Transceivers - anyone carry them on piste/in bounds

A snowHead

Caspar, I can only speak from personal experience but if you want to find someone quickly then the "Tracker" digital type is very good for relatively inexperienced users. If you want to be the one found then type probably does not make much difference Puzzled

A snowHead

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Caspar,

The new Tracker is very easy to understand and use. I use an Ortovox M2 which is well regarded.
St A should have some in the shops but lesser resorts - as regards off-piste - may not have then in stock.
I didn't see any in La Plagne last week...!!

And if you are off-piste your companions should have one. You should all be carrying shovels and probe and be confident you know what to do with them. Try burying one in the snow and see how easy you can find it...!!

As I said in another post, I face-planted in the new snow last week just next to a drag lift and got covered in the fresh snow. I had to bash my head twice to get it clear of the snow and then spit out the snow in my mouth. That was a an eye-opener to the problems a big dump can cause right in the middle of the resort.
So if you are going near deep snow you should be prepared

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Thanks for the input guys. Before anyone says it, I also intend doing an avalanche awareness course.

Then you can post your own questions or snow reports...

Whilst skiing on piste, if I spotted an untracked bit of off piste that I could get to, I very much doubt that I would remember that I was not wearing my transiver. So for the cost of 2 sets of batteries per season I wear mine at all times. Shovel & probe are carried most of the time.

After all it is free

Dave J,

My girlfriends parents kindly bought the family transceivers for Xmas as we do occasionally venture off piste. Yes we are (mostly, and the exception is being corrected) carrying shovels and probes. We generally carry them on piste unless we are totally sure we won't go off piste because of location/conditions/warnings/etc.

Two things though.

1. we have practised using them, and will continue to do so. I have to say that it's not the easiest thing in the world to use them and it's very very scary how hard it can be to dig a rucsac out of snow once you've buried it deeply.

2. We now really carefully double consider our go/no-go decisions because carrying the kit does instill a "I'm kitted up so I'm safe" internal attitude. Which is COMPLETELY WRONG!!! Most irrational, but there you go.

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Caspar, It's been done to death here and elsewhere. But...Transcievers, shovels and probes will not make you safe. Staying out of avalanches makes you safe !

If you have not done so already, book a course in off piste and mountain safety........spend your money there, get experience, and then get the gear......

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ski,
Thanks - I fully intend to stay out of avalanches. As I said further up - I also intend doing an avalanche awareness course. No harm in getting the gear at the same time though.

Caspar, ooops - sorry, having a bad day. Just needed to get that off my chest ! Blush

You know it makes sense.

RECCO's latest newsletter Oct 05 contains a sobering report from the Swiss Alpine Club, that 75% of fatal avalanche accidents in Switzerland occur when the danger is rated at 2 or 3, they say that 30% are at 2 (moderate risk) and 45% when 3 (considerable).

The same report also says that to excavate a body 1m down in the avalanche debris, 4 cubic meters of very compact snow must be removed. This is approx 1.5 to 2 tons!

On the subject of RECCO I've spent time this winter with the Recco rep for the West Coast, Canada, they are now giving the receivers to ski areas and many manufacturers such as the North Face, Schoefel, Arc'teryx are building the reflectors into their clothes, and Atomic have them in all their Adult boots.

There was once an argument that Recco was just a body finder... No more! With cell phones and now satelite phones, in Switzerland (using the same article from the SAC as an example) 80% of mountain accident callouts are by cell phone, and the average time from call to REGA ( the rescue service) arriving is only 22 minutes (they quote 2003 for this, I suspect it is even better now!)

The latest RECCO receiver is no longer big and bulky, it is easy to carry, I used one this week. They are working on one now that also picks up the signal from a transciever too.

So yes, get a transceiver and practice with it, but pop a pair of Recco stickers (12 pounds in the uk for the pair) on your boots too!

And, finally, if you are skiing with your transciever on send, TURN YOUR CELL PHONE OFF!! Our ongoing experience is that a turned on cell phone really fouls up the ability to locate a nearby transciever.

Otherwise you'll just go on seeing the one name:

colinmcc, I'd be interested to know how a turned on cell phone influences an avalanche transceiver. Unless you are actively engaged in an conversation a cell phone is an almost completely passive device which does not transmit anything at all ( except an location update lasting about 1/2 second once every thirty minutes or so ). It doesn't even have a high frequency clock running most of the time, but only switches the 13MHz clock on once every 2.5 seconds (usually) and only keeps that switched on in order to receive a paging message which takes approx 20ms. After that it switches the clock off and uses a 32KHz clock till the next paging event.
Even if it is transmitting, a cell phone transmits on a completely different frequency band to that used by the avalanche transceiver (900 or 1800MHz in Europe, 850 or 1900MHz in the US and Canada ). The ARVA would have to have an extraordinarily bad design if it was influenced by transmissions in a completely different band Puzzled

A snowHead

Mike Lawrie, cell phones produce an electro magnetic field. Hence they affect the flux lines of your transceiver.

A snowHead

Tim Brown, cell phones only produce an electro magnetic field when they are transmitting! Other than that the only fields they produce are caused by the clocks switching inside the phone, which as I explained above are running at 32KHz almost all the time. An IPod would definitely produce more radio noise than a cell phone! As I also said above, the avalanche transceiver would have to be very badly designed to be affected by the 32KHz signals from a mobile phone.

Well, the person's real but it's just a made up name, see?

Mike Lawrie, the experts agree that cell phones can interfere with the flux lines of transceivers. I have two choices, to believe some bloke on the internet or the experts. I'll take the views of the experts and turn my phone off.

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Tim Brown, since I make my living from designing hardware and software for cell phones I think I can claim to understand a little bit about the subject. The only thing that I am interested in is seeing an engineering explanation as to how a cell phone manages to interfere with the operation of an avalanche transceiver, because by normal rationale it shouldn't be able to do that, and if it does then there is something seriously wrong with the specifications and / or implementation of avalanche transceivers!

I'm always sceptical about the 'expert' knowledge that's sometimes passes as gospel when it comes to mobiles. Example: for many years there were stories going round that cell phones interfere with the operation of avionics in aircraft, which finally resulted in airlines banning people from leaving cell phones switched on during flight. Finally a lot of airlines are coming round to overturning that ruling, and we are even likely to see the introduction of small base stations into aircraft so that Mr. Important can always be reachable on his mobile, even when he's over the middle of the pacific ocean Shocked

Now there's progress for you.

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"And, finally, if you are skiing with your transciever on send, TURN YOUR CELL PHONE OFF!! Our ongoing experience is that a turned on cell phone really fouls up the ability to locate a nearby transciever."

Note this bit "ongoing experience".

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Mike Lawrie, Mike, my understanding is that there have been documented but unreplicated instances of mobile phones and/or other devices causing issues with avionics. There is some controversy over the US plans to allow their use in flight.

My understanding regarding Arvas is that some empirical evidence exists suggesting that mobiles in close proximity to transceivers can reduce their efficacy. As you have such a short window of success and the things aren't that easy to use well, if there's achance that mobiles could make life in a hard place even harder, perhaps they should just get switched off?

Then you can post your own questions or snow reports...

David Murdoch, if the instances can't be replicated, I can't see how the involvement of a mobile can be much more than a guess.

After all it is free

Mike Lawrie, seems to be the same thing with mobiles in hospitals: they're said to interfere with monitoring equipment. There has been at least one guideline I've read (which is certainly based on some sort of reputable evidence) that indicated that with the old phones and 2-way radios there was a risk but that with modern cellphones there only remained a risk to certain monitoring and defibrillation equipment if the phone were actually in use within 1-2 metre of these. However, most every anaesthetist I've worked with in theatre seems to be perfectly happy to use their mobile in the immediate vicinity of monitoring equipment. Same seems to go for at least some senior intensivists in ITU. I'm interested to know what you think Puzzled

slikedges, I think the hospitals want people to use their payphones!

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slikedges, in the very early days of GSM I did in fact see one or two instances of a phone that was actively transmitting causing a computer monitor to produce a distorted picture. But it has to be pointed out that that only happened with equipment that was inadequately shielded, and I have not seen it happen for a very long time now. Likewise I have never seen a computer crash as a result of being exposed to GSM transmissions, and I spend a lot of time messing around with computers and GSM/UMTS equipment.
My understanding is that defibrilators produce short bursts of energy at high voltage ( but not much current ). Can't think of any particular reason why they should be specially sensitive to GSM, but I don't really know much about how they work so can't really comment. I guess monitoring equipment is designed to pick up very weak signals from (e.g) a person's heart, so conceivably if you place a strong radio source near the equipment, and the equipment has not been designed to filter out signals coming in at very high harmonics of the desired signal then you could, just maybe, get some spurious measurements. However, it's usually part of the tests that are carried out on such electrical equipment to ensure that they are not sensitive to other sources of energy. Not forgetting that mobiles are not the only source of radio energy floating around! I would find it surprising if such equipment is not tested for it's sensitivity to GSM (or UMTS or WIFI or BLUETOOTH or your car key or your POLAR watch etc etc ) radiation, but it's not my field so can't say for certain.

David Murdoch, Pilots make mistakes, and sometimes look for things to blame their mistakes on! Maybe the GSM related 'issues' might be found on closer inspection to have been caused by 'other' factors. You should bear in mind that on almost any flight a certain percentage of the passengers forget to switch their mobile off, and in fact it is during the critical phase of bringing an aircraft in to land that you are most likely to see a high degree of activity from the mobile phones that have been left switched on because they will all be trying to say hello to the network in the airport! If this is really a problem then you would expect to see many more mobile related avionics problems Puzzled

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Tim Brown, if there is such effect then it will certainly be measurable. I would be very interested to know if anyone has performed any such measurements, and if so what the results were. I find it very hard to believe that the makers of equipment which is intended to save lives, and who are fully aware that almost all users of their equipment will be mobile phone users as well, would not have done any testing to ensure that their equipment functions together with mobile equipment. If so then that would probably be deemed to be gross negligence on their part. I can see the American courts having a grand old time with a case like that rolling eyes

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Mike Lawrie, thanks. I'm sure what you say about modern shielding and testing to ensure normal operation in the face of all the various EMR wavelengths they may be exposed to these days must be mandatory. Many hospitals are now installing hospital wide WiFi systems.

Guys, sure, points taken. If you can't replicate it, it's difficult to solve.

I suspect that part of the aero industry stance (at least as current) is that if it turned out that there was a small but difficult to spot interaction between mobiles and avionics, and you only found out for sure in the aftermath of, say, a midair collision above central London, there might be a few red faces.

Wrt Arvas, I know there is at least one study citing mobiles as interfering with arva responses. I'll try and track it down.

You know it makes sense.

Mike Lawrie,

Hi, Mike,

My interest in the cell phone subject started last winter when after 20+ years of owning and using analogue Autophons, I purchased some new Pieps DSP units.

I had been skiing for many years with folk who had more modern transceivers, and hadn’t really understood the interference problems these were subject to, since my trusty old grid searches with the Autophon VS68 worked for me!

So, after reading loads of stuff on the net I decided to go for the latest and, on paper most sophisticated unit, the Pieps DSP. With it’s 3 aerials and ability to tell you how many signals it was receiving and especially it’s ability to ‘mask’ and ignore a signal so one could find a unit, mark it and continue on searching while someone else started digging, it seemed almost too good to be true. Sadly in my experience it was!

I purchased two of them, and train regularly (at least once a week, and at least once every day with new folk to ski with) and all last winter we were confused by occasional E codes appearing on the screen of the Pieps units when searching. I asked about these, including the supplier but never got to the bottom of it.

I entered this winter still ‘concerned’ and in early Dec 2005 attended a Canadian Ski Guide Certification course, so that I could guide with a local Heli Ski operation this winter. As part of the course we ran several rescue simulations a day, and time after time while searching my Pieps would stop showing me directions and flash up a code such as E4 or E22.

Normally when practicing searching before this particular course I’d chuck 3 or 4 old Autophons out on a slope (or on our local golf course in the fall) and search on my own, and eventually I realized that if I was searching as part of a group, I’d get a signal, start searching, and then as several of us converged on the buried unit mine would ‘blow up’ and I’d be standing while the Course leader yelled at me ‘Move fast Colin’ and I’d yell back ‘I’ve lost the ####ing signal’

Interestingly no one else on the course had a new Pieps, most had Barryvox/Marmots, and they didn’t seem to have as much of a problem.

Finally I contacted Pieps direct and received this information from them.

PIEPS-DSP & PIEPS-DSP/O Error Codes January 2005

E04 = Indication of iron masses nearby and like; all other error codes can be triggered due to interference from other electronic apparatuses. Cell phones are such a common device people forgot about them until they ring. GPS, radio communication, radios. High Voltage Lines.
Action: Turn transceiver off, rectify and or eliminate above problems, turn transceiver on and continue.

E22 = Receiver strength is effected on all three antennas due Iron masses nearby, or other electronic apparatuses signal interference or having another beacon interference nearby (less than 5 meters.)
Action: Turn transceiver off, rectify and or eliminate above problems, turn transceiver on and continue

E23 = Reinforced receiver amplification interference due another beacon nearby (less than 3 meters) or other electronic apparatuses signal interference.
Action: Turn transceiver off, rectify and or eliminate above problems, turn transceiver on and continue

E25 = Transmit frequency is outside the acceptable range due another beacon near by (less than 3 meters) or other electronic interference.
Action: Turn transceiver off, rectify and or eliminate above problems, turn transceiver on and continue

E27 = Processor problems: The transceiver is defect and is no longer aloud to be used, even if the problem has disappeared.
Action: The transceiver must be returned.

It thus seems that at Pieps they know that any other electronic apparatus operating near a Pieps when searching will cause sufficient interference (or distortion of the flux lines?) for the Pieps to loose it’s ability to search! As a result of receiving this information we junked the Pieps units and purchased Mammuts which are by far the most common units here.

If you look at the literature that comes with most transceivers the manufacturers recommend that all cell phones and other electronic gear are turned off when using a transceivers.

This example is taken from page 18 of the Tracker manual:

Do not place cellular phones, communication radios, or any other electronic
equipment within 6" (15 cm) of the Tracker DTS while performing a transceiver
search. In receive mode, irregular readings can be caused by these
and other sources of electrical interference, such as power lines, electrical
storms, and electrical generating equipment.

And this from page 6 of the Pieps manual..

IMPORTANT: All participants (including observers) must switch their
devices to receiving (SEARCH) mode. Always make sure there are no
electronic devices (e.g. mobiles, radios,) or solid metal items in the direct
vicinity of the search.

So although I’m not a technical person, I now ask (actually I insist) everyone one in a group that I am skiing with off piste to turn their phones off and to place them in their backpacks, away from their transceivers. And strongly recommend it to others too.

I've never had to search for real, but if I do I'd rather as many potential problems were elimanated, but if your technical knowledge tells you otherwise, who am I to argue!

Your choice,..... your life!

Otherwise you'll just go on seeing the one name:

I don't know about the exact technicalities of this situation, but there does seem to be a lot of modern mythology surrounding mobile phones. I think that often something starts as a rumour, and then if it sounds plausible it gets repeated again and again by more and more people until it gains it's own momentum and comes to be accepted as the "truth". Added to this there is the pressure to take the perceived "safer" option, especially if it's also the cheaper option (it costs almost nothing to ban something, it takes a lot more time and effort to actually find out about it), and it's not wonder that mobile phones often get the blame for something when there really is no need. As mentioned above, this seems to be the case with mobiles in hospitals, mobiles on planes, and mobiles on garage forecourts.

It would seem that an easy option for avalanche beacon manufacturers is to ban the use of mobile phones rather than work out whether they actually do interfere with the operation of their beacons. It would seem that two way radios are just as likely to interfere (if not more so as they are constantly receiving) with avalanche beacon operation.

Finally, just because the vast majority of people believe something to be true, doesn't necessarily make it so. If this were the case then there would never be any intellectual progress.

A snowHead

Kramer, well said!

I've heard that the 'problem' with phones on forecourts is the possibility of them getting dropped and the battery disconnecting and shorting across something with a spark. OTOH, I don't know if this has ever happened, and the actual advice is 'turn your mobile off' which is just as likely to precipitate such an accident.

A snowHead

Kramer, beacon manufacturers have no power to 'ban' mobile phones. Will your phone be on or off the next time you ski with a beacon attached?

Well, the person's real but it's just a made up name, see?

Tim Brown, ok they have no power to "ban" the use of mobile phones, but the cheaper option for them is to advise that they're turned off. It's also guarenteed to be a safe option, but that doesn't necessarily mean that it's true, it's just an easy way for them to cover themselves legally.

I wouldn't ski with a beacon with my phone switched on, because I don't know enough about the details of the technology to make a different judgement, all I'm saying is that often even though these things are repeated with authority, it doesn't make them true.

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colinmcc, I see what you ( and the Pieps manual ) are saying, but it still doesn't add up for me.
You say you had problems when your group of searchers converged. Did the problems with the Pieps disappear if they all switched off their mobile phones? Because if that is not the case then I would suggest that the problem lies in having a bunch of other search devices (Barrivox or Marmot) which are receiving on the same frequency as your Pieps was doing. I could quite easily imagine that the IF radiated by the other receivers could cause your receiver to do unspecified things. Like de-tune itself. Possibly.
I would also say again, that if Pieps have known problems of this nature, and they throw their device onto the market anyway, then they are acting in a highly irresponsible manner! Imagine the litigation that would ensue if it turns out that people had died because their device didn't function in the presence of other common equipment! I think they would have a hard time pointing to the manual and saying that covered their asses

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Kramer, exactly right. It's a similar sort of thing for large parts of the lists of adverse effects and contraindications on the paper leaflet that comes with medications. It's often financially safer and easier for the drug company to warn of something which they perceive possible or has barely been reported with no association being clearly demonstrated, in an effort to evade their medicolegal responsiblity. If you took the whole list of potential adverse effects seriously, you'd never even dare take a Vitamin C tablet. It's standard practice with many drugs not to test them to see if they can be used on children or in pregnancy, but merely to say that they're not recommended, because testing them wouldn't be financially favourable.

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Kramer & slikedges, didn't I just read that the largest ever study of the effect of mobile usage on brains found ... nothing, contrary to all the scaremongering that's done the rounds for 10 years past? I'm sure I exaggerate, but I think that was the gist.

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laundryman, we're not talking about hospital, medicine, peoples' brains or aeroplanes, we are talking about transceivers. As with all safety equipment, the user should follow the manufacturers instructions.

After all it is free

Tim Brown, some people are intellectually curious and like to ask 'why' questions. You can skip over them if you like.

laundryman, exactly.

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laundryman, if you end up buried, and while your waiting to be dug out your phone starts to ring, you can always ask yourself if it's screwing up the search patten. The important thing to remember is that the experts agree mobiles can adversely affect transceivers.

Is there anyone here who will leave theirs on while attached to a beacon?

Help!!

Transceivers - anyone carry them on piste/in bounds

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