Chartplotter aerials ?

[biscuit]

I recently replaced an old dead Garmin GPS 152 NMEA 0183 (with external aerial) at my nav. station with a Garmin echoMAP CHIRP plotter using the NMEA 0183 output to my GMDSS VHF. All worked well but the subsequent installation of a new flexible chart light just above it has interfered with the signal, making it unacceptably slow to find a position. I don't want to move the new plotter, having cut a hole for it on the instrument panel.
OK, it's not a big deal: I can work around this by simply pulling the chart light out of the way, (this works ) or fit a different type. I could also connect the main binnacle plotter to the VHF to show position, but may have to wrestle with the cable runs. Garmin suggest using a 19x aerial in this situation (at a cost of 170 pounds). I don't understand why I can't use the old external aerial (which seems to use a simple co-ax. wire) to boost the signal.
Could someone please explain?

 

[pvb]

I don't understand why I can't use the old external aerial (which seems to use a simple co-ax. wire) to boost the signal.
Could someone please explain?

Your old antenna is just a passive antenna. Your new plotter requires an active antenna (which has the GPS receiver built in).

 

[biscuit]

So it needs a second GPS receiver in the aerial as well as the one in the instrument?

 

[ithet]

From echoMAP™ CHIRP 75dv spec: "Antenna Internal_or_external_over_NMEA_2000"

However, they list an antenna option NMEA0183 GPSHV19x HVS as an accessory, so presumably it can take position info over NMEA0183.

 

[biscuit]

Yes, can use either 0183 or 2000

 

[pvb]

So it needs a second GPS receiver in the aerial as well as the one in the instrument?

Correct, if you want to use an external antenna. You don't have to buy a Garmin 19x, any active NMEA antenna would do. The Evermore SA-320 is often recommended, at about half the price of the 19x.

 

[biscuit]

That's very helpful. I have just looked up a previous thread and they seem to work well. Thank you.

 

[pvb]

That's very helpful. I have just looked up a previous thread and they seem to work well. Thank you.

Just a cautionary note. Your plotter only has one NMEA0183 port. You can use this to input the GPS position, but if you were thinking of adding AIS data, you might need to use NMEA2000 for that (or use NMEA2000 for the GPS position, leaving the 0183 port free for AIS in the future).

 

[biscuit]

OK, thanks. I don't intend to use it for AIS, as I use the plotter at the binnacle for that, but worth bearing in mind.

 

[scottie]

What is the bulb in the new light
Is it led?

 

[prv]

So it needs a second GPS receiver in the aerial as well as the one in the instrument?

Instead of, yes.

Pete

 

[biscuit]

Bulb is simple incandescent type. Signal block occurs with the light off. It seems that it is the flexible coiled steel arm that is blocking the signal, until moved out of the way.

 

[pvb]

OK, thanks. I don't intend to use it for AIS, as I use the plotter at the binnacle for that, but worth bearing in mind.

Is the binnacle plotter networked to the chart table plotter?

 

[Baddox]

I wired a GlobalSat BR-355 BR-355 Serial GPS Receiver to my VHF to provide the lat/lon via NMEA wires and it worked. It was cheap and simple, but a while ago so I'll not recount the details. There was plenty of info about it online.