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qwert
Feb 28, 2013, 2:43 PM
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Registered: Mar 24, 2004
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Does anyone know if there is any work done on investigating the interferences caused (or not?) by cellphones?
The guide that came with my beacon (and i assume its roughly the same with other manufacturers) just says that i should avoid placing sources of interference (such as mobile phones, headlamps, other beacons) next to it, with no definition of next, and no close explanation about why.
Also I doubt that anyone really follows this advice. If its dark I need a headlamp, and the mobile phone is a standard part of my safety equipment. As a short test, I placed my phone on a beacon that was sending, while the phone was streaming youtube, and i didnt have any problems finding it with another beacon.
On the other hand, I had one beacon constantly finding "something" far outside my testfield, and I never found out what it was, because the distance and direction always changed. Maybe that was phone interference or the nearby powerline?
So essentially I now have two observations, one saying phones dont matter, and one saying they might matter. That is a bit thin to draw any sensible conclusion, so I'd like to ask if anyone knows about some other tests on the subject.
qwert
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jp_sucks
Feb 28, 2013, 4:49 PM
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Registered: Oct 31, 2006
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Cell phones are fine to use near beacons, no real issues there. The manufacturers will say that it "might cause issues" just to help cover their butts.
However, cell phones and other electronics WILL throw off other avalanche search equipment such as the RECCO system.
If you want a more detailed answer, send an email to the Canadian Avalanche Association: info@avalanche.ca
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jmeizis
Feb 28, 2013, 6:37 PM
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Registered: Apr 25, 2006
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Here's a BCA blog post on the subject that suggests they can.
http://www.backcountryaccess.com/...trical-interference/
I've also heard the 40cm thing several times from various people. It sounds like you mitigate that risk by holding it an arm lenth away from other electronic devices.
I've not personally had a problem with electronic devices but usually they're outside of that 40cm range. My beacon is on my chest while the electronics are usually in the top of my pack.
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qwert
Mar 1, 2013, 9:50 AM
Post #4 of 5
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Registered: Mar 24, 2004
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Thanks, that is what i am looking for.
Quite interesting that it only seems to affect the receiving beacon, and not the sender. But at least there is no need to call a burried person and tell her that he has to remove his cellphone from the chest pocket in order to be found.
However two things i do not really understand:
The ipod. What ipod is it (classic, with a spinning HDD, touch with running WLAN, nano with nothing?) and what state is it in (playing music, searching WLAN, standby/off), and how come that the device that is not really a sender or receiver seems to produce the most interference?
The 40cm rule. So that means as long as i hold the receiving beacon at arms length (which seems like the standard position anyways) I wont have problems? Again, what state were the electronics in, in order to get to that value? A cellphone should produce vastly different radiotions when it is just booked into the net at good reception, versus the cellphone running on full power sending or receiving something in an area with bad coverage.
qwert
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majid_sabet
Mar 1, 2013, 6:56 PM
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Registered: Dec 13, 2002
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I work in the state of the art electronic lab and cells are operating at 900mhz or higher freq while beacons are running on mid 400mhz so there is big gap in frequency range however, as the law of electronics goes, once things are in the air, you never know specially in the radio and transmission world.
If devices are too close to each other, its possible things go side way. clocks .isolators,non-shielded chips and boards could effect one another but most electronic manufactures test these trans-receivers in variety of conditions to make sure they do not interference with other devices. I'll say, turn the phone off next to avi beacons or even a frs radio. for example, if you use wally-talky radio next to other electronic devices, during transmission, you could fry other receivers and I seen that very often with high power ham radio.
speaking on Avi beacons, I got 10-14 different models I use when teaching classes and I like to know what most people use and recommend.
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