GPS Antenna ?

[Legend]

HI. Purchased a new multi-function Garmin GPS unit and it says it has an internal antenna. Has the option for an external antenna. Anyone with a fairly new GPS using just the internal antenna and is so any issues with satellite reception? The unit is to be installed in a Sailfish, under the hardtop and surface mounted in the cockpit. Thanks for any feedback.

 

[Coastboater]

I’ve installed a few, all with internal antenna and never had a problem picking up satellites. A couple were hardtops.
You should be fine and if not add the external antenna later.

 

[Halfhitch]

Same as Coastboater here. Just connect your Garmin to a NMEA 2000 system and all your other instruments will be able to make use of it. Like your VHS, autopilot, or any NMEA 2000 capable gizmo.

 

[Ekea]

mine is mounted just above my steering wheel (so lower than yours), i have no external antenna and it does fine

 

[SkunkBoat]

The internal GPS should be fine. It will share with the network.

To clarify though, external GPS "antenna" is a misnomer. Nowadays, the NMEA2k units are actually a complete gps receiver and antenna, powered by the n2k.

Garmins latest version is GPS24xd that also has a built in heading sensor. Your chartplotter does not have a heading sensor.
A heading sensor gives an accurate display of where the bow of the boat is pointed, even when you are not moving. Without a heading sensor, the gps heading is calculated based on movement (it assumes you are moving forward). Under 3mph you may not get a good gps heading. When you are drifting, the display will show the bow pointed in the direction you are drifting, not the direction the bow is actually pointed.

Radar and Autopilot will require a heading sensor.



The Garmin mfd can be set to use the built-in or choose from network gps units if you have more than one.

IDK what you had before. If you had any brand of n2k gps unit, it will work if its on the network.

 

[Sardinia306Canyon]

I had many GPS on my boats and all are installed on the dash on the console and GPS reception worked fine.
However, depending on position, materials, cable mess, hard top structure reception of GPS signals can be reduced.
I have now a 800$ Garmin MSC-10 Satellite Antenna acting as Heading Sensor and Multi-band GPS Receiver and it's a different world. Buch better AP accuracy, very good GPS SIgnal strength and Heave Compensation for my GT51M-TM.
Normal NMEA2000 GPS antennas cost around 2-300$ what i find a acceptable cost for more accurate position data, if internal GPS antenna has limited reception.
Chris

 

[wahoo33417]

My Garmin works really well flush-mounted at the dash under the Sailfish hardtop. Also seems to give great position data to the autopilot.

Like Coastboater said, try it. You can always add the GPS/heading sensor later.