Motorola has systems like that -- they're very expensive
(and rugged and reliable).

The range you're looking at is a stretch for most consumer type
off-the-shelf equipment. One creative way to do it would be to
use inexpensive 802.11 wi-fi hardware with VOIP running between
the nodes.



wrote:
I have an application where a truck will pull onto a scale, the driver
will press a call button and a wireless talk path then must be opened
up to a distant office. The office is abouut 2000ft. away from the
scale. We would prefer hands feee VOX perhaps talk and listen on both
ends, in fact duplex if available would be great. Does anyone know of
such a system? Thanks. Lenny Stein, Barlen Electronics.