GPS Chart Plotters VHF Radios

[MarkSF]

Just paid $109 for a Standard Horizon GX1150 VHF with DSC+. The old radio had very noisy volume and squelch pots.

For the GPS, I've had the Garmin 72H with the basic database, and now the 78SC with bluechart built in. The new one is pretty powerful with the full chart. The main limitation is with the tiny screen. If you have it zoomed in enough to see buoys and depths, you can't see where you are.

For the $400 it cost you can get a much-larger screen built-in model.

Whichever you get I would strongly recommend the full pre-loaded charts - just so much more useful than the basic database.

[CaptKermie]

Personally I am not a big fan of hand held VHF radios unless they are part of the fixed unit ie. WHAM mic where you harness the 25 watt power of the fixed unit.
Hand held VHFs are usually 1 watt low and 5-6 watt high power ratings and I really don't have a lot of faith in those rubber ducky antennas they have, not the greatest transmitters. Some of my sailing freinds make do with them but I still recommend to them that they invest in a fixed mount system that runs off the 12 volt battery. The fixed units generally have a 5 watt low and 25 watt high power rating and at the high power can transmitt a Mayday call considerably further and stronger, assuring a greater chance of being received by the Coast Guard. I have both and I only use the handheld when in close range such as a regatta or marina call where I am already within close proximity. I rely moreso on my fixed mount with masthead antenna for more important communications. Just my take on it.
I do also use a hand held Garmin 76CS with added in charts but it is now obsolete and I cannot even get updated bluecharts for it. Thanks Garmin folks.

[speedsquare]

I've read this other threads. I am trying to determine if I can connect a Handheld GPS (Garmin Map76 or simmilar) to DSC equipped fixed VHF? Does any one have any light to shed on this.

Back to the thread, I would not reccomend the e-Trex line for boating. They are great for land based excursions, but the Map 76 or 78 series is the way to go. Bigger screen, floats, waterproof, plotter function)

[Stu Jackson]

Brian, these replies were very helpful and detailed. Since you were in a West Marine store, I suggest you get one of their catalogs and read the West Marine Advisors, or you can read them online. They cover a lot of the basic information you're asking about.

[sailingfool]

Originally Posted by speedsquare

I've read this other threads. I am trying to determine if I can connect a Handheld GPS (Garmin Map76 or simmilar) to DSC equipped fixed VHF? Does any one have any light to shed on this.

The device spec says it supports NMEA out so theoretically yes if your VHF takes the same NMAE version, however even then I'd try to find someone with the same gear who had made it work before I'd make a purchase based on this. (I never got my last Garmin to work...)

That said, I would worry that in an emergency, getting the handlheld GPS connected and synched to the VHF may be a dicey proposition, I would not count that circumstances would permit that. Especially if the obligation of pushing the DSC button falls to a significant other.

[mherrcat]

You could check with your VHF manufacturer. As noted, in theory if the GPS unit has the correct NMEA output you should be able to do it; figuring out how may be another story.

I am about to install a Standard Horizon GX2150 fixed mount VHF with a remote mic installed in the cockpit. Since I don't have a chartplotter I am also installing a GPS antenna/receiver that will connect to the VHF to provide coordinates for the DSC function. The VHF NMEA input/output is a bare wire, so SH recommended cutting the plug off the antenna cable and wiring it to the VHF via a terminal block. I am hoping to be able to make a mating plug/pigtail for the GPS plug and wire that to the terminal block so I don't have to cut the cable in case I need to connect it to a chartplotter at a later date.

[MSN2Travelers]

Picking up where this thread left off back in June …

I am electronically intimidated (fear hooking up the wrong two wires will let the magic smoke out.) The new-to-us boat came with `98/`99 vintage electronics at the nav station (ancient GPS and a radio that did not have DSC). The PO also bought a Garmin 192C at some point that he used at the helm.

Here is what I have –

Newly installed SH 2150 AIS VHF at the nav station with RAM at the wheel.
Garmin 192C moved to the nav station (I had a GPS chart plotter from the last boat that the Admiral liked and wanted at the helm.)

I want to connect the “itty bitty” wires on the Garmin to the “itty bitty” wires on the 2150 so the radio knows where we are for the DSC function. If the SH 2150 can also send data that allows AIS targets to display on the Garmin, that would be an added plus.

Here is what I know –

The Garmin has two “com ports” that can be individually set to speak Garmin, NMEA, Sonar or nothing. Com 2 can also be set to speak RTCM In/NMEA Out in addition to the “languages” listed for Com 1. The Garmin speaks NMEA 0183 version 2.3 and RTCM SC-104. It appears that the Garmin talks at 4800 bd on both com ports.

Garmin Wires:
RED – Unit Power
BLACK – Unit and Data Ground
BLUE – NMEA OUT (Com 1 TX)
BROWN – NMEA IN (Com 1 RX)
WHITE – RTCM or NMEA IN (Com 2 RX)
GREEN – NMEA OUT (Com 2 TX)


The SH 2150 wires:
GREEN – NMEA Ground
BLUE – NMEA GPS Input (+)
GRAY – NMEA DSC Output (+)
BROWN – AIS DATA Output (+)

I’m guessing that I should connect the wires as follows:
SH2150 GREEN (NMEA Ground) to Garmin BLACK (unit & data ground)
SH2150 BLUE (NMEA GPS Input) to Garmin BLUE (NMEA Out / Com 1 TX)
SH2150 GRAY (NMEA DSC Output) to Garmin BROWN (NMEA IN / Com 1 RX)
SH2150 BROWN (AIS DATA Output) to Garmin WHITE (RTCM/NMEA IN / Com 2 RX)

Configure the two Garmin com ports to speak NMEA IN / NMEA OUT at 4800 bd.
Configure the SH2150 to talk at 4800 (the manual says the SH2150 BROWN wire will always talk at 38400 bd even if the other channels are set to 4800 bd.

Does this look like it should work?

[TakeFive]

You can try it, but I doubt it will work for AIS. The reason the GX2150 brown wire always talks at 38400 is the AIS data would overload a 4800 baud connection. If you can't get the Garmin to receive 38400, you might not be able to send the AIS data to it.

Note that the GX2150 has two modes - send both DSC and AIS on the same wire, or split the two over two separate wires. Make sure you have the correct setting - I think the default is both on the same wire.

Also, sending your GPS data to the radio is critical. In addition to enabling DSC as you mentioned, it helps prioritize your AIS targets (closest ones at the top of the list). It also allows the radio's little radar display to position your boat at the right spot relative to the other AIS traffic, which will be especially important if you can't get it to display on your GPS.

Here's some info on my setup. Might be a little more than you want to know.

[hellosailor]

"I assume that the antenna on the mast is fine"
Actually, not. Antennas and antenna cables tend to take water damage, get stretched out, decay. If it is even 5 years old that's time to either test it or replace it and if you do, use premium cable properly secured and waterproofed.
I use a handlheld more often than the fixed radio, but a handheld can be dropped overboard, or on the deck, or run down the battery. A fixed radio just doesn't have those weaknesses. (Instead, it has the antenna-up-the-mast issues.)
If you do buy a handheld, either as your primary radio or backup, also buy a 12-volt power cord for it, so you can plug into the main battery power to recharge it. They're not expensive.

Chart plotting in LIS? Eh, you can usually rely on piloting in LIS, there are plenty of landmarks easily recognized. The bouys tend to be in the same place year after year, and there are lots of them, although of course some are pulled or disappear from time to time. I'd make the radio(s) the priority, and add a pair of 7x50 binocs with a compass in them, to make the piloting easier.

There's a lot of deep unobstructed water and well-marked channels, unless you plan to go rock-hopping LIS is pretty easy to navigate.

[TakeFive]

Originally Posted by hellosailor

"I assume that the antenna on the mast is fine"
Actually, not. Antennas and antenna cables tend to take water damage, get stretched out, decay. If it is even 5 years old that's time to either test it or replace it and if you do, use premium cable properly secured and waterproofed...

Short of testing the radio/antenna combination, is there a way to test just the antenna and cable?