On Mon, 25 Aug 2003 00:26:46 +0000, "Uncle StoatWarbler"
wrote:

On Sun, 24 Aug 2003 19:35:16 +1200, Barry Lennox wrote:

The 406MHz COSPAS/SARSAT ones are much more accurate, typically about
200-300metres just from a satellite fix, but they are also much more
expensive. Depends on how much you are worth!

It won't be long before the new generation combines a gps fix with the
distress squawk.

They already exist right now, and have done for about 6 years, but
they are expensive, and that won't come down too much. The problem is
the 121.5/243 MHz ones cannot support embeddded data, and
COSPAS/SARSAT plans to stop monitoring these freqs in 2006 (I think,
maybe 2008) because of this limitation and the VERY high rate of false
alarms, over 90% in most countries, inc NZ.

The 406 MHz ones certainly support embedded data, but you pay a lot
for them. The big cost driver is the very stable oscillator required,
plus the many thousands required for certification.