Interference with Avalanche Transceivers

Friday, 9 November 2012

I feel compelled to add this today as there has been a lot of publicity in the past few days about GoPro video cameras interfering with avalanche transceivers during searches. GoPro cameras have become very popular in recent years as a great way of skiers and boarders recording their days out, with many people having helmet-mounted and chest-mounted units.

GoPro cameras are electrical. As such, like every electrical device, they have an electromagnetic field. Some devices have stronger fields than others, but avalanche transceivers are quite sensitive and it does not take much to interfere with them.

Generally speaking the electromagnetic fields in portable electrical devices are quite weak, so do not affect transceivers from a distance. However at close range (notably less than 30cm) the effect can be quite pronounced. As I said this is not limited to GoPro. Mobile phones, GPS, radios and even iPods can interfere.

If devices are turned off there should be no chance of interference. However if devices are turned on, and close to the transceiver then there can be interference. If you want to try this at home simply set your transceiver to search and then move a device closer to it and watch the display. Quite often your transceiver will find a signal (when in fact there isnt one), and will then give a very erratic display as to where it thinks the victim is.

So, when in the back-country we recommend that you preferably have surplus electrical items turned off. If they have to be used, remember to turn them off if you have to subsequently carry out a search.

Please note that we have not yet seen evidence that everyday items (GPS, mobile phone etc) will affect a transceiver that is in send mode. We will be testing for this in the near future and will let you know the results.