Internal or external reciever

[powert]

Hi,

i was sifting through various sounder/gps combos and was curious to know what the advantages/disadvantages were of internal and external satellite receivers.

any advice would be appreciated

[TheRealAndy]

If you in an open boat (centre console) then you can use an internal antenna. If your in a half cab with a roof then you would use the external antenna.

The great thing about an external antenna is you place it where you get the best reception, and just remeber it does not take a lot of physical obstruction to kill the signal. I do a lot of hiking and I cant use a GPS in rain forest because of the tree canopy, its all map and compass for me.

[bigbrian47]

internal aerial is fine on a dash under a bimini etc
i've had one for a couple of years now with no problems
same in my 4b in the bush the only problem is overhead trees
have had a dash mounted lowrance in the 4b for 10 yrs no problems
except thick scrub
as TRA said a compass is an essential backup anyway both bush&water
cheers brian

[SatNav]

1. The decision depends on how much of a compromise you are prepared to accept

2. Depends on the actual mounting location relative to the user and other physical surroundings

3. External should always be the preferred option if available

4. There is no way to determine if an internal mount location will be ok as it is not the present signal that is important but the future signal.

5. The strength/quality of the signal today may not be the same when circumstances change

[dnej]

And as it was explained to me,why not get the external,because it can then be an either or situation,not being limited to where the antennae,can be mounted.
David

[BaitThrower]

Might also depend on brand of the GPS. I can get an accurate signal inside my house on an overcast day on the handheld Garmin GPSMAP 76CSx which has internal antenna. It takes alittle longer to acquire indoors thatn outdoors of course but it does get a signal and quite an accurate fix. Using it in rainforest with overhead canopy is no problem either. So might be worth asking around about brand and models too. Some are better than others!

[SatNav]

1. Getting a signal inside a house is dependant on many things including what the house is made off and other physical/environmental elements.

2. Accurate signal inside house? Based on what reference?

3. Overcast day? Will not affect GPS signals at all

4. Antenna's come in all shapes, sizes and class but even very sophisticated antenna's worth a few thousand dollars will not give an accurate position indoors

[Hamish73]

GPS signal inside a house? Are we talking about a greenhouse here

But seriously, I have had a range of garmin handhelds, and as far as I know they all have the same 12 channel reciever, and none of them have ever worked inside our old weatherboard house. I do a lot of enduro riding through trees etc and generally GPS distance is about 90% of real distance, so it does a pretty good job of maintaining signal

[bluefin59]

I have a navman g.p.s with built in anntena and i can get a signal in a garage brick and tile with the garage door closed so i dont think a built in anntena is such a big problem ...matt

[SatNav]

1. Brick walls, tiled roof? Might be ok, Why don't you try a tin shed, tin roof and even leave the door open if you wish.

2. Boats don't always live in sheds do they?

[bluefin59]

No they dont mate ll i am saying is if i get a signal in there it wont be a problem on the dash of most boats ,i have taken mine out in a 6m hard top trailcraft and it worked fine....matt

[SatNav]

1. The point I am trying to get accross is that just because it works today does not mean it will work tomorrow as GPS service is not totally predictable and should not be expected either.

2. Because you get a signal only indicates that at particular point in time you are getting a signal, it does not indicate future possibilities.

[seatime]

1. The point I am trying to get accross is that just because it works today does not mean it will work tomorrow as GPS service is not totally predictable and should not be expected either.

2. Because you get a signal only indicates that at particular point in time you are getting a signal, it does not indicate future possibilities.

Can you can add to that, inside a structure on land the aerial (internal or external) isn't moving about as the unit/aerial will often do when on the water.

[Xtreme]

Powert,

I'm with SatNav, internal aerials are an easy option but thats where the benefits stop. In my practical experience with Lowrance units, the internal aerial units take longer to lock on satellites and hold fewer locks. They'll still work mind you but they are not an equivalent IMHO.

[joeT]

Units with an inbuilt antenna usually can't be flush mounted.