Raymarine c70. GPS datum

[Olivia123]

Good morning. I have a raymarine c70 with a seatalk 112 gps. I am having difficulty with the GPs datum. I want it to set at wgs1984 but it keeps changing to one of the hundred others which means the boat on the chart is all over the place. I have the manual and have reset the datum but it doesn't seem to accept WV's 84 and will flit to others. Any ideas please

 

[RichardS]

Which chart are you using in the C70?

Is it the C70 Classic from 10 years ago or something newer?

Richard

 

[Olivia123]

It's a uk navionics chart. It was fine when I had the nmea gps but with the seatalk one it does what it does now. I wondered if that was the problem or just coincidence.

 

[RichardS]

I think the vast majority of C70s are used with Seatalk GPS receivers so that's not unusual in itself but it sounds like your new receiver is telling the plotter to change the datum. If it always changed to one datum I would guess that it is some kind of setting or config issue somewhere but if it selects a different datum at random then I think it must be a fault.

Is the GPS connected correctly to the plotter and are all the connections clean? If it's a second hand GPS is the battery good?

What happens if you disconnect it entirely from the plotter, assuming that you can you get into the datum config screen without the GPS?

Richard

 

[Olivia123]

I don't think there is a problem with the wiring. It looks all good. You are right though it is an old Gps. I never thought of the battery. I think I'll go there next. Thanks for the info

 

[prv]

I don't know whether the GPS transmits datum information along with the position - Thomas Knauf's Seatalk site doesn't list it but that's not claimed to be complete. If it does, which seems plausible, then a flat battery scrambling the config was my suspicion too.

Pete

 

[pvb]

Good morning. I have a raymarine c70 with a seatalk 112 gps. I am having difficulty with the GPs datum. I want it to set at wgs1984 but it keeps changing to one of the hundred others which means the boat on the chart is all over the place. I have the manual and have reset the datum but it doesn't seem to accept WV's 84 and will flit to others. Any ideas please

The Raystar 112's default geodetic datum is WGS-84, so you shouldn't need to change it. If the internal battery has failed, the unit should still operate normally, but it will take some time to find a fix when switched on.

 

[Olivia123]

The Raystar 112's default geodetic datum is WGS-84, so you shouldn't need to change it. If the internal battery has failed, the unit should still operate normally, but it will take some time to find a fix when switched on.

it finds a fix really quickly. But flits from one datum to another. ill try the nmea one back on and see if that makes a difference