On May 25, 9:58 am, jmr wrote:
Hi Tom,

You probably already know this, but even with a class B transponder
you'll still need some way to display received info.

Good point. The Verper unit plus a pc for close calls is what I'm
thinking of now.


The multiplex receivers work well and work much better than the single
channel units. But they may only deliver every other message (if the
ship is transmitting every two seconds, they deliver data every four).

Right, but I'm worried a little that they need to get a complete
sentence/packet (not sure of the system details) and I wonder if they
couldn't find themselves missing many packets because of bad timing.
Does the protocol take care of that somehow?
....
When looking for a display I'd recommend seeing if it computes CPA, how
many targets it can handle and whether its AIS receiver can be upgraded
later to a class B transponder when they become available.

Yes CPA/TCPA are the big selling point for me. One reason I don't
like the NASA AIS Radar is that you get to plot that on a tiny PPI.
Not all the units I've looked at mentioned the number of targets they
could track. I think the AIS system has some kind of filtering built
in. Is there a problem w/targets getting dropped?

Cheers,

-- Tom.