On Thursday, April 3, 2014 7:27:46 PM UTC-7, Brian wrote:
What happens if you moving when you activate it?

If a GPS model how often does it update the postion?

Brian

Read the manual for your particular unit. Then read it again. And make sure there is a manual or instruction sheet packed with the device. Any of these devices including InReach and SPOT, if really in distress there is stuff in the manual you may need to know.

Most modern PLB typically acquire a GPS fix fairly quickly (~ minute) and then renew that every 30 minutes. So if you move PLB the GPS location will be slightly inaccurate for some time. Obviously these are intended to deal with walking/drifting speed type movements where it is not really an issue. With many searchers that will also do final homing on the beacons (406 or 121.5... in many cases it will be 121.5 MHz). Regardless of GPS data, when you activate the PLB a signal is sent and received within about 1 minute and contains your PLB unique serial number registered to you, and the SAR organizations will start things based on that even if it does not have your location information (say you are down in a canyon or under a heavy forest canopy and cannot get a GPS fix). And in that case the polar orbit SARSAT satellites will start triangulating your fix if they can see the (relatively powerful 406 Mhz beacon) signal and they'll often have a good location to within a few miles within ~30 minutes or so. Put the PLB somewhere with a good sky view and the beacon antenna properly erected and don't move it around or dick with it, so the satellites can do their stuff.

And read the manual about how to do proper tests on these devices, and do them.

The SPOT and InReach have more usability issues/confusion that a relatively simple PLB. What do the different LEDs *really* mean? If a SPOT status says there is no GPS fix are track, OK, or HELP messages sent at all? I know everybody knows the answer to all those questions... right? In a bad situation you will want the manual packed with you.

Darryl