This was a 3 hour avalanche transceiver session held in Glenmore Park. The intent was for an in-depth chance to not only review some common practices, but also better understand how transceivers function by playing and experimenting with them and with different variables that affect their performance.
The main topic areas included:
-The nature of transceiver signals;
-Interference with transceiver signals and reception;
-Transceiver checks.
The session started with people working in pairs doing a couple basic single beacon search exercises, including one with the beacon in a known visible spot. This illustrated how the direction arrows displayed on a receiving transceiver follow the sending transmitter’s flux waves (not a straight line!). This can be a little confusing at first, but if anyone had any doubts about the arrows shifting around on their display and whether to trust what they were seeing, a group exercise then provided reassurance in showing how everyone else’s beacons also displayed differing directions and distances all while searching for one common transmitting signal. Trust the transceiver!
We then experimented with different variables, and found that the orientation of transceivers in different planes influences signal strength and direction. With sources of interference, notably cellphones, but also other items commonly carried such as e-gloves, etc., a general observation and conclusion was that interference is greater on the searching transceiver than on the sending transceiver. And so the ‘20-50 rule’: sources of interference should be at least 20 cm away from where the transceiver is carried on one’s body while travelling, and then kept at least 50 cm away during any searching. Remove the e-gloves while searching and keep the cellphone away!
Another exercise focused on the multiple burial function/display of beacons. For this, people were mixed in small groups of 4-5 people with different transceivers. At least a couple folks expressed, how they probably need to get a newer beacon, and how when they got home they would be reviewing the instruction manual for their transceiver.
Lastly, a sampling of different methods of doing group transceiver checks were tried. While there are many transceiver features that can be checked, which method is optimal on any particular day may depend on various risk factors (terrain, avi hazard, etc.) including how well participants and trip coordinators know people’s familiarity with their transceiver. Someone reminded me that having people run through a detailed group check in a session like this is part of the point of the Ramblers’ avalanche policy. It then provides assurance to all on any given outing, that everyone knows how to use their transceiver.
Being a focused, urban, flat-land, half-day, snow-less session, the skiing unfortunately sucked. Everyone is encouraged to also attend one of the full-day field sessions being held that will cover other required topics such as probing, shoveling and large scenarios.
Thanks to everyone who came out. Also special thanks to Gord for his assistance and to Carl, Steve and Bill for bringing along extra transceivers.
Scribe & Coord - Marcus Eyre
Participants: Philip, Bill, Arnold, Gerald, Alda, Mike, Jeannine, Carl, Jane, Joanne, Vi, Pam, Gordon, Jenny, Richard, Katrin, Steve, Marcus, Aga, Rick