Selecting a new VHF: connected or stand-alone?

[Quebramar]

I have to replace my VHF and am not sure what would be best: connected to STNG network or stand-alone?
My plotter is an Axiom connected through STNG to a separate AIS with own GPS, the current AP from Ray as well as the old ST60 sensors (ST1 converted to STNG).
I am thinking of buying a Standard Horizon VHF, either GX1400G or GX1850G. They have same specs but the latter provides also NMEA2K which could connect to STNG backbone. Since both models have a GPS, the connection to the plotter is not per se necessary. I am trying to figure out the plusses and minuses of connecting…
Connected: redundancy of GPS input to plotter in case the AIS fails
Not connected: VHF as safety instrument not influenced by data from other equipment (could multiple GPS data sources create confusion in the VHF’s or the plotter’s mind…?), cheaper/simpler solution
What do you experienced sailors think about it?

[tkeithlu]

My vote is that you keep it separate, but then I feel that way about radar, chartplotter, AIS and the like because glass cockpits are very vulnerable to a system failure such as the monitor going ping. You should feed GPS into your VHF, so it will report location in an emergency, but beyond that I favor even running it off a separate small battery, because your house batteries are down low where they will be the first to go when the water gets on the wrong side of the fiberglass.

[dksail]

I have the same equipment you do and we are also keeping an eye out for a new VHF. At this point, I can’t see a reason to connect multiple GPS signals. You get signals from so many devices these days so for that feature, no.

However, would somebody create an app that will allow your MFD to use use more data from your VHF someday using NMEA2000? For example, automatically plot DSC coordinates from a call or relay?

I think the better value of the 1850 is the possibility of a remote, depending on your needs.

I would want to be able to turn off the unit’s GPS in the event of conflicts. I am interested in more comments.

[Quebramar]

Thank you both. Originally I was looking for connecting VHF and plotter for potentially being able to call an AIS target directly from the plotter… how cool in the English Channel! I searched quite a bit and realised this feature is more to be found in upper range models or even professional ones. Not for me.
2nd mike at the helm would be great, since I plan to keep the VHF at the chart table down below. But man, 1850 with mike is more than twice the price of the 1400 (550€ vs 220€) for the same technical specs… my portable vhf in the cockpit could continue doing the job in case of immediate need

[goboatingnow]

Originally Posted by tkeithlu

My vote is that you keep it separate, but then I feel that way about radar, chartplotter, AIS and the like because glass cockpits are very vulnerable to a system failure such as the monitor going ping. You should feed GPS into your VHF, so it will report location in an emergency, but beyond that I favor even running it off a separate small battery, because your house batteries are down low where they will be the first to go when the water gets on the wrong side of the fiberglass.

Class D gps needs an internal gps anyway. These days almost everything has a standalone gps function cause it’s so cheap to integrate

The old arguments about system wide failures are generally moot these days

My mfd , vhf, AiS all have independent gps functionality even though all are networked together

If you can go and the budget suits go with integrated

As for calling up ships in the English Channel , Ha ha.

[wholybee]

Connect to NMEA/stng with the later model. The lesser model would still need connected to your network, but with an extra cost converter, making it the more expensive option. Connection is required to get GPS into it which is required to enable DSC.

I also suggest also getting a better VHF that supports AIS. This lets you call a radio just by selecting its name from the VHF radio screen, via DSC. That is a very useful feature, to never have to hail "Vessel of my port side" type nonsense.

[Tugwit]

Well, I guess I’d come down on the side of connecting the VHF to the other, existing, instruments (MFD, GNSS, and AIS) in an NMEA 2000 network. Two benefits:

1. · Position of incoming DSC calls would be plotted on the chartplotter (assuming the MFD supports it), facilitating navigation to the reported position, and
2. · Able to conveniently initiate DSC calls to AIS targets (assuming the VHF supports it).

The first benefit requires connecting the VHF to the network (or at least to the MFD); the second benefit simply requires the VHF to have an internal AIS receiver (or to be connected to an AIS receiver or transceiver on the network).

But if your network already has a GPS receiver and an AIS device, an inexpensive VHF such as the SH GX2000 can provide these benefits without paying for a redundant internal GPS and AIS. And the NMEA 2000 network cabling and infrastructure is pretty robust and bulletproof, assuming a decent installation--which mitigates the reliability concern. Certainly much more so than NMEA 0183.

Quote:
“…(could multiple GPS data sources create confusion in the VHF’s or the plotter’s mind…?)…”.
”…My mfd , vhf, AiS all have independent gps functionality even though all are networked together….”

Most modern networks have multiple GPS sources, typically with varying accuracy. Devices in your network should have some method of manually prioritizing these different sources so that the preferred, most accurate instrument data is used by other instruments and displays that receive the data (typically of the same manufacturer). For example, in my B&G MFD is a “Settings-->Network-->Sources-->Position” dialog that is used to select the preferred GNSS data source where multiple sources exist.

Quote: `
“…would somebody create an app that will allow your MFD to use more data from your VHF someday using NMEA2000? For example, automatically plot DSC coordinates from a call or relay?...”

No app needed—provided your make & model of MFD supports receiving DSC call data from the VHF—either as NMEA 0183 DSC/DSE messages or as NMEA 2000 PGN 129808-DSC Call Info.

For example, my venerable SH GX2150 VHF sends a DSC/DSE message pair upon receipt of a DSC call (e.g. a DSC Position report) from another vessel. The VHF is connected to my B&G MFD and to a PC running OpenCPN, and both devices plot the position of the calling vessel on their chart. The DSC call info also appears in the AIS target list on the MFD and in OCPN.

Quote:
“….Originally I was looking for connecting VHF and plotter for potentially being able to call an AIS target directly from the plotter…”

This appears possible only by using a proprietary PGN supported by an MFD and VHF from the same vendor. AFAIK there is no standard, vendor-independent PGN that would provide multi-vendor interoperability, unfortunately.

That said, if the VHF has a built-in AIS receiver, or can connect to an external AIS like the SH GX2000, then you can quickly initiate a call to an AIS target using the radio’s interface with no need to enter the MMSI number of the target. Not as simple, perhaps, as poking a finger at your MFD’s touchscreen, but since you’ve got to have to get the VHF mike in your hand anyway to talk to your target, not that much more inconvenient.

[Quebramar]

Many thanks for these detailed thoughts, much appreciated. I’ll go for the 1850 (also called Explorer) as it will provide connectivity and thus redundancy of GPS in case the AIS fails, and N2K is definitely a better option indeed. It also allows future acquisition of a remote mike if this would make sense.
Thanks again, this helped me clarify.