# help SFW>!!!!!!!!!!!!!!!!!!!!!!!!!!!



## shametamer (Jul 22, 2001)

help SFW>!!!!!!!!!!!!!!!!!!!!!!!!!!!.....internal or external antenna for gps..preferences? pros , cons?


----------



## omegasniper86 (Feb 15, 2007)

I have the internal antenna on my 522 lowrance gps , the pros would be the installation. Dont know of any cons unless you have a hard top boat, i have a full windshield and the top is wide open. I used it with the binimi top on and still no problem. My father in-law has external anntenna garmin gps(older modle) and he hook my unit up on my boat and said it was a breeze installing it compared to his external unit.


----------



## sfw1960 (Apr 7, 2002)

*What are ya lookin' @ Shamey???*
:evilsmile
I have BOTH of my gimbal mounts ('Bird 797c2SI & Low. LMS332c) W/externals - as I am quite sure (from all the online stuff I've read) they get a clearer view of the SATs. and therefor do NOT lose a fix on the 'stars' anywhere near as often as the internals.
Add the fact that you CAN mount your GPS puck right over the XDCR and you can't get anymore accurate when you drop a waypoint.
:fish2:
Cripes even my old dinosaur Eagle AccuNav Sport "hand held" (it's H U G E ) has an external antenna!!!
I'm surprised ya didn't PM me.... I suspect Steve (hitechman)will be appearing here shortly also.



RAS


----------



## Shoeman (Aug 26, 2000)

Here's my take

I've had both. My latest is a 339 w/ the internal. Usually not an issue, unless someone (big) is blocking the SW view. The same is true with my XM. "Hey, get your physique away from my reception"...LOL

I think the external mounted flat on the bow is the ticket


----------



## sfw1960 (Apr 7, 2002)

Some guys mount them too close + block the 'view'


Shoeman said:


> Here's my take
> 
> I've had both. My latest is a 339 w/ the internal. Usually not an issue, unless someone (big) is blocking the SW view. The same is true with my XM. *"Hey, get your physique away from my reception"...LOL*
> 
> I think the external mounted flat on the bow is the ticket


:lol: :lol: :lol:
Good'n RalF!!
I have BOTH mine mounted on my splash guards on std. 1x14 marine antenna mounts & since theres 2 batts in that corner (16' tiller) NOBODY "shades" them out!
:evilsmile

*R*


----------



## hitechman (Feb 25, 2002)

I've been in Canada fishing (and using my GPS:lol: ) for the past 9 days. Did a little geocaching on the way up and back as well.

I'll try to keep this as nontechnical as possible. External antennas *usually* offer a much higher gain (kind of like an amplification of signal reception). Even if they offer no gain they usually offer an obstructed sky view--by this I mean no hands or bodies in the way of signal reception (not referring to trees and other overhead obstructions). External antennas are often placed on metal surfaces, thus increasing the ground plane (read this as stronger and more uniform signal reception). Some external antennas also offer power amplification of signal as well. Mounting an external antenna on a substance other than a metal reduces their efficiency (reduction in gain).
External antennas are not very portable, but a buddy of mine has one mounted on the top of a metal safety helmet and his signal is usually double that of my internal antenna (but he looks really wierd walking around like that).

Internal antennas are subject to position (how the unit is being held). Holding you hand or fingers near or over the antenna will affect reception (usually in a negative way), plus your body may be blocking some signal. Some internal antennas are meant to be held horizontally and others vertically. Sometimes this can increase signal strength--ever put your hand next to an antenna on a portable FM radio and hear the station come in better? Most internal antennas have a very small or nonexistant ground planes-not extremely important since the RF field from a satellite above your position is very spherical as opposed to a ground signal which is rather elliptical (better signal in one direction as opposed to another), and its shape is greatly influenced by surface geological features.

The external antenna always (usually) stays in the same horizontal-vertical position because it is permanently affixed. An internal antenna on a hand held GPSr is constantly changing its orientation just by the nature of carring the unit, and thus there is more variation in signal strength.

Hope this helps.

Steve


----------



## sfw1960 (Apr 7, 2002)

So it was a 787c2 (right?) WITH external????
:evilsmile :evilsmile:16suspect:evilsmile:evilsmile


----------

