Do Cell Phones Interfere With Avalanche Beacons?

YES. Portable electronics like phones, radios, GPS, cameras, etc. will interfere with an avalanche beacon (aka avalanche transceiver). Is it a problem? The interference is significant and may prevent you from finding a buried partner. These electronic devices typically need to be turned on to cause interference. Snowmobiles with running motors and electrical circuits will also cause interference.

Most solid, non-electrical, objects will not cause interference. These objects include snow, trees, rocks, clothing, skis, etc. Another common object is a RECCO reflector which is often built into jackets, and this object will not cause interference.

Studies have shown there is little interference with a transmitting beacon. If you’re buried and you forgot to turn off your iPhone, don’t worry. Just to be safe keep your iPhone or other device about 8 inches away from your beacon. Interference mostly occurs when beacons are in search mode.

BarkhausenGraph

“The x-axis represents the various beacons at distances of 0, 10, 20, 30, and 40 cm from the electrical device. The y-axis is the “Theta” value, which is the difference between that beacon’s normal effective receive range and the effective range it got with the electrical device 0, 10, 20, 30, and 40 cm away. If the colored lines are low on the y-axis, that means that transceiver is less susceptible to noise than the beacons on either side of it on the x-axis. So the Tracker DTS is the least susceptible to noise and the Pieps DSP is the most susceptible.

You’ll also notice that the iPod (orange line) and the GPS (red line) are the biggest culprits in creating interference, which is consistent with our experience.” – backcountryaccess.com

Recommendations:
– Turn off all electronics and put them in your backpack.
– If you need to keep a phone or radio on your body, keep it 8 inches from your beacon. Keep the phone in “airplane mode” if possible
– If conducting a search and you suspect interference, simply extend your arm to get your beacon about 1.5 feet away from any electronic devices.

By: Todd Eberts, Back Country Free Ride Avalanche Instructor