Paul wrote:
"Paul" wrote in message
...

"Gordon" wrote in message
...

Anybody have any experience with the SR161 AIS receiver from Milltech
marine?

I just got one, and it is running on my desk as I type. It is in a metal
box, similar to the NASA plastic box unit (or maybe a little smaller), and
it seems to have similar sensitivity. My location is on a ridgetop a few
miles from the ocean, at about 1000ft elevation, and with an 8ft VHF whip
antenna I can receive out to about 40 miles max. I haven't taken the box
apart yet.
[etc]


The range is actually better than 40 miles, I discovered. My computer is
pretty close to the antenna, and must be putting out significant R.F. noise.
I've been able to receive beyond 60 miles when the computer is off. This is
hardly a scientific sensitivity test, though. I'm using a PocketPC to
decode the NMEA data from the SR161, and the PPC puts out less noise than
the PC.
-Paul



I am quite interested in this topic but I have a question: isn't the AIS
system meant to rely on transponders, i.e. on Transmitters/Responders?
If so, a plain receiver like the one you write about is bound to receive
the information only from the vessels that were "excited" by someone
else. Is it so?

Daniel