50 cm (20 inches).
My informal testing leads me to feel that the Tracker2
and Ortovox recommendations of 30 cm (12 inches) is a reasonable
minimum. Of course, it is best if you turn the devices off
(which is what most manufactures suggest), but turning off
radios and cell phones during a rescue may not be realistic.
Remember that a cell phone that is not being used still transmits
a signal to the cell service periodically (I have been told
that this occurs every 3 to 15 minutes).
Some transceivers use a magnetic compass while searching
It is especially important that you keep magnetic items away
from these transceivers while searching. Be especially wary
of magnetic closures on jackets.
Some transceivers use a magnetic switch. 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.