On Feb 22, 6:23 am, Daniele Fua wrote:
I am looking around for an AIS receiver, good and not too expensive. I
am a sail cruiser. Is there any strong reason for buying a true 2
parallel channel receiver? I found this receiverhttp://www.yachtbits.com/easyais/easyais_ais_receiver.php
which appears to be quite good but it is not clear whether it is truly
parallel or duplexing.
Any advice?

Regards
Daniel

The AIS system has the ship's transmitter alternating the two
frequencies on a sporadic interval but have all information
transmitted every five minutes. Using one channel means you'll get the
vital data i.e. position, course and speed frequently enough but all
the other ship's data would be slower coming. AIS uses channels within
capability of your VHF radio, 161.875 and 162.025, but most don't
decode the signal (wait and see for the next round of DSC / VHF
radios?). You can get the signal using a plain old VHF scanner and
decode it using your laptop or PC, if you want to do it on the cheap,
see ShipPlotter.com and http://www.discriminator.nl/index-en.html for
which scanners work and how to get the signal to your laptop.
The device you've identified above only gives the raw NMEA ascii
data over a serial line. You'll need a compatable front end device to
display it, ie. Furuno, Garmin, etc ($$$$) GPS plotter. OBTW you will
need a GPS to show where YOU are on any unit unless you want to
reduce LAT-LONG readings in your head. [: