Sending "I'm OK" message using a standard Emergency Beacon

One thing I've learnt is don't test those suckers around any electronic kit like speakers or computers.... they send out a fairly powerful signal... will light up any speakers nearby...

Mike , why is it that I see a basic fault in the instructions on the link you provide ? 'point the Aerial to the equator ect' ,,, break the seal and point the Aerial ! Yeah right ! Moving the Aerial from the safety sealed position activates the unit .... Nothing to do with the test function at all ,, the test function is to ensure the batts have still got power , no signal sent.

Oh Mike , did you bother to check the coverage they are offering to cover for your $39.95 or the " extras" at $59.95 , ? NONE is applicable to AUS.

When you press the test button on an epirb/plb it does transmit, the satellites can detect it but it will be discarded because of the test code. Although the discarding will use up processing functions on the satellite.

The test itself isn't designed as such to communicate with the satellite (as in it isn't checking it can communicate with it), which is why there is not a requirement to deploy the aerial.

406link will require you to deploy the aerial, which if you have ever used some brands can be a pain afterwards (breaking the seal can make it difficult to keep it in place)

The real consideration about this service is battery life. Every time you use it (or test your beacon) you are using up battery power. Manufacturers provides guides to how often you should test your beacon, so it will retain enough power to transmit for at least 24 hours (48 for epirb, 24 for PLB) when you activate it in distress.

406link is a service by ACR, but is available for all beacons (may be dependent upon beacon type TBC). Of interest is that the latest ACR beacon (which has an okay button built in) only allows you to test GPS functionality up to 60 times over the life of the battery.

Even if coverage is extended to Australia, I would recommend that you check with your own manufacturer before taking it on. The battery life is going to be a real consideration

There is also some info at (look for "Self-test function")
http://beacons.amsa.gov.au/beacon-testing.html

Regarding the power, yeah the 406 component transmits at 5W, the 121.5 component is much less (0.1 to 1w is average)

It might be better to keep your epirb as an epirb, and consider Spot if you want to send 'I'm OK messages'