UIAA position on avalanche transceivers interference from electronics or other device

[sfotex]

Another scary and sad story about beacon interreference and snowmobiles:

https://utahavalanchecenter.org/avalanche/77884

[sfotex]

The theme this year at the International Commission on Alpine Rescue Avy was beacon interference, I posted my report over here:
https://www.tetongravity.com/forums/...mission-report

I was too lazy to re-edit to post in here.

[sfotex]

One thing to remember is this recommendation has to deal with ALL beacons in service and the possibility of whatever cheap knockoff Alibaba bluetooth controlled heated gloves someone might buy.
If your really concerned its easy enough to test your stuff.
I mean, do you really want to take off your gloves vs. turn them off if your doing a real rescue?

[LeeLau]

Just tested Barryvox S on receive. Out of curiosity also tested our older Barryvox Element on receive. Target beacon was another Barryvox S.

- Radio on receive and transmit to 0.1m. No result
- Headlamp to 0.1m. No result
- Garmin watch recording. Resulted in multiple burial signal at 0.2m (ie ghost signal) Turned off the target beacon and searched the watch. Nil result to 0.1m
- Samsung G20 phone airplane mode on and off. Nil result to 0.1m

[sfotex]

Just tested Barryvox S on receive. Out of curiosity also tested our older Barryvox Element on receive. Target beacon was another Barryvox S.

- Radio on receive and transmit to 0.1m. No result
- Headlamp to 0.1m. No result
- Garmin watch recording. Resulted in multiple burial signal at 0.2m (ie ghost signal) Turned off the target beacon and searched the watch. Nil result to 0.1m
- Samsung G20 phone airplane mode on and off. Nil result to 0.1m

How far away was your target beacon?

[LeeLau]

How far away was your target beacon?

I stuck the target at a 20, 30 and 40m distance

Edit. Any suggestions for getting better / more representative results? I haven't tried with an Inreach yet. Or a GoPro (as I don't have one).

[suncrustable]

Other interesting thing to check might be individually foil wrapped foods, both the barfood and snack food I tour with sometime are packaged in foil.

BCA had a presentation on this at NSAW this year where they did similar tests, but they didn't publish the beacon models.

[sfotex]

I stuck the target at a 20, 30 and 40m distance

Edit. Any suggestions for getting better / more representative results? I haven't tried with an Inreach yet. Or a GoPro (as I don't have one).

So with active interference in search mode there's typically two types of problems you will see.
1) Your effective search strip size will be reduced, so try it right around when you get a signal
2) Ghost signals. Try it with when you don't have a search signal.

I don't own any heated gloves, but I 'made my own' with a USB power pack (another noisy thing) and a wireless phone charger pad. Inreach isn't to bad. Electric airbags can be noisy too.

[LeeLau]

Thanks sfotex! Just didn't want to have a false sense of security.

Per your suggestions. Target beacon Mammut Element; receiving beacon Mammut Barryvox S.

Max range received ~ 49- 54m

Cycled power on/off/on
- Radio (5W Baofeng - stock antennae - receive & transmit) - nil result to 0.1m
- Samsung G20 phone - ghosting (two signals detected intermittently at 0.1m) but no range degradation
- Garmin GPS watch - ghosting (two signals detected intermittently at 0.1m) but no range degradation
- BD headlamp - nil result

Flipped the test. Target beacon Mammut Barryvox S.; receiving beacon Mammut Element

Max range received ~ 45- 47m

Cycled power on/off/on
- Radio (5W Baofeng - stock antennae - receive & transmit) - nil result to 0.1m
- Samsung G20 phone - ghosting (two signals detected intermittently at 0.1m) but no range degradation
- Garmin GPS watch - ghosting (two signals detected intermittently at 0.2m) but no range degradation
- BD headlamp - nil result

[sfotex]

^^ Some other variations to try if your not bored yet is screen/on off with your cell phone, your headlamp at different brightnesses, and interference caused caused by 2 beacons close to each other.

[Pinner]

Lots of pants pocket users here. Note of caution to newbies reading this-- your pocket MUST have a secure lanyard attachment if you choose to do this.

Ideal set up is of course a chest harness. Best practice for pant pockets is a piece of spectra or other durable cordage looped around a leather or other stout belt.

If you take a ride, you're gonna want that sucker attached to your body, not your clothes.

[wstdeep]

More than ten years ago I was educating a friend on searching with a beacon. He had heated gloves on and it rendered his beacon useless in search mode.

I put a "radio off" reminder tag on the front face of my beacon as a reminder to switch off if going into search...don't want to forget in the heat of battle.

[John_B]

Lots of pants pocket users here. Note of caution to newbies reading this-- your pocket MUST have a secure lanyard attachment if you choose to do this.

Ideal set up is of course a chest harness. Best practice for pant pockets is a piece of spectra or other durable cordage looped around a leather or other stout belt.

If you take a ride, you're gonna want that sucker attached to your body, not your clothes.

It's a good practice to have a spot to clip it in, but take a look at how janky the lanyards are that ship with your beacon before dorking out too much on a spectra attachment point. The lanyard that comes with a Barryvox would likely break at about 5 pounds of force and the attachment point on the beacon at not too much more.

[Pinner]

Heh. That's a good point.

Which, I guess, furthers the argument for chest harnesses.

[goldenboy]

BD with a great page on electronic interference: https://www.blackdiamondequipment.co...-interference/

[LeeLau]

BD with a great page on electronic interference: https://www.blackdiamondequipment.co...-interference/

Wow. Thanks for that F!!! From the article

"Using this principle, the “20/50 rule” was born. We can mitigate noise by keeping EMI sources a sufficient distance away from the transceiver. The 20/50 rule was adopted across the industry to help users remember to keep electronics and other sources of interference at least 20cm (8in) away from a sending transceiver and 50cm (20in) away from a searching transceiver. If you are only going to remember one thing, and make sure your partners know it too, it should be the 20/50 rule!"

Look at the interference from heated gloves! 90% signal degradation! Also substantial interference from a sled close to you or a smart or GPS watch on your transceiver hand

[bodywhomper]

Pretty helpful article.

Can/should we assume that all battery heated clothing (gloves, socks/insoles, vests) are similar?

The reduction from control table doesn’t show if/how the 20/50 rule changed outcome, or am I missing something or not reading close enough. Curious about radios, too. My understanding is that not all radios are equal, at least in terms of signal range, processing, etc.

[LeeLau]

Pretty helpful article.

Can/should we assume that all battery heated clothing (gloves, socks/insoles, vests) are similar?

The reduction from control table doesn’t show if/how the 20/50 rule changed outcome, or am I missing something or not reading close enough. Curious about radios, too. My understanding is that not all radios are equal, at least in terms of signal range, processing, etc.

I think you may have to do your own tests to get to that level

Re radios. Some are better for signal leakage than others so your understanding is correct

Re reduction from control table. They didn't follow 20/50 strictly but just indicated the typical use case. Eg GPS watch in transceiver hand vs on non-transceiver hand. Snowmobile at 0m, 20m etc

[bodywhomper]

Yeah. It should be interesting. Hopefully will get a chance to play more with some devices. I’ll share if I get info. The reduction %’s with your phone in pockets was surprising.

[LeeLau]

Yeah. It should be interesting. Hopefully will get a chance to play more with some devices. I’ll share if I get info. The reduction %’s with your phone in pockets was surprising.

Note they didn't specific if smartphone was on airplane or if bluetooth was off or what type of smartphone. See the personal "testing" i did with the guidance of sfotex using personal devices.

[bodywhomper]

Yeah. I saw that in your own data, and I appreciate the augmented data collection being shared in this thread. I realize that the report from BD is not exhaustive or entirely clear.

Fwiw, I tour with my phone in airplane mode, using it as a camera. Personally, need to keep it in a good pocket compared to transmitting transceiver and do the same for my partners. There’s often no cellular service in many areas that I tour.

Very different practice at the ski hill. Phone gets frequent use to comm with kids, friends, and spouse. Curious to try harnessed radio and transceiver in chest harness. Because of the recent incident, I predict more and more people will beeping at the ski hills. It’s pretty unclear how manufacturers will be sharing this nuanced information to their increasing customer base.