Most 3 antenna beacons have a critical distance (as far as at what point electromagnetic interference becomes a real problem) of something in the range of 3 cm. Typically, devices outside of that range won’t play much of a role at all, particularly in SEND.
Most manufacturers though recommend keeping a phone at least 20 cm from a transceiver in SEND, and 50 cm in SEARCH, for a lot of reasons, but primarily because of the tendency for items to violently shift in an avalanche (I’m talking about the 20cm in send mode when stowed on your person). There is some limited evidence that when using a beacon in SEARCH, a phone closer than 50 cm can do some wonky things, though.
Transceivers and interference can be pretty unpredictable at times, and weird stuff definitely happens, so I’ll give you that. That said, personally as someone that has trained and experimented extensively with transceivers, RECCO and even purposely trying to create interference with electronic devices and metal, I’ve yet to encounter a cell phone actively making locating a transceiver impossible or even difficult—on or off. RECCO on the other hand is sensitive as hell when it comes to interference. I genuinely wonder if some of the cellphone stuff is liability related. Even talking to Manuel personally and the designer of the mammut fleet of transceivers makes me think having a powered on phone isn’t the fatal error I’ve seen it characterized as.
I wholeheartedly agree with your points about the backpack (this is totally egregious...that back pack has a very high likelihood of being ripped from your person in a slide....potentially creating a situation where a companion rescuer mistakenly dogs up your
god damn pack, as your packless body dies and your friend properly wearing a beacon does too....dumb as fuck!), the exposing of the whole group to the run out of an obvious frequent avalanche path in high danger conditions, the underestimating of the ability to remote trigger persistent slab avalanches in conditions that exist right now, etc.
These events are truly tragic, and I can see how picking them apart immediately can seem callous. However, I also think it’s incredibly important for people in this community to openly and honestly discuss others’ mistakes to reaffirm to themselves what to do/not do. The truth here is that in each of these incidents, major errors were made. That’s not to say that I/we couldn’t make the same ones tomorrow, or that these people were fundamentally careless or anything like that. Smart, diligent people make mistakes,
and snow covered mountains are a damn dynamic and scary environment.
hemlockjibber8Glad to hear your buddies are ok but please don't mention a remote trigger and act as if it was out of their control. You should be considering what would remote trigger onto you 100% of the time you are out in the back country.
Considering your friend was well educated, I’m curious what led them to that situation. Hanging out in a slide path during high danger conditions, having everyone in the same exposed zone at once, not doing a transceiver check at the trail head and then keeping it where it belongs, using his phone (that shot should be off), continuing to film as people are buried. If I saw goons like this where I was skiing I would have told them to go the fuck back to the city to be honest.
**This post was edited on Feb 8th 2021 at 11:06:01pm 
