External antenna for hiking GPSr

[DougPaul]

I don't agree with that. All the information I've read about these antennas is that they have amplified and have more gain and will pick up birds lower on the horizon than OEM built in antennas. Also I know you have to leave the gps on for quite awhile to get a good data pattern so to say.
Did you try turning it around in a carousel type movement? In a perfect world you'd be stationary and have a clear view of the sky. But when things start changing I believe you would see different results.
Under trees wit leaves,especially wet ones,etc. a antenna with more gain would have an advantage.
Also different GPS's have different antennas. So using the just a 60CS would not mean much.
I find the stock antennas too sensitive to movement and the Gilssons more forgiving.

Sorry, you are WRONG on multiple counts!
(Just for the record, many people have misconceptions about GPSes...)

By way of background, I am a PhD Electrical Engineer with many years of experience in radio. I know what I am talking about. If you have a professional level background, I'm willing to discuss the issues with you offline.

The issue is signal-to-noise ratio. If you already have a decent antenna and a low-noise front-end (most GPSes do), adding another similar antenna and an amplifier will not help. I have answered this question before: see for more detail:
http://www.vftt.org/forums/showpost.php?p=74707&postcount=22

The issue of quadrifilar helix vs patch antennas is also a red-herring. The differences are small, if any. (Consumer external antennas typically use patch antennas.)

Some threads that will fill you in with some info on GPSes:
GPS?
http://www.vftt.org/forums/showthread.php?t=6720
Owl's Head Bushwack
http://www.vftt.org/forums/showthread.php?t=7172
Which GPS is best?
http://www.vftt.org/forums/showthread.php?t=11144

Also http://www.gpsinformation.net has a lot of good info.

Doug

 

[CaptCaper]

Sorry, you are WRONG on multiple counts!
(Just for the record, many people have misconceptions about GPSes...)

By way of background, I am a PhD Electrical Engineer with many years of experience in radio. I know what I am talking about. If you have a professional level background, I'm willing to discuss the issues with you offline.

The issue is signal-to-noise ratio. If you already have a decent antenna and a low-noise front-end (most Gypsies do), adding another similar antenna and an amplifier will not help. I have answered this question before: see for more detail:
http://www.vftt.org/forums/showpost.php?p=74707&postcount=22

The issue of quadrifilar helix vs patch antennas is also a red-herring. The differences are small, if any. (Consumer external antennas typically use patch antennas.)

Some threads that will fill you in with some info on Gypsies:
GPS?
http://www.vftt.org/forums/showthread.php?t=6720
Owl's Head Bushwack
http://www.vftt.org/forums/showthread.php?t=7172
Which GPSS is best?
http://www.vftt.org/forums/showthread.php?t=11144

Also http://www.gpsinformation.net has a lot of good info.

Doug

Sorry Doug

You're just speculating with your experiment. If you knew for sure I would have thought you wouldn't have tried the experiment.

I won't give up my antenna cause you did an experiment like that.
I tried lashing the unit years ago to the top of my pack and still had bad reception. Not until I got into the external antennas after reading lots of data and user comparisons did I have better reception.

You don't have to have a piece of paper with a degrees stamped on it to figure things out. Don't get insulted by that but it's true.
Oh by the way I was reading GPS information.net years ago. I got my first GPS in 1995 and have used ones others have owned and had lorans before that. How about you?

 

[DougPaul]

You're just speculating with your experiment. If you knew for sure I would have thought you wouldn't have tried the experiment.

No speculation involved--the experiment was done to parallel the one that Mohamed performed. Its outcome was consistent with theory. Call it a demonstration if you prefer.

Doug