No fix on plotter.

KREW2

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As per title.
I picked up my new to me boat Monday from Cowes to bring it to Weymouth. As I approached the fuel berth the C80 plotter lost its fix, and the ST4000+ displayed SEATALK FAIL After not picking up any satellites for ten minutes I turned the plotter off, as I wanted to use the autohelm.
I have been told I need to replace the GPS antenna JG technologies sold me one of these Raystar NMEA aerial (jgtech.com)
My problem is the 5 pin connector on the back. It says NMEA in and NMEA out, nothing about a 12v power supply needed for the antenna.
Anybody else changed their antenna on a Raymarine C80.
 

Jamie Dundee

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As per title.
I picked up my new to me boat Monday from Cowes to bring it to Weymouth. As I approached the fuel berth the C80 plotter lost its fix, and the ST4000+ displayed SEATALK FAIL After not picking up any satellites for ten minutes I turned the plotter off, as I wanted to use the autohelm.
I have been told I need to replace the GPS antenna JG technologies sold me one of these Raystar NMEA aerial (jgtech.com)
My problem is the 5 pin connector on the back. It says NMEA in and NMEA out, nothing about a 12v power supply needed for the antenna.
Anybody else changed their antenna on a Raymarine C80.
Why does the antenna require an external power supply? Most work directly from NMEA. The power part of the cable is to power the plotter, not the antenna.
 

KREW2

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The new antenna comes with 4 wires, NMEA in NMEA out, plus a Red+ Black- and a shield. John at JG Tech said the antenna will need a + and - feed to power it
I will go down to the boat shortly and test the pins on the connector with a multimeter and see if I get a 12v reading.
 

Bilgediver

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Sandy

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I looked up the spec for the C80 and wonder if there is an internal GPS ? Personally, I'd only ever use the internal GPS is there was one.

C80 GPS Chartplotter
Connect an optional Raystar GPS Sensor and choose Navionics charts to transform any C-Series display into accurate and detailed GPS charting system.
 

KREW2

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Is it a Seatalk 5 pin connecter and is it the same as the connector on your C series connector box. Seatalk connectors/ cable carry the 12 v supply.

An interesting discussion elsewhere.

Seatalk2 to seatalkng for classic series MFd - Cruisers & Sailing Forums

Yes it is a 5 pin connector, and goes into the nmea socket here. The only other cables connected are radar, seatalk (not seatalk 2), and power, so 4 cables in all. What I would like to know is how does it get its GPS signal?:confused:
1642611079613.png

Having said all that. Yesterday I spent 3 hours fiddling with no success. Today fiddling, and not really knowing what I was doing it started tracking satellites and worked:confused: . In Cowes it worked for about 10 minutes then stopped once I started moving, so I shall have to wait and see.
 

Slipstream 34

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If it's a Raystar 120/125 the internal battery may need replacing. With no back up battery the satellite almanac is no retained. With no stored almanac if GPS tracking information is lost momentarily, leaning over the GPS unit can do it, then it has to reacquire each satellite as in a cold start which can take several minutes. The batteries are easy to replace - plenty of advice on the forum.
 

jwilson

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C80s definitely don't have an internal GPS. The old external GPS mushroom will probably be a long obsolete Raystar 120 or 125, which can often be magically rejuvenated by fitting a new tiny internal lithium battery. Most Chinese replacement GPSs need a separate 12v power supply, and won't use the same old Raymarine cable.
 

KREW2

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If it's a Raystar 120/125 the internal battery may need replacing. With no back up battery the satellite almanac is no retained. With no stored almanac if GPS tracking information is lost momentarily, leaning over the GPS unit can do it, then it has to reacquire each satellite as in a cold start which can take several minutes. The batteries are easy to replace - plenty of advice on the forum.
That's the trouble I have all the manuals but, I have no idea what sort of antenna it is. I will get everything out again tomorrow and try to find out whats what
 

Norman_E

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From the page the OP linked to:
`Comes complete with wiring details for using this with the legacy Raymarine C70 C80 C90W C120 C120W E80 E120 E120W plotters.`
 

Bilgediver

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From the page the OP linked to:
`Comes complete with wiring details for using this with the legacy Raymarine C70 C80 C90W C120 C120W E80 E120 E120W plotters.`


This is what I understand from his various posts. This means his new GPS antenna came fitted with a 5 pin Seatalk plug. this means that if it s plugged into his Seatalk box then the antenna should get 12 volts from the Seatalk box and the nemea signal will connect to the Seatalk using pins in the plug. For thgis to work hes plotter should also be connected to the Seatalk system.
 

KREW2

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The antenna seems to be inset into the wheelhouse roof, but the top certainly looks like the 125 model.
New antenna came with no plug the cable has two nmea wires and a positive and negative a shield. I was told to use my old nmea cable and connect it to the antenna, but there is no 12v power supply from the nmea at the back of the plotter.
 

jaminb

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When we picked up Inge from Portland to bring her back to Southampton, we had a Seatalk Error 2 come up on the autopilot control. It was very intermittent. Greenham Regis diagnosed the problem as an unstable power supply. The previous owner had fitted a TV, sound bar and Invertor and had powered them via the same circuit as the cockpit instruments. Oh how we laughed!
 

KREW2

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An update, well it was the antenna.
I installed the new one and the plotter picked up several satellites very quickly. So far so good, but within seconds the STLK FAIL came up on the ST4000+
I shut both down powered up again and the same thing happened.
In the end I got it all working by trial and error. If I power up the plotter first, let it get a fix then power up the ST4000+auto helm works, displaying STANDBY, and GPS page shows plenty of satellites with a strong signal
But, if I have the ST4000+auto helm display powered up, and then turn on the plotter on it struggles to pick up satellites.
Anyone have any ideas on this.
 
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