Hi,

I Think everybody has this problem until he receives the first ship
with his AIS receiver. This happen to me me and many friends, do not
worry.
1) The first thing you must do is tune your normal VHF radio to
channel 87 or 88 and ear the AIS bip sound; if you do not ear the
"tlack" every few seconds, probably you do not have any ship near
transmitting AIS signals.
2) Second, if you ear the AIS sounds on your VHF radio channels 87/88,
them see that your plotter or laptop is set to NMEA 38400 bauds.
3) The SR161 has two lights, one blips when it receives an AIS radio
signal, the other blips only when and it has success decode the AIS
signal and are transmitting the NMEA AIS signal decoded to the
plotter.

Good luck

Pascal






On 6 jul, 13:09, Larry wrote:
dansk wrote in news:1183730944.119497.309510
@g4g2000hsf.googlegroups.com:

I have installed an AIS receiver in our vessel with which we travel
Long Island sound NY. So far I have never seen an AIS contact, I am
beginning to wonder if the unit even works. It is a millitech SR161.
Has anyone seen a contact in this area?

Bob

Make SURE its NOT connected to the same antenna as a VHF transmitter! I
keep finding little AIS receivers T'd into the coax with a 25W
transmitter, the AIS receivers burned all to hell!

To check out your AIS VHF antenna, unplug the AIS receiver from it and
plug in a VHF marine transceiver or walkie-talkie. Make a radio check
call and see if anyone can hear you. Check the SWR if you have a meter.
AIS uses the same band/antenna. If the antenna won't work for your VHF
radio, it won't receive AIS signals, either.

Now....How are we receiving the data from the SR161? AIS receivers do
NOT run the same speed as NMEA data networks and cannot be used with them
unless you have a special multiplexer that can convert the data speed.

With so many laptops NOT having an obsolete RS-232 serial port any more,
you need an RS-232C to USB adapter cable AND THE DRIVER TO GO WITH IT so
the computer tricks the AIS software into THINKING it has a COM (serial)
port. The RS-232C MUST BE CONFIGURED FOR 38,600 BAUD, No parity, 8 bits,
1 stop bit. (N-8-1)...

You can use a dumb terminal program like Windows' Hyperterm (Click START
then ACCESSORIES then COMMUNICATIONS then HYPERTERM to wade through
Windows XP to boot it.) Once Hyperterm is up click CALL then CALL again
and just give it any name. When the speed window comes up pick 38,400
baud N-8-1 and the COM port the USB driver is watching.

Sure wish the damned fools who make AIS weren't living in the 1970's and
just put a USB jack on the damned receiver....Sure make life easier for
all.

Larry
--
While in Mexico, I didn't have to press 1 for Spanish.
While in Iran, I didn't have to press 1 for Farsi, either.
It just isn't fair.