Joq said: Mark I eyeball... still have to identify you from a lot of choppy, busy water. I'm 7 days away from buying a small PLB (with GPS, a McMurdo Fastfind 210) for our trip to Alaska's outside coast - so this all has a certain resonance for me ;-) Can you shed any light on the claims made by the makers of the current crop of small personal beacons (EPIRBs & PLBs - not SPOT) that SAR can/will use the units' secondary 121.5 MHz locating signal - "they use the position and 121.5MHz to home in on you." The primary beacon transmissions are on 406 MHz (to the COSPAS-SARSAT satellite system) and they receive on the GPS frequencies (from the GPS satellites) - so the 121.5 MHz signals seem to have no other purpose than as a 'homing' function for that last few 10's or 100's of meters in the rescue process. That's assuming that the last GPS fix and 406 message (received by SAR through the satellite linkage) has pinned down your location to within that same limit of 10's of meters if very fresh - or 100's of meters if somewhat stale and there is significant drift... So what is there in the SAR cockpit that says 'go left' or 'go back' as the pilot homes in on a 121.5 MHz signal over a black ocean ? Is that the time for a hand-held flare (pyrotechnic or laser) or LED torch, or do you stand out on his LCD screen like a 'flare' (of 121.5 radio transmission) anyway ? Best Regards Paul Hayward, Auckland, New Zealand *************************************************************************** PaddleWise Paddling Mailing List - Any opinions or suggestions expressed here are solely those of the writer(s). You must assume the entire responsibility for reliance upon them. All postings copyright the author. Submissions: PaddleWise_at_PaddleWise.net Subscriptions: PaddleWise-request_at_PaddleWise.net Website: http://www.paddlewise.net/ ***************************************************************************Received on Wed Jul 07 2010 - 19:02:43 PDT
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