Thread: Gps

External antenna units are mostly for boats with the head unit under cover or mounted in the dash where an internal antenna wouldn't be able to "see the sky".

I have a 5200c and a 5300c --not a bit of difference in their working,s

Some of the differences you will hear about will have to do with when the internal GPS unit was made which has to do with the location of the actual internal GPS Receiver. The current internal GPS models that Humminbird makes have the GPS Receiver located just behind the front housing and so are made for indash mounting. Older (pre-2009) models did not and would only sometimes work when mounted in the dash. As long as you do not have a metal roof, metallic bimini top or something like that the newer internal models when mounted indash should work just as well as an external GPS model would.

Another wrinkle with the internal versus external GPS Receivers is that (again depending on the year model of the internal GPS unit) the external GPS Receivers would have faster start up times and would work in a higher noise environment better than the internal GPS models would. Some even use a different model GPS Receiver in the internal versus the external and so there could be noticeable performance differences.

Of course with the internal GPS units when the GPS goes out you have to send the whole unit back to be worked on. With the external GPS models you may be able to just send the GPS Receiver back and would still have sonar capabilities. Than there is the not having to mount the GPS Receiver deal for the internal models.

And lastly there is the ability to mount the external GPS Receiver closer to the transducer for that same unit. This will help give better accuracy when marking waypoints that are based on the sonar information.


Greg Walters at Humminbird