Can a GPS Antennae fail?

[txh2oskier]

I have a Raymarine C60 Chartplotter with an external (brand unknown) GPS antennae. Whilst sailing this past weekend the chartplotter lost its fix. Several cycles of power off and back on hasn't resolved it. Is it possible the antennae itself has failed or is it more likely a connection failure?

I'll be back at the boat tomorrow and would appreciate some tips on trouble shooting the problem.

Thanks.
Brian

[nigel1]

Short answer, is yes, the GPS antenna can fail.
I'm sure that the GPS antenna used with a c60 is both an antenna and GPS receiver, the fix is resolved at the antenna unit and the data transferred to the chart plotter.

I've not used a C60, is there anyway you can get it to display GPS satellite status, normally in the Setup menu, should be something like GPS Status or GPS set up.
This will allow you to see if number of sats tracked and the signal strength.
However, no harm in checking the connections, but best to turn off the power to the C60 when disconnecting the antenna.

[River Cruiser]

If you can borrow a display from someone and hook up to your antenna if you still have the same problem then it would be your antenna. Good luck


Sent from my iPad using Cruisers Sailing Forum

[Moody46CC]

I had a Raymarine mushroom-like GPS antenna fail. As I recall, the chartplotter could not get a fix on a signal. A technician said the unit (sealed) had a battery, so he replaced it with the up-to-date model. That unit worked fine and was working when I sold the boat. Sadly, I do not recall the model number of the failed antenna.

[rwidman]

Quite possibly the antenna can fail. It's more than just a passive antenna.

Just last week I happened to turn on my system and noticed that the display was not getting a position from the antenna. The MFD still sees the antenna and notices if I pull the fuse but no position. Strangely, an hour later I tried it and it worked. Yesterday it didn't work. I have a spare so I'll be swapping it out before I go anywhere.

[hellosailor]

If it is just an antenna, unlikely to fail. But most folks don't know the difference between an antenna, and a full GPS "puck" which is the whole electronics package installed with a patch antenna all in what looks like a hockey puck or mouse. That's got more active electronics and is more likely to fail. And, a "watch" battery to preserve memory while the system is off. That battery can go bad after 5-10 years.

But whenever there is a coaxial cable, with end fittings crimped on, usually chafing where it penetrates the decks? Checking out the cable is a good place to start.

You'd need to check on what your system uses, a "GPS puck" or just an antenna, and if there are suggestions to check that out.

[txh2oskier]

My "antennae" resembles the mushroom that Moody46CC mentioned. Not that it makes any difference, but a bit of a typo, my chartplotter is C80.

Thanks for all the responses and I'll see what I can figure out this weekend.

Brian

[Dockhead]

Originally Posted by Moody46CC

I had a Raymarine mushroom-like GPS antenna fail. As I recall, the chartplotter could not get a fix on a signal. A technician said the unit (sealed) had a battery, so he replaced it with the up-to-date model. That unit worked fine and was working when I sold the boat. Sadly, I do not recall the model number of the failed antenna.

These things are not actually antennae -- they're receivers, with antennae.

The Raymarine ones are notorious for battery failure, but this usually just means that they just fail to store the satellite catalog or whatever it is they need to start up quickly, with the result that if you wait patiently for them to download the information they need (10 - 15 minutes), they will come back on line. Battery replacement is fairly simple; plenty of information in the archives about it. I lived with this problem for a couple of years with my old system -- it was not so much trouble that I felt compelled to replace the battery. Just start up the electronics some time ahead of casting off.

But they're so cheap now that you might almost as well buy a new one. There has been a lot of improvement in the technology over the last 10 years. The new ones are much more sensitive (they work below decks), startup much faster, and some of them receive the Russian GLONASS system, which in my book is an absolutely enormous advantage, in case of some outage of the GPS system. I have as my main position data source a Simrad GS25, which only cost $200, and which receives every possible system, and also differential corrections in the US (WAAS) and Europe (EGNOS). I use it with an N2K network, but I believe that it outputs 0183 as well.

[rwidman]

Thinking about my antenna problem (a Garmin GPS 17), I can't find any information on the web about an internal memory battery. Does anyone know if there is a battery in the GPS17?

As I mentioned, I have a spare but if there's an internal battery, the battery in the spare would likely be at the end of it's life as well.

The replacement, a GPS 19 is close to $200 so I would rather replace a battery if that's the problem.

I'll go to the boat and investigate as soon as I can but if anyone knows, I would appreciate the information.

[a64pilot]

The information that the GPS stores that Dockhead refers to is called the Almanac, it tells the GPS where the Satellites should be based on a time and a date.
One way to be pretty sure the battery is dead is if when you first turn the GPS on, if the date is off by years, then it's lost the Almanac and can not do a "hot start", it has to do a "cold start" and download the Almanac etc before it can find itself.
It will work, and doing consecutive cold starts will not hurt the system, just it takes quite a while before you get a fix is all.

I believe all GPS antennas are active, meaning they require power, but I also believe most of the small antennas like the newer Garmin ones are just antennas, but just from looking, it appears that the Garmin GPS 17 that the actual GPS is the antenna itself. I have no idea how to change a battery in it or if it has one either though.

[rwidman]

Originally Posted by a64pilot

The information that the GPS stores that Dockhead refers to is called the Almanac, it tells the GPS where the Satellites should be based on a time and a date.
One way to be pretty sure the battery is dead is if when you first turn the GPS on, if the date is off by years, then it's lost the Almanac and can not do a "hot start", it has to do a "cold start" and download the Almanac etc before it can find itself.
It will work, and doing consecutive cold starts will not hurt the system, just it takes quite a while before you get a fix is all.

I believe all GPS antennas are active, meaning they require power, but I also believe most of the small antennas like the newer Garmin ones are just antennas, but just from looking, it appears that the Garmin GPS 17 that the actual GPS is the antenna itself. I have no idea how to change a battery in it or if it has one either though.

Yes, for nearly $200, the "antenna" had better be the GPS. I did have the presence of mind to put the extra one (one came with each MFD) on the boat for a spare but that means I can't look at it without going to the boat.

Swapping them out would seem simple but running the cable from the flybridge to the lower helm is no picnic. The raceway is packed.

[bratzcpa]

This has been an interesting (enlightening??) thread.

A year ago, my Lowrance unit with an extenernal GPS "antenna" (this is the flat puck style, I think it's a LGC-1000 or 2000??). After monkeying around with it, I concluded that it "failed" and rather than replace the antenna (at about $200), I upgraded the unit and went with an internal GPS. very happy.

BUT, in reading this thread, perhaps just a "battery failed in the external antenna thing"??? Can anyone shed any light on that? How can I check that? Does the LGC actually have an little built in battery?

thx,

~markb

[lsearite]

How timely this has come up. Last week a friend was telling/asking me about his antenna. He said a mechanic told him his radar had over time, like 5 years, fired the antenna. He runs his radar every time he moves. Kinda made me shake my head. Any knowledge?

[highseas]

My Raymarine C80 "Raystar" antenna failed.I was in some heavy weather with a lot of water over the boat,a couple of days later no fix.Didn't know about internal battery but doubt that was cause being only 1.5 years old,may have been cable failure.New one was over $300.,worked fine ever since.

[nigel1]

Originally Posted by bratzcpa

This has been an interesting (enlightening??) thread.

A year ago, my Lowrance unit with an extenernal GPS "antenna" (this is the flat puck style, I think it's a LGC-1000 or 2000??). After monkeying around with it, I concluded that it "failed" and rather than replace the antenna (at about $200), I upgraded the unit and went with an internal GPS. very happy.

BUT, in reading this thread, perhaps just a "battery failed in the external antenna thing"??? Can anyone shed any light on that? How can I check that? Does the LGC actually have an little built in battery?

thx,

~markb

On my last anchor handling tug we had three Furuno GPA019 GPS antenna's mounted on top of the mast. All three failed within a 4 week period, being about 2 years old at the time.

Contacted Furuno, they could not explain the failures, so go figure, could be a bad batch I guess, but at $300 each, would have expected better.