My New Handheld AIS Receiver . . . WOW !

[Triton318]

How about buying something like this -- ACR Nauticast AIS Receiver -- and having the NMEA 0183 Interface output from the AIS receiver go to a little DIY box that beeps when a signal is received?

[barnakiel]

Originally Posted by conachair

Dunno how it works. I can't get 87b or 88B on my vhf to have a listen, but nothing obvious on the ham radio on those frequencies so maybe it is.

Are the clicks loud enough to open up the squelch?

Some of them do while others blip with a momentary 'busy' msg on the lcd screen.

BTW Why 87/88 B, not 87/88 ?

b.

[barnakiel]

Originally Posted by Triton318

How about buying something like this -- ACR Nauticast AIS Receiver -- and having the NMEA 0183 Interface output from the AIS receiver go to a little DIY box that beeps when a signal is received?

No need to build things. MerVeille makes them already.

b.

[Paul Elliott]

One potential problem with a very simple "AIS Received" alarm is that under certain radio propagation conditions the range for AIS reception can extend to hundreds of miles. On many occasions I've received signals from boats in excess of a 200 NM range -- this is with a spreader-mounted antenna. With a (for example) stern rail-mount antenna my maximum receive range still exceeds 100 NM.

The guaranteed range is essentially line of sight, but this extreme range propagation is fairly common during certain weather conditions.

My concern is that an alarm that triggers at 50+ NM will become a nuisance and not a help. You can of course design (or buy) a system that uses a GPS input to calculate the ship's range and trigger an appropriate alarm, but this involves more than just an activity detector.

[teejayevans]

Originally Posted by teejayevans

Buy the following:
$25 VHF Antenna
$150 Get a AIS rcvr (ACR nauticast mention above)
$50 USB GPS rcvr
$275 Netbook computer, install OpenCPN
Total $500
Its portable and can be contained easily in a small briefcase.

This setup will consume approx 2 amp-hours, works off shore, can be turned on when needed, maybe for a few mins, a single hander can check if any ships in the area, then can take a nap if all clear using the AIS proximity alarm to wake himself up, turning it off when their awake to save power.
Tom

[barnakiel]

And here a link to the toy I mentioned:

index

It takes in your GPS input so apparently no false alarms when the ship is never ever to go into the collision zone with you. Very low power draw too.

Cheers,
b.