avalanche transceivers and mobile phones

Avalanche transceivers are probably the most important bit of extra equipment you should be carrying if you are skiing off piste. They are devices designed to help find people buried by an avalanche.

They work by continuously emitting a radio signal on a standard international frequency (457KHZ). If someone is buried, they can be located using the search function on another transceiver. All transceivers require training and practice to use properly, with some being easier to use than others.

Switch it off
In our busy skiing world a lot of us carry mobile phones. Some to stay in contact with friends, others for work or just for emergency use. Carrying a mobile whilst off piste may seam like a great idea safety wise for calling for help…..BUT if it is switched on it will interfere with your avalanche transceiver. With analogue transceivers (harder to use) it makes the system slower and less efficient, but with digital transceivers (easier to use) it stops them working altogether.

To be safe you should carry your mobile, but switched off!  If you need to keep in touch or for work, just stop periodically, switch it on and check messages, then switch off again. There have unfortunately been a few recorded incidents this year and last of people dieing in avalanches because they could not be found quickly due to mobile phones causing interference.

Tried and tested
I have tried testing this interference problem myself with a simple experiment. Whilst practicing searching for transceivers I placed a mobile switched on next to the one I was searching for. In also tried carrying a phone while searching on occasionally getting the phone to ring or sending text….

The result was quite scary, I could find transceivers with a phone next to them, but slowly and only with my Otravox and Peips (Analogue), using an Arava 9000 and Baryvox (digital) I couldn’t find anything. If I carried a phone switched on but not ringing I could not find anything regardless of which type of transceiver. Ringing the phone or texting just sent everything haywire!

When skiing the valley blanche the Guides have taken to checking that their clients switch their phone off before starting. Be safe and switch those annoying things off!

By Tom Greenall (BEng Electronic and Electrical Engineering & Natives Senior Reporter)