AIS VHF SSB and a Pi, Oh my!

[NorthernMac]

Evening guys.

I just ordered a Simrad RS40-B (VHF Radio w/Class B AIS transceiver & Internal GPS), it getting installed on my cutter that will be running OpenCPN.

I'd like it to feed AIS data to pi (with the new moitessier hat on it), is this possible?

Also should I run a new cable and antenna on the boat from the older VHF it has?
Would one antenna be able to be spliced for VHF, AIS on the simrad and maybe SSB with a usb radio for the Pi?


THANKS!!

[Dsanduril]

For the first part, easy, the RS40-B had NMEA 0183 at 38400 baud and will send the AIS data to the PI.

The 40-B requires two antennas, one for the VHF function and one for the AIS transmit function, or one antenna and a splitter (sold separately).

For the USB I'd recommend a separate random wire antenna, VHF antennas aren't very good for SSB reception and you'd have to have a switch to take it offline when transmitting to prevent burning out the receiver (and the AIS transmits pretty frequently).

[NorthernMac]

Originally Posted by Dsanduril

For the first part, easy, the RS40-B had NMEA 0183 at 38400 baud and will send the AIS data to the PI.

The 40-B requires two antennas, one for the VHF function and one for the AIS transmit function, or one antenna and a splitter (sold separately).

For the USB I'd recommend a separate random wire antenna, VHF antennas aren't very good for SSB reception and you'd have to have a switch to take it offline when transmitting to prevent burning out the receiver (and the AIS transmits pretty frequently).

Ok!

So I could get away with two antennas

One for VHF/AIS

One for SSB

Do you have any recommendations for mounting, ideally low profile

And what antennas and cable?

Thanks again

[Dsanduril]

For the VHF/AIS height is your friend, so not sure about "low profile". Usually a quarter- or half-wave antenna somewhere on the mast/spreaders. Don't have any specific recommendations, I go to the local stores to see what is available.

Be aware, you'll need an "active" splitter - one that disconnects the VHF when the AIS is transmitting and vice versa. A passive splitter is just a tee, and the transmitted power from one device will go into the receive section of the other device and break things.

For the SSB, receiving, any random length wire, unless you use a single specific frequency/channel is fine. You can run it indoors, behind cabinets and cushions, or outdoors along the lifelines (we have Dyneema lifelines and inserted a wire as a receive antenna as a "core" in one of the lines - works pretty well and it's hidden).

[pcmm]

Originally Posted by NorthernMac

Evening guys.

I just ordered a Simrad RS40-B (VHF Radio w/Class B AIS transceiver & Internal GPS), it getting installed on my cutter that will be running OpenCPN.

I'd like it to feed AIS data to pi (with the new moitessier hat on it), is this possible?

Also should I run a new cable and antenna on the boat from the older VHF it has?
Would one antenna be able to be spliced for VHF, AIS on the simrad and maybe SSB with a usb radio for the Pi?


THANKS!!

Feeding the data to a raspberry pi is easy, you just need a RS485->USB adapter board. You don't even need the Moitessier hat as you're getting both AIS and GPS from the VHF device. You can get those boards off ebay for under $10 and either keep the hat as a redundancy or sell it on!

[NorthernMac]

Originally Posted by Dsanduril

For the VHF/AIS height is your friend, so not sure about "low profile". Usually a quarter- or half-wave antenna somewhere on the mast/spreaders. Don't have any specific recommendations, I go to the local stores to see what is available.

Be aware, you'll need an "active" splitter - one that disconnects the VHF when the AIS is transmitting and vice versa. A passive splitter is just a tee, and the transmitted power from one device will go into the receive section of the other device and break things.

For the SSB, receiving, any random length wire, unless you use a single specific frequency/channel is fine. You can run it indoors, behind cabinets and cushions, or outdoors along the lifelines (we have Dyneema lifelines and inserted a wire as a receive antenna as a "core" in one of the lines - works pretty well and it's hidden).

So I’ll run the wire on the inside of the hull for SSB for the Pis SDR, that’s easy enough.

Any recommend for the splitter?

I was also going to just use he antenna on the mast for the VHF/AIS

[Dsanduril]

I use the Vesper one, but only because it came as a package with my AIS. On its own it seems expensive.

Raymarine make one, and so do nearly every other AIS manufacturer. Simrad makes at least one, might want to see if the place you got your radio would honor a package price. I don't know of anything particular that would cause me to recommend one over another.

My personal preference is two antennas, one at the masthead and one at the spreader, but I still haven't gotten there myself and just use the VHF antenna at the masthead. works fine. One caveat, if you yak a lot on the VHF while underway you'll be preventing your AIS from doing its job. I only use the VHF for minimal conversation, so it is dedicated to AIS and VHF reception 99.9% of the time.