New beacon time and electronic interference

[chris_the_wrench]

Time for me to get a new avalanche beacon. I'm leaning towards the Black Diamond Guide BT, I had one of the old Pieps with the recalled harness and I believe it's fairly similar operation. My closeup vision isn't getting any better, so Im hoping to go physically touch some other models to see if I can see them any better without my glasses. Anyone have a suggestion that's easier to read? The Mammut looks to have a larger screen, I haven't touched one of those yet.

Another question is, I've been reading alot about the newer beacons and also about interference from other electronic devices and causing issues with the beacons. Recently I've began to carry a Spot into the backcountry. Not for the rescue aspect, but I like being able to message my wife that Im ok. Im horrible about predicting how long a ski tour, hike, kayak or mtb ride is going to take. Now I can tell her I think 3 hours, and when 3 hours is up I have a preprogrammed message I can send her that says 'I'm ok, taking longer than planned. Check in within a hour'. She can also follow my little bread crumb trail. But now I'm abit freaked out this 'safety' gadget(the spot) is messing with my other 'safety' gadget(beacon) and then there is my gps watch. Overthinking it??

 

[James]

Just don’t get heated gloves.

Not sure I’d be getting a grudgingly recalled beacon like the Guide BT, but others can comment.

Some beacons talk now.

 

[chris_the_wrench]

Some beacons talk now.

That voice was very calming....

 

[Slim]

Avalanche Rescue and Transceivers

Independent reviews of avalanche transceivers (beacons) and detailed information about avalanche rescue.

beaconreviews.com

I have the basic Mammut beacon. I can check the font size for you. It varies for different things.
The arrow is fairly big, but the ikons for multiple burials are quite small.

I am with @James, not super excited to see that BD/Pieps was recalled again, and again, they weren’t exactly doing great on it.
As usual, @Analisa has a great explanation: https://femignarly.com/2022/04/16/black-diamonds-bungled-beacon-safety-messages/

The Diract voice seems like a great idea from a psycolological standpoint, since we react better to voice than visual when under stress. Farsightedness would be another reason for it.
On beacon reviews he does mention a short range, but that was a preproduction model, and not formally tested, so take that with a grain of salt.

 

[Slim]

Another question is, I've been reading alot about the newer beacons and also about interference from other electronic devices and causing issues with the beacons. Recently I've began to carry a Spot into the backcountry. But now I'm abit freaked out this 'safety' gadget(the spot) is messing with my other 'safety' gadget(beacon) and then there is my gps watch. Overthinking it??

I think it’s a valid concern.

https://arc.lib.montana.edu/snow-science/objects/ISSW14_paper_P4.13.pdf

The Avalanche Review mentioned there was a workshop held this fall about electro magnetic interference, with manufacturers, guiding associations and others, so hopefully in the future there will be better information out.

In the meantime here is what I do:

• Keep all electronics 30cm‘s from beacon on body. (Spot can go in backpack)
• wear my watch on my right hand when skiing (I am left handed, so hold my beacon there when searching)
• set Spot/Inreach to long intervals for checking its GPS location and for transmitting its location to the internet.
• Set phone to turn off screen quickly, and turn it off manually every time after using the phone

I am no electronics engineer, but my gut feeling suggests that the biggest issue is from the highest power electric devices, and devices that are broadcasting.

I am considering using shielding pouches for devices that don’t need to transmit (body of 2way radio, phone in airplane mode, camera), but will talk to my dad (who is an electronic engineer first).

 

[James]

A couple of the Diract videos mention false readings during testing in fields from likely phone gps. I can’t see how this is specific to any one model. Airplane mode won’t turn off gps, you have to do it separately. But then people want tracking too…

Heated gloves/mittens:

Electromagnetic Interference from Heated Gloves May Compromise Avalanche Transceiver Function - PubMed

Avalanche transceivers are susceptible to electromagnetic interference from gloves with electric heating elements. We do not recommend using heated gloves when performing a transceiver search for avalanche victims because it can lead to a delay in rescue.

pubmed.ncbi.nlm.nih.gov

——————-
Results: Preliminary tests showed that transmitting and receiving signals are degraded by electromagnetic interference caused by rectangular pulses emitted by activated heating elements.
Field tests revealed significantly reduced distances of first signal detection when heated gloves were turned on near receiving avalanche transceivers (P<0.001; Wilcoxon signed-rank test). Decreased distance to target beacon ranged between 1.9 m (5%) and 41.5 m (94%) at first detection, depending on the avalanche transceiver used.
—————-

 

[In2h2o]

So quick google refreshed my recollection - not just the phone but metal and other items and interesting how beacons are affected when in search mode. When I have been working with my favorite guide (who is also AIARE instructor) the in reach goes in the backpack / beacon carried on the front of body phones off and away from beacon.

Avalanche Canada

www.avalanche.ca

https://beaconreviews.com/interference.php

As another disappointed Pieps owner I have stoped using my 'recalled' beacon.

 

[Slim]

@In2h2o , yep Inreach in backpack is easy. But phone and camera I like to have accessible.

Turning the phone off is not very practical. I use my phone for navigation, (as a GPS unit with maps downloaded) , for slope angle measurements and as a camera.
I am guessing most people do the same, at least part of the time.

So while I put it in airplane mode to save battery, I know that doesn’t eliminate (all) interference.

I can’t edit my post above, but I meant that I turn my screen off manually after using my phone.

 

[Pequenita]

I don’t think you’re overthinking the electronic interference issue. I did a few practice searches a few years ago with a huge crowd, and the signals coming in to my transceiver were wildly variant because of how many cell phones and Apple Watches were in the mix. Later, when I did a solo search, everything was fine (so it wasn’t user error). I wouldn’t turn off the SPOT/Inreach, but I’d try to have it not right next to your transceiver.

 

[James]

It doesn't bode well for being buried with a phone on and gps going, plus a gps watch, plus whatever other electronics. Def good reason not to use heated gloves back country. Wonder if the heated socks matter.

At least searching you could turn the phone off.

 

[clewis]

I have the mammut barryvovx it's simple and straight forward to use.

Electrical interference is real and something to consider. Lots of good suggestions above to mitigate it.

 

[Slim]

It doesn't bode well for being buried with a phone on and gps going, plus a gps watch,

At least searching you could turn the phone off.

The problem I have with turning the phone off, is that it takes quite a while, and you have to watch it all that time, because if you let go to soon, it turns back on, you also need to remove gloves, and of course, you have to remember to do it.
So all in all, quite a pain.

 

[slow-line-fast]

I've been hearing minimise other electronics, and keep them at a distance from the transceiver.

So it seems an easy win to leave apple watches and gopros at home.

Things that make some sense are phones for navigation and possible emergency calls, as well as Spot or other PLB.

 

[James]

So it seems an easy win to leave apple watches and gopros at home.

Yes, but Garmins and the like are popular.
It sounds like the industry needs some hard data with all these devices.

 

[charlier]

We teach the 50/20 cm rule for avoiding EMI, keep your transceiver 20 cm on send mode and 50 cm for search mode.

EMI is most strongly a function of distance of the offending device from the transceiver - recently, all the manufactures have agreed on the "50/20 cm rule". FYI, the industry is studying EMI.

Power is the biggest driver of the amount of EMI. It doesn't make a difference if the phone is in airplane mode, it actually matters more whether the screen is on because lighting up the screen draws more power. EMI has the greatest impact in signal acquisition and coarse search. As you get close to the buried transceiver, the strength and volume of the single is easier to pick out of the noise.

Lastly, there is a lot of variability in the impact of EMI because all the devices are different. The end result to deal with EMI is always to reduce search strip width and since you don't know when EMI is in play, so we teach a 20 m search strip widths.

My last suggestion, the best transceiver is the one you use, practice with, and have read the manual. What else, avoid heated gloves, heated socks while on fine-search, reflective aluminum foil liners in jackets (e.g., Columbia), stow in-reach in pack/all dangles (if on pack strap, the device will probably be lost in an avalanche.

Edit from cmr, Two articles from Karl Klassen, Avalanche Canada. I added the original article, so everyone has access to both blogs.

Avalanche Canada

www.avalanche.ca

https://avalanche.ca/blogs/interference-part-2

 

[Slim]

Here is the article discussing @charlier ’s points:

“ an interesting result is that the interference produced by an iPhone was similar when airplane mode was enabled and disabled. In both cases, the display was on. “

Avalanche Transceiver Interference Sources with Search and Rescue Considerations | Backcountry Access

For years we've been aware that electronic devices, metallic objects, and even foil energy bar wrappers, may interfere with an avalanche transceiver search. Despite this, many users areundefined

backcountryaccess.com

 

[slow-line-fast]

Link in @charlier 's post should be:

Avalanche Canada

avalanche.ca

@mods, can we pin a post? This from @charlier is definitive

We teach the 50/20 cm rule for avoiding EMI, keep your transceiver 20 cm on send mode and 50 cm for search mode.

EMI is most strongly a function of distance of the offending device from the transceiver - recently, all the manufactures have agreed on the "50/20 cm rule". FYI, the industry is studying EMI.

Power is the biggest driver of the amount of EMI. It doesn't make a difference if the phone is in airplane mode, it actually matters more whether the screen is on because lighting up the screen draws more power. EMI has the greatest impact in signal acquisition and coarse search. As you get close to the buried transceiver, the strength and volume of the single is easier to pick out of the noise.

Lastly, there is a lot of variability in the impact of EMI because all the devices are different. The end result to deal with EMI is always to reduce search strip width and since you don't know when EMI is in play, so we teach a 20 m search strip widths.

My last suggestion, the best transceiver is the one you use, practice with, and have read the manual. What else, avoid heated gloves, heated socks while on fine-search, reflective aluminum foil liners in jackets (e.g., Columbia), stow in-reach in pack/all dangles (if on pack strap, the device will probably be lost in an avalanche.

A follow-up article from Karl Klassen, Avalanche Canada - discusses airbag, snow machines, et al. Let me know if anyone has not looked at interference-part-1 and I can easily post the link.

https://avalanche.ca/blogs/interference-part-2

 

[charlier]

@Slim - most of these issues are currently under review - passive and active interference.
FYI, I use airplane mode, mostly to save iPhone battery using GPS mapping apps.

 

[slow-line-fast]

Here is the article discussing @charlier ’s points:

“ an interesting result is that the interference produced by an iPhone was similar when airplane mode was enabled and disabled. In both cases, the display was on. “

Avalanche Transceiver Interference Sources with Search and Rescue Considerations | Backcountry Access

For years we've been aware that electronic devices, metallic objects, and even foil energy bar wrappers, may interfere with an avalanche transceiver search. Despite this, many users areundefined

backcountryaccess.com

A carefully conducted test and writeup, but I wonder: in what situation would one have an active phone display and be involved in a search? All I can imagine is someone with mobile coverage trying to alert rescue either through an app or emergency call, while also searching. And in that case, if there are other searchers, their devices would be more reliable.

 

[charlier]

A carefully conducted test and writeup, but I wonder: in what situation would one have an active phone display and be involved in a search? All I can imagine is someone with mobile coverage trying to alert rescue either through an app or emergency call, while also searching. And in that case, if there are other searchers, their devices would be more reliable.

We suggest, with the worst case scenario as a single person companion rescue. Call 911 and alert them to a single burial. Tell them you will get back with an update. Stow your phone 50 cm away (or turn it off) and start your search. Update 911 after you have a successful recovery. SAR will be psyched that they do not have to assist. With another rescuer or two, one will probe and everyone will shovel. SAR/911 will get an update after you finish shoveling. Let’s have a later discussion, if you cannot reach 911.