Can anyone identify this GPS antenna?

[Grumpydev]

I suspect I am going to need to replace my GPS antenna as it looks like its falling foul of a GPS date rollover issue, but I wondered if anyone could help identify it so I can gauge what type of wiring/connector it might have on it without me removing it from the arch? Its connected to my axiom pro via an old school NMEA gateway adapter thing, so there's no identifier I can see beyond that on the MFD.

 

[jfm]

It's a mushroom not an antenna and from those curves in the moulding it's a raymarine. Raystar 125 +130 (maybe also 150) models use that moulding.

You don't need to replace with same because they are generic, within each output type. However that one probably outputs NMEA2000 "packaged" as Raymarine's annoying SeaTalk NG, so to keep things simple you are probably better trying to replace it with an identical one if you want an easy straight swap. If you get another one you can connect it to the backbone down in the helm area to try it out, before you set to work up the mast.

 

[Wandering Star]

Probably a Raystar 125 - the small LED is the giveaway identifier.

 

[oldgit]

First sign of the GPS receiver failing is very slow to detect any satellites and then only one or two at most.
Problem solved with choice between paying for a genuine Raymarine replacement or buying one of the myriad of cheap clones on Ebay for around £50-60.
Have replaced Raymarine mushrooms on older chartplotters with budget copies in the past, all have worked perfectly first time and lasted at least till the boat was sold.
Assume Axiom is no different. ?
The ebay receivers are usually complete with a diagram of how to match up your old Raymarine wiring colours to the colours on the replacement.
In my case suffient slack immediately under the mushroom to pull its connecting wiring up enough to solder to new mushroom wiring .
Saved dismantling most of the boat to replace entire loom.

 

[vas]

+1 on Ray 125.
no one mentions replacing the CR2032 battery in it (iirc)
have one, have replaced the battery still works in a friends boat now.
Led on top is not particularly bright but will give you indication if what may be wrong with it, flashes orange or green (check the manual don't remember ofhand) one is trying to connect, the other is that it has established connection.

the way it's fitted means you have to undo the back cover of your arch to get access to the 3(?) screws holding it down. And hope it's watertight up there else it's gone!

cheers

V.

 

[st599]

First sign of the GPS receiver failing is very slow to detect any satellites and then only one or two at most.
Problem solved with choice between paying for a genuine Raymarine replacement or buying one of the myriad of cheap clones on Ebay for around £50-60.
Have replaced Raymarine mushrooms on older chartplotters with budget copies in the past, all have worked perfectly first time and lasted at least till the boat was sold.
Assume Axiom is no different. ?
The ebay receivers are usually complete with a diagram of how to match up your old Raymarine wiring colours to the colours on the replacement.
In my case suffient slack immediately under the mushroom to pull its connecting wiring up enough to solder to new mushroom wiring .
Saved dismantling most of the boat to replace entire loom.

The date rollover doesn't show as a loss of satellites. The week number is a 10 bit number, so every 1024 weeks it goes back to 0 and, if the firmware isn't expecting it, your date jumps back 1024 weeks and it tries to find late '90s ephemera to calculate position.

 

[Grumpydev]

Thanks for the replies, its getting a fix just fine, just the date is significantly out (1024 weeks out is about right I think), I did suspect it was an RS125, but the lack of RayMarine branding (even faded) made me doubt it - the 125 had its "rollover day" in 2022, so that fits in with the previous owner not noticing/realising (it pretty much wasn't used in 2023)

For now I've switched the axiom to just use the internal GPS for time signal, and use the external one for positioning, and it seems happy enough, but I'll stick replacing it with an RS150 on my list of jobs, although it will mean running a new cable I think as I think the RS125 is an older style connector/cable (its hooked up via a ST->STNG bridge thing at the moment) - cable pulling up to the radar arch doesn't sound fun

 

[PaulRainbow]

Thanks for the replies, its getting a fix just fine, just the date is significantly out (1024 weeks out is about right I think), I did suspect it was an RS125, but the lack of RayMarine branding (even faded) made me doubt it - the 125 had its "rollover day" in 2022, so that fits in with the previous owner not noticing/realising (it pretty much wasn't used in 2023)

For now I've switched the axiom to just use the internal GPS for time signal, and use the external one for positioning, and it seems happy enough, but I'll stick replacing it with an RS150 on my list of jobs, although it will mean running a new cable I think as I think the RS125 is an older style connector/cable (its hooked up via a ST->STNG bridge thing at the moment) - cable pulling up to the radar arch doesn't sound fun

@Grumpydev Why not just use the internal Axiom GPS ?

 

[Grumpydev]

I don't think its as accurate? And I don't think the signal would be as good at the helm as it would be on top of the arch.

 

[PaulRainbow]

I don't think its as accurate? And I don't think the signal would be as good at the helm as it would be on top of the arch.

Can't see why it wouldn't be as accurate. I've fitted many, many plotters with built in GPS and never had a problem with reception below decks. Why not give it a try ?

 

[Grumpydev]

Can't see why it wouldn't be as accurate. I've fitted many, many plotters with built in GPS and never had a problem with reception below decks. Why not give it a try ?

When I (briefly) checked it the internal one was reporting an accuracy of +/- 1.5metres, which didn't seem that great, but I'll give it a go next time I'm at the boat and compare it to the external signal/lock

 

[PaulRainbow]

When I (briefly) checked it the internal one was reporting an accuracy of +/- 1.5metres, which didn't seem that great, but I'll give it a go next time I'm at the boat and compare it to the external signal/lock

I'll be very surprised if the Raystar 125 is much better then 3 meters. Be interested to read your findings.

 

[Momac]

Within 1.5 metres accuracy seems quite sufficient.
By the way you can search for images on Google. I took a clip of the antenna from your photo and found the make and model quickly.