GPS/Internal antena

[Cool It]

hey guys<br /><br />is a gps w/ internal antena just as good as one with external??<br /><br />Thanks<br />Cool It

 

[Dunaruna]

Re: GPS/Internal antena

No, an external will lock on faster and more sats. Don't have to worry about windscreens & frames and bimini's/hardtops etc.<br /><br />My handheld takes ages to find 3 or 4 sats and then it drops out if your not holding you're tongue right, my fixed (external arial) finds 6 or 7 within 30 seconds.<br /><br />Aldo

 

[amirm]

Re: GPS/Internal antena

I find the newer generation antennas (for the PC at least) to be exceptionally sensitive. I have no problems with them anywhere inside (last generation ones were terrible). Of course, as Aldo says, external antenna always works better.

 

[Boatist]

Re: GPS/Internal antena

No the external is better.<br /><br />Still internal work very well at finding your position. You did not give your location but in the US area only 2 WAAS satellites. These satellites are in Geostationary orbits so are over the equator and 23000 miles high. AOR-W (Alantic Ocean Region West) is at 54 degrees West and POR (Pacific Ocean Region) is at 178 degrees East. So these WAAS Satellites will be low on the horzion and east or west of the us. This means signal is weak and can easily be blocked by structure between your antenna and the Satellite. The internal antenna is in the unit so you will mount it where you can see it but it may not be able to see a satellite low on the horzion.<br /><br />Units with external antenna the antenna can be mounted where structure on the boat will not block the view of the WAAS satellite.<br /><br />If you can recieve the WAAS satelite then accuracy is as good as 10 feet or 3 meters. If you can not see WAAS staelites then Accuracy more like 30 feet or 10 metters.<br /><br />The 24 Normal GPS satellites is 12,600 miles high and could be straight over head. The way the system is set up will always be able to see 4 and may see 7 or 8 so Internal antenna can normally get thise birds and give you a position.

 

[JB]

Re: GPS/Internal antena

An internal that has an unobstructed view of the sky does just as well as an external, but if there is any obstruction of the sky view for the internal the external works better when placed where there are no obstructions.<br /><br />I haven't had any experience where the internal didn't do the job, even on the dash of my truck.

 

[gss036]

Re: GPS/Internal antena

Boatist is right about the WAAS being difficult to get. I boat in the San Juan and Canadian Islands and very seldom get WAAS. I depend on my Loaran for a couple of the tight 25-50 ft wide passes I go through on occasion. I am using a Garmin 176C w/internal antenna.

 

[Boatist]

Re: GPS/Internal antena

Cool It<br />I said external is better and it is but internal also has some advantages. Also remember both will receive the standard GPS Satellite Only the WAAS satellites low in the sky and hard to receive. The WAAS satellites just improve accuraccy of the other satellites. Still the difference in accuracy is 20 feet. 10 feet at best with WAAS and 30 FEET without WAAS. <br /><br />So if you are useing a unit you switch from the boat to the car the internal would be better. In the car a difference of 20 is going to make no difference. Out on the water a difference of 20 may mean it takes you twice as long to find that little rock pile that always holds fish.

 

[Boatist]

Re: GPS/Internal antena

JB<br />Garmin units I think alway reserve the last two Satellites position for WAAS satellites if you have WAAS enabled. In the USA they will be POR (Pacific Ocean Reagion) Garmin # 47 and AOR-W (Alantic Ocean Region West) Garmin # 35. I know you are in a southern state of Texas but wonder if you actually recieve the WAAS birds while in the car. Looking at the satellite foot prints it does not look like POR Garmin # 47 at Latitude 0 Longitude 178 East has coverage over Texas. AOR-W Garmin #35 at Latitude 0 Longitude 54 West has strong coverage for Texas. When you look at your satellite page do you get signals from #47 POR? Do You get #35 AOR-W? I think your should as you are pretty close.<br /><br />At my Location Latitude 38 Longitude 121 I can recieve both POR and AOR-W with my Garmin GPSMAP 76 internal antenna but in the car rarely get either. Out on the open water can get both if I bring unit out of the cab area to the back of the boat where I have is clear view to the south. I supect people up North in the USA Have a harder time geting either with the internal antenna.

 

[dingbat]

Re: GPS/Internal antena

I'm sitting at 38 lat and 76 long and don't have a problem picking up the WAAS birds. I’m using a fixed mount 182 with the antenna mounted on the hardtop. Twelve birds is the norm and I typically see 3 meter accuracy or better.

 

[Boatist]

Re: GPS/Internal antena

Dingbat<br />From your location you should have no trouble geting AOR-W garmin number 35. Even from California we can receive it. You will not be able to pick up POR garmin number 47.

 

[Cool It]

Re: GPS/Internal antena

Thanks<br /><br />I might just grab a quick hand held for this year . before it goes in again next year I will put the whole system GPS/FF in. I have the Hummingbird on my old boat and it works great. But the $$ are tight, all went on the price of the boat!!!!<br /><br />Thanks<br />Cool IT

 

[Boatist]

Re: GPS/Internal antena

Cool It<br />That is what I did also. I am still useing my old Loran C unit as my main navigation but got a Garmin GPSMAP 76 as a backup and to save as many of my old waypoints as I can.<br />Works very well in the car also or if I go out on a party boat to record where we fished.<br /><br />Should one have a really bad day and end up in the water it should still work. With a waterprof VHF handheld you have a chance.

 

[DangerDan]

Re: GPS/Internal antena

I'm in Michigan @42.06N 86.29W. I pick up wass and 9 to 12 sats without problems. I have a unit that came with both internal external antennas. I installed my external on my arch. I disconnected the external to see if there was any difference in my reception or capture time and didn't notice a darn bit of difference either way. I havent ever experienced any problems with my external diaconnected. I am usually just using the internal antenna.