New Zealand Mountan Safety Council

Online Course - Rescue - Transceivers

Transceivers are electronic devices (worn by each person) that transmit a radio signal. In the event of an avalanche, searchers can switch their transceivers to search mode and follow the signal to the buried person.

A range of transceivers are imported into New Zealand. All transmit on 457 kHz and are compatible with each other but differ in the way they display information and what other functions they can perform.

Digital transceivers convert the signal from the buried set into visual distance, direction indicators and audible signals that aid the searcher. Older analogue transceivers do not apply any enhancement to the signal; the beep you hear is the actual unprocessed signal from the transmitting set and a change in volume indicates that you are getting closer to the buried signal.

The most important thing is to understand how to use the features on your transceiver and PRACTICE, PRACTICE, PRACTICE.

Using your Transceiver

Every transceiver has a different way of turning on, switching to search and indicating where the buried signal is coming from. Read the manufacturer’s instructions and learn how to operate the one you have.

  • Put your transceiver on before you make your first step onto the snow. Wear it under a layer of clothing and leave it switched on at all times.
  • Check everyone’s transceiver is transmitting properly. Repeat this check two or three times during the day. Get one person to listen while the others file past one at a time. The last person then checks the first person’s transceiver before the party sets out.
  • Ensure that the transceiver is more than 50cm from any other electronic equipment such as a cell phone, camera or radio. These devices might interfere with the transceiver’s ability to operate effectively.
  • Check and change you transceiver batteries regularly. Use Alkaline batteries. Never use lithium or rechargeable batteries as the range and working life of these batteries is significantly shorter. Remove the batteries for the summer and replace with new batteries for winter.

Signal Search

Coarse Search

Fine Search

Pinpointing with a probe

Move fast, you are trying to find the buried person's signal

  • Use a 40 metre search strip width in order to pick up the buried person’s signal.
  • All electronic devices such as cell phones, cameras or radios should be turned off or have at least 50cm separation from the transceiver to avoid interference.
  • Look at the avalanche path for visual clues as you search.This may be the victim's gloves, hats or equipment.
  • Swiveling your transceiver right and left and tilting it up and down helps you orientate it with the field lines being transmitted from the buried set, and so assist your search. When you pick up a signal, shout SIGNAL to inform the rest of the searchers and follow the indicators on your transceiver.
  • If there are other people buried, the initial search should continue while one rescuer follows through to the next phase (Coarse search).

Move as fast as possible. You have heard the signal and are trying to narrow the likely burial spot down to a small area.

  • Follow the indicators on your transceiver. Once your transceiver indicates that you are 10 metres away from the buried victim, slow down.

Slow down and get down You have identified a small area and are looking for the place to probe and dig.

  • When you are within 3 metres of the buried person, start moving very slowly and systematically.
  • Get down on your hands and knees and with your transceiver close to the snow, move it along the surface in a straight line. The signal should usually get stronger before weakening. Keep going until the signal weakens then go back to the area of the strongest signal.
  • Keeping your set oriented the same way, move it at right angles to your first line until the signal fades away. Then move back in the opposite direction until you find the strongest signal again. Repeat to the other side of the strongest signal.
  • Mark the spot and start pinpointing with a probe.

 

  • Use your probe to find the buried person and their depth of burial. Start from the point with the strongest signal and probe 25cm apart in an outward spiral. Be systematic and precise.
  • The probe should always be perpendicular (90°) to the snow surface.
  • Once the victim has been struck, leave the probe in place.
  • If you don’t have a probe, start digging and use further fine searching with the transceiver from within the hole to find the victim.
  • Only use the marking function once you have a confirmed strike.

 

  VIDEO - Avalanche Transceiver searching techniques

 

 

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