Cheap as possible Nav-with-AIS setup

[Sir_Crabs_A_Lot]

I'm attempting to build a Cheap as possible Nav-with-AIS setup. I'm posting fresh here because the thread "Class B AIS waste of money" is closed.

I have a 7.5m steamboat that I use on Puget Sound. Recently I went airborne off a wake from a planing megayacht that appeared suddenly from around a point. I feel having a CPA alarm would be helpful. I need to see other ships but don't need to be seen myself as I'm aluminum and steel and have a huge radar signature.

Anyway.... Here's my setup so far: I have a 15" Lenovo laptop with Windows 10 running OpenCPN, getting a feed from a GlobalSat BU-353 S4 "puck" receiver (NMEA 0183) in one USB port, and a wireless mouse in another USB port.

Now I'm shopping for a VHF. I need a NMEA 0183 unit because I don't want to stick a 0183 to 2000 translater in the mix. I already know I don't need a "Class A" unit. I see units with DSC described as "Class D", and units described as "Class B", some with GPS and some with GPS/AIS capability, each step getting more expensive. I like Standard Horizon or Icom units.

HERE'S MY QUESTION(S):
Does OpenCPN process AIS sentences from the VHF unit within its own program?
I already have a GPS so getting a unit with GPS is a waste of money, right?
Since the AIS signals are coming over channels 87 and 88, will any VHF unit do?

Thanks,
Ryan

[nohal]

You should understand a few things first:
* There are only two AIS classes, A and B. B for leisure craft and A for commercial, big, fast ships. B is much cheaper. B transmits at much lower power. B transmits with much lower frequency. (https://navcen.uscg.gov/?pageName=typesAIS) For receivers it does not matter at all. If you want a transponder, you want class B.
* There is a very big price difference between an AIS transponder and receiver. While a receiver may be had from USD50, the transponder costs hundreds. The transponder also must have it's own dedicated GPS.
* AIS transmits on VHF frequencies, but you can't connect your marine VHF radio to a computers sound card and let some program decode the data. There are marine VHF radios with integrated AIS receiver though. These have a serial or USB output which you can connect to the computer.

If you want to stay cheap and receive only (with OpenCPN or similar always running on a computer), you want https://www.tindie.com/products/astu...-ais-receiver/

If you are going to invest into a marine VHF radio anyway, you want Welcome to StandardHorizon.com or something similar

If you also want to transmit your own position to others, you want to be looking at these: https://www.westmarine.com/ais-transponders-antennas

If you are an adventurous technician, you want https://www.ebay.com/itm/1CA2-USB-Do...8AAOSw4gpbcnTP and time.

[Reefmagnet]

A cheap USB SDR receiver can be jigged as an AIS receiver with a bit of free software and tweaking. If you have an AIS receiver with nmea 0183 output already (or are determined to use one) you just need a cheap USB RS422 adaptor (some will say an RS232 adaptor is fine for this purpose, and it probably is, but RS422 is the NMEA 0183 transmission protocol). Open CPN will interpret AIS nmea sentences. Remember that the data speed for AIS is 34800, not the "normal" nmea 0183 4800 bps speed, so this connection would be dedicated to AIS reception which is no problem because OpenCPN can simultaneously receive NMEA 0183 data over multiple ports (and relay too!)

[GILow]

Cheap is relative but in terms for bang-for-your-buck I am very happy with the Matsutec HP-33A Class B AIS transponder I bought recently.

It has NMEA input and output so it is flexible plus it’s a decent little GPS gadget as well.

Early days yet but I am growing to really like it.

[RaymondR]

I used a fairly cheap (As AIS stuff goes) GME AISR120 receiver with it's own antenna to feed an RS422 to USB converter into my small 10" nav computer running OpenCPN on my last boat. From memory the whole setup to include AIS cost less than A$400.

If I set this boat up for AIS I will probably include a transceiver this time as whilst it is more expensive it seems a little more courteous to let others know who and where one is and are if you wish to receive the benefits of the system - mutual obligation thing (and before you bust into print I am aware that mutual obligations is an obsolete pre-boomer concept but then so am I)

[Sir_Crabs_A_Lot]

Thank you, all, for your replies.

RaymondR, that setup is too expensive for me. Reefmagnet, my laptop has no serial port so that's out. The Matsutec HP-33A is too pricey and duplicates some of what I have.

Nohal, YOU NAILED IT! The dAISy AIS receiver is just what I was looking for. Inexpensive, has a USB port, perfect!

[Reefmagnet]

Originally Posted by Sir_Crabs_A_Lot

Thank you, all, for your replies.

RaymondR, that setup is too expensive for me. Reefmagnet, my laptop has no serial port so that's out. The Matsutec HP-33A is too pricey and duplicates some of what I have.

Nohal, YOU NAILED IT! The dAISy AIS receiver is just what I was looking for. Inexpensive, has a USB port, perfect!

Just to clarify, the adaptors plug into the USB port on a computer. They adapt the serial output of an NMEA 0183 device to USB. The driver on your computer then takes the data from the adapter connected to the USB port and presents (virtualises) it as a standard COM port to software running on the PC. The PC itself does not need to have a physical serial port.

[skipperearly]

there is also this option : https://seaangel.at/index.php?language=en
works great for me and can also send AIS/NMEA signals via Wifi.
So iPad with e.g. iNavX can display AIS or Android device with OpenCPN or PC - all concurrently !

[pa36651]

I have used Nasamarines AIS receiver with a DYI antenna together with opencpn since 2010 w/o problems. With the antenna on the push pit it show all AIS ships at a range of approx 10nm.
https://www.nasamarine.com/product/ais-engine-3/

Slimjim DYI vhf antenna
http://orebrohamn.com/ais/slimjim.htm

[rgleason]

OpenCPN Supplementary Hardware > AIS

[Sailmon]

We’ve been very happy with our Standard Horizon GX2200 VHF. Only drawback for us - it puts out NMEA0183 - which we needed to convert to NMEA2000 to work with our Raymarine MFD. Sounds like you are looking for 0183, so would be good match.

[barnakiel]

I have a SH unit plugged into plenty of devices, wired and wireless. All works great also OpenCPN.


Saying Class B is useless was plainly stupid and irresponsible. Good news that thread is shut.


Our SH is receiver only, but now there is a SH transceiver too. Just a bit expensivish (only if considered AIS alone).


b.

[Sir_Crabs_A_Lot]

Originally Posted by rgleason

OpenCPN Supplementary Hardware > AIS

How did I miss this reference? I knew about the Vesper already but considered it too pricey. The dAISy seems the way to go, for me anyway. Thank you so much!

[RaymondR]

If you want to go real cheap you can hack an old VHF radio to extract the AIS sentences and feed them into the sound card for processing with a bit of code.

[fgd3]

I tried the dAISy and found I needed a dedicated VHF antenna for it. I mounted the antenna on a bulkhead below decks. AIS range is about 20 miles. I don't see the need to know about vessels farther away than that. Search eBay or Amazon for a cheap antenna, 4' whip, for around $20. I think you'll need an adapter to make the antenna fit the dAISy, if I remember right. By unplugging the dAISy you can use the antenna as an emergency spare for your VHF radio, but the below deck mounting I used will reduce range quite a bit.


Fabbian