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Sledhaulingmedic
01-22-2009, 08:56 PM
From an Email from National Ski Patrol:


PIEPS GmbH of Austria, one of several manufacturers of avalanche rescue transceivers, has become aware of a potential issue involving carrying the PIEPS DSP avalanche transceiver in close proximity to the Motorola Model GP340 radio transceiver. Although the GP340 radio is a European version, it is very similar to the Motorola HT750 series used in North America.

Avalanche rescue transceivers are extremely sensitive devices, and can be affected by the magnet found in a radio speaker. If the radio, or even a speaker-microphone, comes in close proximity with the avalanche transceiver, magnetic fields are present that can activate magnetic switches in the PIEPS DSP to turn it off or change it from transmit mode to search mode. This is NOT a Motorola radio issue-this is NOT a radio frequency issue-it doesn't matter if you are using VHF, UHF, or 800 MHz radios-it's a magnetism issue that apparently affects other transceiver brands and models as well.

The manufacturers of avalanche rescue transceivers also caution users against wearing clothing containing permanent magnets (e.g. magnetic button closures, magnetic nametags) while operating avalanche rescue transceivers.

The issue is being investigated and is of no immediate cause for alarm. It does not appear to affect transceivers that are carried according to the separation criteria already specified in the PIEPS DSP owner's manual (at least 15 cm [6"] from other devices while in "send" mode, and 1.5 m [approx. 5 feet] while in "search" mode).

However, the situation should serve as a reminder for all users of avalanche transceivers to read their owner's manual, and observe the criteria specified for separation distance between their transceiver and other potential sources of magnetic interference, regardless of brand or model.
Mike Laney Dick Woolf
National Avalanche Program Director National Telecom Advisor

RR
01-22-2009, 10:36 PM
Reps for taking care of business!

Nicely done, sir!

Potential Rule three: "Watch it with that magnet!"

bucksaw
01-23-2009, 07:36 AM
there are a some of head lamps that can interfere with avalanche beacons too. I have a Princeton Tec Corona the box had a warning on it regarding Avalanche Beacons. Something about electronics in the light may interfere with an avalanche beacon in receive but not in transmit mode.

yuckster
01-23-2009, 08:19 AM
instructions for BCA tracker say to keep it separated from other devices by, if I remember correctly, 6 inches - which is quite a bit less than was recommended at the avy course last weekend...

PWDR8S
01-23-2009, 10:56 AM
Magnetic reps to Sledhauler! I suspected there may be issues like that and now this proves it!

Now what to do with the radios and fridge magnets I always schlep around!?! :rolleyes:

Sledhaulingmedic
01-26-2009, 01:58 PM
Magnetic reps to Sledhauler! I suspected there may be issues like that and now this proves it!

Now what to do with the radios and fridge magnets I always schlep around!?! :rolleyes:

Never mind the magnets: stop hauling that fridge around!

RR
01-26-2009, 02:39 PM
Magnetic reps to Sledhauler! I suspected there may be issues like that and now this proves it!

Now what to do with the radios and fridge magnets I always schlep around!?! :rolleyes:Never mind the magnets: stop hauling that fridge around!
Zing!

PWDR8S
01-26-2009, 02:43 PM
Yeah..... I suppose the ambient cold air should be chilly enough for my beers. :rolleyes:

jshefftz
02-17-2009, 07:46 PM
Previously in my testing I had noted that the ARVA 3 Axes turns to On/Transmit by inserting a little plastic piece with a magnet on its end. The beacon could therefore be turned to On/Transmit by placing any sufficiently strong magnet in close proximity to the insertion point.

I didn't realize though that a beacon switch that *looks* mechanical could in fact be magnetic.

So I took a couple magnetics from the fridge:
-- 18mm diameter x 4mm thick
-- 20mm diameter x 6mm thick
. . . and tested all the beacons on the market (except for ARVA) by turning them to Transmit, then seeing if either magnet could affect the beacon.

Only the Pieps DSP was affected. With about 3cm, the smaller magnet consistently turned the DSP to Search, whereas the larger magnet turned to the DSP to Off. When each magnet was removed, the beacon returned to Transmit.

I tried tracking down a jacket with magnetic-closure buttons for testing, but so far I've been unsuccessful.

yuckster
02-17-2009, 07:52 PM
hmm, better get that steel plate removed from my skull ;)

PWDR8S
02-17-2009, 09:55 PM
Guess I have to give up the ol pacemaker. :(

jshefftz
02-28-2009, 10:11 PM
Interesting discovery: even the weak magnet found in a pair of gloves (apparently to keep them together?) can have this same effect.

Sledhaulingmedic
03-01-2009, 08:56 AM
hmm, better get that steel plate removed from my skull ;)

Upgrade to titanium. Save some weight.