Anybody have any experience with the SR161 AIS receiver from Milltech
marine?
Seems reasonably priced.
Gordon
--

Ask not for whom the terrorist bell tolls; it tolls for thee, and thee, and
thee--for decent, innocent people everywhere.

"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

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

On Mon, 13 Mar 2006 16:36:32 GMT, Daniele Fua
wrote:


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

Vessels underway transmit their position, heading and speed every
second or so, depending on speed, and full data every six minutes.

They do not wait until interrogated.


--
Peter Bennett VE7CEI
email: peterbb4 (at) interchange.ubc.ca
GPS and NMEA info and programs: http://vancouver-webpages.com/peter/index.html
Newsgroup new user info: http://vancouver-webpages.com/nnq

"Peter Bennett" wrote in message
...
On Mon, 13 Mar 2006 16:36:32 GMT, Daniele Fua
wrote:


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

Vessels underway transmit their position, heading and speed every
second or so, depending on speed, and full data every six minutes.

They do not wait until interrogated.

This is correct. The transmitters are indeed transponders, though, since
they have the capability of responding to a specific interrogation, and they
participate in the coordination of the timeslotted transmissions from all
local transmitters.

The receive-only units are much simpler, as they only have to listen.

-Paul

Have you seen the SR260/SR261 from Smart Radio? It is a
receiver/transmiter, but not a "full AIS Class A/B" and do not have
oifical homologation yet, but can save lives.. I am waiting the AIS
support on Garmin chart ploters (pheraps this month?) to buy a complete
package (AIS receiver/transmiter, user friendly low 12V consumer, color
Gps/Chart/Ploter, not a laptop PC).

On Mon, 13 Mar 2006 18:49:59 -0500, Larry wrote:

While an AIS receiver is a great toy at this time, I'd wait until the
yachtie versions of the full AIS transmitter/receiver/display units come
down in price to something reasonable and buy that, instead. Just
receiving will do you no good when you're at sea and the containership is
bearing down on you at 15 knots. Having the transmitter makes you stand
out just as big as the next 950' containership!

Don't be foolish. Although future affordable class-B transponders
will be great, currently available cheap receive-only units are still
great assets. Detecting the big ships 20-40 miles out, and having
accurate collision warning is very valuable. Not to mention the ship
name and MMSI number making radio contact easier and more likely to be
successful.

--
BRENT - The Usenet typo king.
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"Brent Geery" wrote in message
...
On Mon, 13 Mar 2006 18:49:59 -0500, Larry wrote:

While an AIS receiver is a great toy at this time, I'd wait until the
yachtie versions of the full AIS transmitter/receiver/display units come
down in price to something reasonable and buy that, instead. Just
receiving will do you no good when you're at sea and the containership is
bearing down on you at 15 knots. Having the transmitter makes you stand
out just as big as the next 950' containership!

Don't be foolish. Although future affordable class-B transponders
will be great, currently available cheap receive-only units are still
great assets. Detecting the big ships 20-40 miles out, and having
accurate collision warning is very valuable. Not to mention the ship
name and MMSI number making radio contact easier and more likely to be
successful.

Agreed, a receive-only collision alarm is *much* better than nothing. Even
though the big ships will be much more likely to notice you by AIS than by
radar (if you have an AIS transponder), my plan is to assume they don't see
me and stay out of their way. For the other smaller boats with receive-only
units, having a transponder is obviously a better choice. Of course, many
smaller boats will have no AIS at all.

While I am waiting for the class-B "yacht" transponder, I will definitely
have the receive-only unit on-board. Regardless, you still need to keep a
visual/radar watch going.

The SeaLinks RADARPLUS SL162B transponder may be the ticket, but I don't
think it has been released for sale yet.

-Paul

"Pascal" wrote in news:1142294909.882724.90990
@p10g2000cwp.googlegroups.com:

Have you seen the SR260/SR261 from Smart Radio? It is a
receiver/transmiter, but not a "full AIS Class A/B" and do not have
oifical homologation yet, but can save lives.. I am waiting the AIS
support on Garmin chart ploters (pheraps this month?) to buy a complete
package (AIS receiver/transmiter, user friendly low 12V consumer, color
Gps/Chart/Ploter, not a laptop PC).



No, haven't investigated that one. Got a webpage address?