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carlylelk · 27-10-2018, 12:23

I'm trying to hook up a GPS antenna to the ICOM M802 port. The ICOM female is not the typical threaded connector, it's a twist-lock type.

Can someone tell me what it's called so I can find one?

It used to be hooked up to an old Furuno chartplotter so I have the old connector but it does not look to be reusable.

Thanks!
Duane

nhschneider · 27-10-2018, 12:26

It uses a BNC connector which can be either twist-on, which are reusable or a crimp on, which are not reusable.

Good luck.

carlylelk · 27-10-2018, 12:56

Does the BNC connector come in different sizes?

ka4wja · 27-10-2018, 15:00

Duane,
The M-802 "GPS" input is a NMEA0183 data INPUT....for GPS position data....
Yes, it is a BNC-female connector (no, they are all the same size), so many think all they need to do is connect a "GPS antenna", but there is no GPS receiver inside the M-802, so you must connect the M-802's "GPS input" to a GPS unit (receiver) that outputs NMEA0183 position data....

Quote:

Originally Posted by carlylelk

I'm trying to hook up a GPS antenna to the ICOM M802 port. The ICOM female is not the typical threaded connector, it's a twist-lock type.

Can someone tell me what it's called so I can find one?

It used to be hooked up to an old Furuno chartplotter so I have the old connector but it does not look to be reusable.

Thanks!
Duane

Most consumer marine "GPS antennas" these days are in fact entire GPS receivers (without display of course) that output GPS position, speed, etc. data directly on their wiring....usually in NMEA format, although Raymarine units output either NMEA or "SeaTalk" (or "SeaTalkNG" / NMEA2000)

If you have an "old GPS antenna" from an old Furuno Chartplotter, you need to determine if it is in fact a "GPS antenna" (antenna only), or a "GPS receiver" that looks like an antenna??

OR...

Or, you can simply do what 1000's of other Icom M-802 owners do, and that is to use a dedicated GPS receiver (such as an inexpensive Garmin GPS76, or any GPS "puck", etc., that outputs NMEA0183 data)....and connect that to your M-802...

As for the BNC connector on the M-802...yep, it is odd that they use that, but it is simple, idiot-proof and vibration / weather protected....so, all you need is a BNC cable of any kind (I use commercial video cable, w/ BNC connector on it) and connect it to the M-802 and the other end (wires) to NMEA0183 GPS position data...
And, you're all done...

Dockside Radio includes this cable, as well as instructions in all of this, with every M-802 purchase...
But, assuming you didn't buy your M-802 from him....You can still buy the cable from Gary at Dockside Radio for $25....
Icom SSB Radio Kits & Components

If you look at the stickies at the top of this page you'll many references there that will answer your questions...
http://www.cruisersforum.com/forums/...tc-198305.html

http://www.cruisersforum.com/forums/...tc-133496.html

fair winds.

John

P.S.
Also, have a look at these YouTube Playlists...

Icom M-802 Instyruction Videos
https://www.youtube.com/playlist?lis...rC-8QKVyMb4tVr

HF-DSC
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX

Maritime HF Comms
https://www.youtube.com/playlist?lis...ZDo_Jk3NB_Bt1y

Offshore Weather
https://www.youtube.com/playlist?lis...zdjTJjHlChruyY

Offshore Sailing
https://www.youtube.com/playlist?lis...KgTCj15iyl6qoY

CarinaPDX · 27-10-2018, 16:24

The BNC connection should be NMEA 3.01 (according to the manual), which is an RS-422 TTL protocol. Most GPS pucks that have a serial (non-USB) output will be compatible. Do be careful with the Garmin brand as they used their own incompatible protocol for a long time.

You will also need a power supply for the GPS, which will usually be 5VDC. Good, inexpensive DC-DC converters are readily available, and in a pinch you can take apart a cigarette lighter USB charger and use the output of that for 5V. I use this one for about $2 from China, shipping included: https://www.aliexpress.com/item/OUTA...854223982.html

There is no need to spend a lot on a GPS puck. I am using GlobalSat M-350 mushroom-shaped units, with standard 1"-14 threaded mount. I don't recommend them now as they use the old SirfStar III GPS modules, although they work just fine (and better than the SirfStar IV modules). Also, there are lower-cost, faster, and slightly more accurate modules available. I recommend a navigation-grade uBlox Neo8 module, which is capable of receiving all four GNSSes (GPS, GLONASS, BeiDu, and Galileo) plus various regional augmentation systems. N.B.: It is only able to use 3 at a time, so program out GLONASS (inaccurate) and in Galileo (very accurate). An example of such a unit, at $30 delivered from China: https://www.aliexpress.com/item/New-...850230790.html If you are looking for alternatives, be certain they have flash included and support Galileo.

Greg

**a64pilot** · 27-10-2018, 17:58

It’s NMEA 0183 data, which means simple two wire connection.
I connected both my VHF and my HF to my Vesper WatchMate.
I could I believe have also connected to my Zeus plotter.
Most of us have something that outputs positional data over NMEA 0183.

However if you don’t also have a separate DSC antenna connected to the 802, and I don’t think most do as I’ve looked on other boats and not seen one, inputting positional data to an 802 isn’t going to do any good, is it?

The Dockside cable is a little over priced, but it the simplest answer.

**Wotname** · 27-10-2018, 19:06

Quote:

Originally Posted by carlylelk

Does the BNC connector come in different sizes?

Yes and no...

They are all the same size regarding the mating aspects but there are different sizes regarding the cabling aspects.

So all BNC connectors will mate (and work) with their respective gender opposites but you can get BNC connectors for different cable sizes. RG178, RG58, RG8 etc all have different diameters ad you can BNC connectors to suit each.

In your application (M802 GPS connection), any cable will do.

**Wotname** · 27-10-2018, 19:10

FWIW, your GPS positional data (Lat / Lon) will be displayed on the 802 control head even if you don't have a DSC antenna etc. once you have inputed it into the Tx/Rx.

ka4wja · 27-10-2018, 19:13

You can use just about any GPS receiver...even Garmin...

(out of the box, many Garmin's default to output their own data, but easily switch to NMEA)

Unfortunately, many modern cruising boats are set-up to use a GPS chartplotter...their GPS receiver is typically wired to the chartplotter, as this is many times the only position display....often this is the power source for the GPS as well....
That means you have no GPS position data without the plotter...

Some, also have AIS transponders....and AIS transponders are required to have their own GPS position data, from their own (built-in) GPS, whether using an external antenna or in-built one...
Many will use their AIS transponder's GPS position data for the DSC radios...
But, fyi...some AIS transponders output NMEA in only one mode (such as NMEA0183 38.4kb, for displaying AIS target data) and you may be limited to what NMEA data you can take out of the transponder, so some AIS transponders will not output NMEA0183 at 4.8kb (for position data to DSC Radios) and 38.4kb (for AIS target display) at the same time??
(or course Vesper is tops, and can do it all....just wanted everyone to understand that all AIS units are not the same..)

Also, many newer electronics packages are networked using NMEA2000....and unless you want to use a NMEA2000 to NMEA0183 converter....and leave your main GPS, and NMEA2000 backbone, powered up all the time, just to send your position data to your M-802, you'd again have no position data to the M-802...

Further, having a separate / dedicated GPS for your DSC radios, allows you to always have position data to the radios, and displayed for you 24/7....and if you have it directly wired (and/or have separate internal batteries, in the GPS...as in a Garmin GPS76, etc.) this allows you to always have position data on-board and delivered to your DSC Radios, 24/7, even if your breaker panel / 12vdc distribution / battery switch system has failed (your M-802 is wired directly to the batteries, with its own fuse..yes???), you can still use your M-802 and send a DSC message, such as a DSC Distress Call...

There are other reasons to have a separate / dedicated GPS for your DSC radios, but these are the top few...

~~~~~~~~

Now, as for how to use the DSC functions of the M-802....they are detailed in the videos, quite well...
Please have a look...
But, specifically to this point here...

Quote:

Originally Posted by a64pilot

However if you don’t also have a separate DSC antenna connected to the 802, and I don’t think most do as I’ve looked on other boats and not seen one, inputting positional data to an 802 isn’t going to do any good, is it?

The "DSC Antenna" that you write about, is the DSC Receive antenna that is directly connected to the built-in six-channel scanning, dedicated DSC receiver, inside the M-802....and this operates in the background, all the time the radio is switched on, no matter what band/freq/mode the M-802's main unit is doing...
This is not a transmit antenna, but a receive-only antenna connection...

This separate DSC receive antenna is not required to send a DSC call/message.

But, of course, is required to receive DSC "Safety", "Urgency". or "Distress" messages!

And, of course is required to receive an ACK (acknowledgement / reply) to your own DSC "Safety", "Urgency", or "Distress" call that you sent!

Fyi, no DSC radio will transmit / send a DSC message, unless the radio has a valid MMSI# programmed into it!!
So...
So, PLEASE obtain your MMSI# from your country's radio authority (in the US, this is the FCC....and the MMSI# is included with your FCC Ship's Station License, which you must have anyway, in order to have the M-802...so, everyone with an MF/HF-DSC-SSB Radio should already have their MMSI#...)

Further, without position data input to the radio, you'd have to manually input your position....and who here thinks they'll be able to accurately type their exact present position into the radio, using its keypad, while they're fight a fire, or trying to plug a hole in their hull, or dealing with a major medical issue/injury??
SO...
So, PLEASE connect a GPS to your M-802 and to your VHF-DSC radio as well!!

Have a look here at this Youtube Playlist...

HF-DSC Comms
https://www.youtube.com/playlist?lis...ga2zYuPozhUXZX

Hope this helps...

John

ka4wja · 27-10-2018, 19:19

To clear things up here...
This is getting WAY over thought...

1) You need a GPS receiver that can input its NMEA0183 data into the M-802...(whether you buy a pre-made cable, use a BNC adapter, or make up your own cable....you need to have NMEA0183 position data connected to this BNC female connector on the M-802, labeled "GPS" data in..)

2) You need a valid MMSI# programmed into the M-802...

3) You should have a separate DSC receive antenna connected to the M-802...

All of this is well explained in the M-802 manual, albeit it's worded in a complicated way...

Further, this is explained in the videos and in some of the stickies above..

Fair winds.

John

CarinaPDX · 28-10-2018, 03:51

I have three separate GPS sources for the installed gear: the one included with the AIS, an MR-350 attached to the chartplotter, and another MR-350 attached to the communications gear (M-802, DSC VHF, and modem). At about $32 each (see earlier post) it is well worth having the redundancy and cut down on the cable runs. Also, there are limits as to how many listeners can be on one talker (usually 4). Of course I have a USB GPS puck for the laptop, and both the tablet and phone have GPS as well as 3-dimensional orientation and accellerometers. In one sense I have a ton of redundancy, but all the eggs are in the GPS basket except for the USB puck, which supports all 4 GNSSes. I think that is a good argument for updating to the newer modules.

I didn't have, but now do, a separate DSC receive antenna. On a small boat it is a bit of a marginal expenditure as the M-802 is too high a load to comfortably leave on standby 24/7.

Greg

carlylelk · 28-10-2018, 10:38

John,
Thank you for the information! I have watched all of your videos on the ICOM recently, and that's what motivated me to work on the ICOM GPS connection. The radio came with the boat when I bought it but the Furuno chartplotter it was connected to for GPS was not working. It does have it's own DSC antenna, and I do have the MMSI # programmed into it. I also had the software updated and bench-checked after the boat purchase.

As it happens I have a GPS76 that I keep as a backup. I like the idea of having the GPS data for the ICOM separate from the NMEA2000 system (that I recently installed, so I do have some skills ;-).

Would you do me the favor of explaining how you hooked it up to 12V power and to the ICOM? I have a chord for the GPS76 intended to connect to the computer thru a USB connection. I'm guessing there is a pin-out list that I could use to convert this chord to provide power and NMEA data connection? ...or do you use batteries to power it?

I was surprised that it would get enough satellites in the boat since in my previous life it would not within a building. Did you connect it to an external antenna?

Thanks,
Duane

ka4wja · 28-10-2018, 17:02

1) First off, please excuse me for not being politically correct.

When I write "GPS" I am of course referring to GNSS...but please if we could not split hairs here, as this just confuses the issue at hand...

Although in all honesty, if a particular GNSS receiver only receives GPS signals, that's okay with me on-board my boat...I mean how accurate of a satellite fix do I need? If for some reason I loose a 3D multi-sat fix, and find myself doing a running DR fix for a bit, I'll survive just fine...(heck, I used celestial nav on my first Atlantic crossing decades ago...and the best fix I've ever gotten with my sextant is about 2 miles off...)

~~~~~~~~~

2) Duane, you're welcome!

3) Okay, now onto the actual question...
A couple years ago I "upgraded" to new GPSMAP76's and GPSMAP76Cs...
{I have 3 of them on-board....one mounted at Nav Station for DSC Radios (along with my new Icom M-93D handheld vhf); one in ditch bag with another handheld vhf; and one in locker next to Nav Station with another handheld vhf (for use in my dinghy)...
I know, probably a waste for most of you....but I believe in redundancy, and enjoy easy / plug-n-play (idiot-proof) redundancy....and the fact that I still have a old GPS76 at home that works fine, and still is water-tight as it was 15 years ago....how many will be able to say the same about their GPS pucks in 15 years??

a) Duane, please make sure you select "NMEA4800" for the data output from the Garmin, as I think their default is their own GarmiNet??
Anyway, if you have it set for NMEA4800, it will provide you with position data for your DSC radios...
(btw, before installing an AIS transponder, I had an AIS receiver since 2006, and used the Garmin76 to provide position data to the AIS receiver as well as Icom M-802 and Icom M-602....but, now it just sends NMEA to the M-802 and M-602, as I have an AIS transponder with its own GPS....and also have Raymarine Raystar125 GPS for my ST-80, E-120, E-80, ST-6002+, ST-60+...all weather-proof and working well...)

Quote:

Originally Posted by carlylelk

As it happens I have a GPS76 that I keep as a backup. I like the idea of having the GPS data for the ICOM separate from the NMEA2000 system (that I recently installed, so I do have some skills ;-).

Would you do me the favor of explaining how you hooked it up to 12V power and to the ICOM? I have a chord for the GPS76 intended to connect to the computer thru a USB connection. I'm guessing there is a pin-out list that I could use to convert this chord to provide power and NMEA data connection? ...or do you use batteries to power it?

I was surprised that it would get enough satellites in the boat since in my previous life it would not within a building. Did you connect it to an external antenna?

Thanks,
Duane

b) I use a Gamin "power and data cable" (cost me about $19)....
12vdc ships power in, and NMEA 4800 data out...
https://www.thegpsstore.com/Garmin-p...able-P545.aspx
(I also install 2 AA batteries into the GPS 76's and GPSMAP76's, when heading off, there by giving me GPS position even if ships power is lost..)

c) I also use a Garmin Marine Mount, to securely mount my Garmin units to the Nav Station...(cost me about $25)
https://www.thegpsstore.com/Garmin-m...ries-P419.aspx

d) I regularly get 6 or more satellite fixes, with the Garmin 76 series units inside the cabin...even with a wet deck, and in heavy weather...no issues at all...
But, this is a fiberglass boat and deck....alum or steel boats will need ext antennas...

Have a look:

Hope this helps...

Fair winds...

John

Russ · 14-10-2019, 13:31

I have Globalstar BU 353 S4 receiver connected to my new ICOM 802 but I can't get a lat/long feed to the 802 via a Dockside Radio BNC coax connection.
I have a feed to my chart plotter ( laptop running The CAP'N) but despite many different attempts and hook up variations I have no position data on the ICOM radio itself.
Any suggestions Please
Thanks Russ