I recently bought a dAISy AIS
receiver. While waiting for an antenna
and adapters to arrive I passed the time looking around on eBay and found a few other devices that might be of interest.
The Quark-Elec QK-A021 appears to have similar specs to the dAISy. It's price
is less than the dAISy but when you add shipping
it costs more.
Marine/ship/boat AIS Receiver(USB connector)--UK seller | eBay
The Quark-Elec QK-A022 is a dual channel receiver.
Marine/ship/boat Dual Channel AIS Receiver--UK seller
Both publish specifications, which are lacking from the dAISy manual or Web pages.
If you want to be seen by other AIS-equipped vessels there some fairly inexpensive AIS
transceivers are beginning to appear.
The Matsutec HA-102 is the cheapest.
CLASS B AIS Transponder HA-102 Dual Channel Function CSTDMA Function | eBay
Next is the Matsutec HP-33A.
4.3" Color LCD Class B AIS Transponder Combo High GPS Navigator HP-33A /CE | eBay
The cheapest way to go is still the SDR USB dongle. I found a bunch of these at prices ranging from $5 to $15. I bought a Terratec a couple of years ago for $15. It's replacement is available for $12.80.
US Ship RTL-SDR Radio USB Kit for Terratec DVB-T TV FM add DAB RTL2832U Replace | eBay
My experience with the SDR device was similar to my experience with the dAISy--my antenna
wasn't good enough. SDR requires collecting some software
and configuring it to work
together. I went through all the steps and managed to get AIS targets to appear on my OpenCPN
display (when I connected my masthead VHF radio
antenna), so I know it can be made to work
. I don't know how much the SDR software
impacts OpenCPN's performance. I prefer to offload all that digital signal processing to the dAISy and make it a plug
and play appliance. If you don't mind tinkering SDR can save a few bucks and there's plenty of guidance on the Web to get you up and running.
It looks like the market is beginning to make AIS a pretty affordable option. OpenCPN's support for AIS lets you get by with a cheaper receiver that doesn't have its own display. It also assures you will be able to adapt to any changes in standards. You won't have to worry about your AIS equipment
becoming obsolete as you do with expensive proprietary units.