On 11/12/2010 22:00, Ace wrote:
On Thu, 11 Nov 2010 23:38:01 +0000, jakemosterio

As for compatibility, all beacons (for the last 20-odd years, at
least) use the 457MHz frequency, so there should be no issues
whatsoever with searching for older models or vice versa.

Just a small correction, the frequency that is widely used is 457 kHz
not MHz. This is important for the units to work actually as with this
low frequency you are actually probing the near field of the dipolar
transmitter antenna. The most advanced search strategies and also the
fancy new 2 or 3 antenna devices rely on that fact. There are new
developments for beacons that also take advantage of the multiples
antennas present in transmit mode as they can basically detect the
orientation of the device by means of a gravitational sensor and switch
to an antenna that allows for effective searching (a dipolar antenna
pointing perpendicular to the surface leads to the worst coupling and
should be avoided.)

Bernd