"Len Krauss" wrote in message
...
Ric,

That sounds like it could work with my handheld GPS, with it and the GPS
powered by boat's battery. Of course my GPS 48 has no alarm-out
connection.
But, I wonder how hard it would be to open the GPS case and find the
internal audible alarm device contacts and give it a try.


That's what I did. I just found the feeble little buzzer, soldered some
leads to it, fed it to a MOSFET gate, then used the battery to power a
siren.


Thanks,
Len


--
You don't mention what kind of GPS you have - but are you sure there is
no
means to connect an external alarm? My GPS (a Raymarine 420) had a
totally
useless "alarm" that wouldn't wake a sleeping mouse, so I pulled it to
bits
and connected an external alarm. I subsequently discovered that
Raymarine
will actually do this as a free after market mod, realising that it was
a
bit dumb to ever build something with an inaudible alarm.