gps antenna

[JJO]

which is better a internal or external gps antenna, i have not hard top just a bimini top.

 

[estebanj]

As long as the antenna has clear sight of the sky, no difference for practical purposes. How covered will the internal antenna unit be under the bimini?

Esteban

 

[Tallahassee240Sundeck]

I have a Garmin 440S that is mounted on my dash under the bimini... internal antenna and it works great...

 

[Dave S]

Generally speaking the antenna can shoot thru glass, canvas, and even fiberglass. If the unit you want comes with a built in, that may be the easiest way too go. But f you want to buy a seperate antenna, it could be mounted on top of the dash or even under it. I have two chartplotters for my boat. I actually mounted the antenna under the dashboard for one of them so it would not be visible and it works fine. In fact it works just as well as the other one which has the antenna mounted on top of my arch.

 

[mawyatt]

GPS signals come from low earth orbiting satellites and the signal power is very low at the earth's surface. Multiple satellites are required to get a position "fix" as they pass over, many are acquired at low angles where the signal power is even lower. Any obstruction can degrade the signal and effect acquisition time or cause loss of "lock".

Various materials will degrade the already weak GPS signal, some more than others, so it's best as mentioned to try and get a clear sky shot if possible.

I have a Garmin 198C which requires an external antenna that I installed on the arch of our 260. Haven't had any problems and it works very well.

Mike

 

[2000SEARAY280SS]

I have a Lowrance unit that has an internal antenna mounted on my dash of an older boat and it works well unless I turn on my depth finder then there are interference problems. I constantly wish I had bought the same unit with the external antenna.

 

[Fishnut]

The manual says that you need to mount the external antenna at least 3 feet from the unit and radio. That is a challenge on a new install I am doing. Has anyone had any luck with putting the antenna closer to the unit or putting it on the outside of the boat next to their VHF antenna?

 

[CSR_Admin]

You can actually put the antenna right next to the unit with no ill effects.

 

[Morpheus]

I installed my Garmin GPS attenna right next to the Sirius Antenna I called Garmin support and they verified before I did it that it would not be a problem and it hasn't been works great. Don't seem to have a picture of it but on my 240SD it's right in front of the helm window.

 

[Taradise]

I asked this same ? at the ATL boat show at the lowrance booth...they recommended external...it the antenna goes 'bad' you dont have to send the whole unit in either...I bought the 525 with external after talking to them.

 

[Presentation]

I asked this same ? at the ATL boat show at the lowrance booth...they recommended external...it the antenna goes 'bad' you dont have to send the whole unit in either...I bought the 525 with external after talking to them.

Just my opinion, if it’s a simple chartplotter and you don’t have a hard top, the internal is a easier installation.

If you are adding a multi-function unit there is validity to having separate components for radar, GPS & depth finder plus equipment monitoring.