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external antennas


buteo

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I own a Gilson for may Garmin GPSmap76 and it works GREAT! It's really nice for in the car... just stick it to the roof, wire it inside and hook it up, you get all 12 signals and most are as strong as it gets.for outside, it's not to handy, there really isn't a way to hold it and you GPS at the same time. I don't know of any good portable ones for carrying.

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I have a Gilsson for my 60csx. I makes a huge difference when driving. I've even taken it out into the field when tree cover was dropping my resolution down to 25 feet. I got back to 7ft accuracy with the antenna. For the small cost, they are great. I would recommend getting the 16 (or 18 I can't remember te exact size) cable. I got the standard 9ft, and it makes routing it through my car a bit difficult. You can always coil the excess and tuck it away.

 

SD

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Direct wired: two thumbs up - especially the "active" antennas that get their power from your GPsr. They are well worth the money for use in a car. Maximum benefit is had by putting the external antenna outside the car, not on the dash in the windshield area although this will still be an improvement over the internal antenna in most cases.

 

Those with some kind of wireless coupling gimmick: little chance of working at best. Nice theory, usually poor implementation, especially if homemade.

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I had several years experience with a CMT MCGPS. With this $5000 unit I used several different external antennas. The best of the ones that I used was called the "Mighty Mouse" which was an active with an MCX connector. The others that I used a 4 inch diameter mushroom shaped antenna with coax wire up to 12 feet long. This antenna could be used with a magnetic base or the screw on base that I mounted to my hard hat.

I also used these antennas with the Mighty Mouse taped on top of the larger antenna and mounted on top of a telescoping range pole. Before SA was turned off, I used GPS to determine the location of over 300 State Forest corners for a very large GIS.

If you have a GPS that has an external antenna port, I think you will be pleased if you get an active antenna and find a way to get it above your head.

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I was thinking about purchasing an external antenna for my garmin gpsmap 60c and wanted some feedback.

How well do they work and are they worth the investment.

What brands are better than others.

Any personal experiences would be appreciated.

 

I use a Garmin gpsmap 60csx with an external antenna that I ordered from Garmin. I keep it in my Camel Pack. It is on approx 6 ft cord but I leave the antenna in the pack & attach the cable to the GPSr. It is a life saver under heavy foliage.

Edited by Papafuz
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Direct wired: two thumbs up - especially the "active" antennas that get their power from your GPsr. They are well worth the money for use in a car. Maximum benefit is had by putting the external antenna outside the car, not on the dash in the windshield area although this will still be an improvement over the internal antenna in most cases.

 

Those with some kind of wireless coupling gimmick: little chance of working at best. Nice theory, usually poor implementation, especially if homemade.

 

This one works well. its not very expensive. The page shows the signal levels with and without the active antenna on. There is also a link to the one I built on that page. They work and well. If your GPS does not have a connection for an external antenna these will do a good job.

Edited by Michael
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Maybe that would have helped me when trying to get The Illusionist the other day. Quite possibly the most bizarre experience I've ever had caching. Could it be the magic aura of the area?
It's more likely that you happened to hit a hole in the satellite coverage. The sats are not in geo-stationary orbit. They constantly change position relative to the ground, and now and then there won't be any overhead. Two years ago I spent an hour with no lock at all, even on the roof of a tall building with nothing between me and the entire sky.
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Maybe that would have helped me when trying to get The Illusionist the other day. Quite possibly the most bizarre experience I've ever had caching. Could it be the magic aura of the area?
It's more likely that you happened to hit a hole in the satellite coverage. The sats are not in geo-stationary orbit. They constantly change position relative to the ground, and now and then there won't be any overhead. Two years ago I spent an hour with no lock at all, even on the roof of a tall building with nothing between me and the entire sky.

 

That's good to know! I'm gonna start using that on my DNF logs!

 

:D

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I have to question if it's really worth the price. I have a Garmin Legend Cx and have no problem getting sats in my cars. Granted, one is a ragtop, but the other is an SUV with sunroof. With either, top up, sunroof closed, sats are picked up very quickly and I have no problem with navigation. Sometimes I put the unit on the center console, other times in a windshield mount I bought (designed for a PDA, but the Garmin fits and holds just fine), and have never had a problem.

Just my 2 cents.

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My Magellan Meridian Color loves externals. Gets me from a lame five or so satellites to TEN full bars. I have two magnetic -- one's in the truck on the roof but the one I find most useful is the little one I have on top of my head. I use a little metal plate on the inside of my hat. It's got foam on the "head" side and nothing on the top. I attach the second external to that and it gets me TEN full bars penetrating cloud cover and triple canopy overhead.

 

Who said geocachers weren't propeller heads anyway? :rolleyes:

 

RATTLEBARS

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For the past three years, I have been conducting a GPS Accuracy Game at the Spring Flings and GeoLuau conducted by Shop99er. I have used a 76C which is the same as your 60C with first the Garmin external antenna and then the Gilsson antenna to set GZs. I have a fiberglass telescoping pole and set the antenna at 15 feet, wait until I get about 5 to 6 foot accuracy and then average for about 2000 hits and that will usually bring it down to about 2.5 feet. Now I have a new Etrex Vista HCx which I hope to use without the external antenna. I think it will be senstive enough to set GZ. After all it is just a game not surveying.

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Ditto what Rattlebars said - I have met several cachers that had an external antenna mounted on their hat.

 

If good reception is more important than looking somewhat geeky it is the way to go!

 

I was seriously considering one with my previous eight GPSrs, even for my Magellan Meridian Platinum.

 

Then I upgraded; with my Garmin GPSMap 60CSx I have never needed one...

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Just have one as a spare in the car, works on my Nuvii too as well as the 60CSx. Allows passenger to sit normal in the seat and not hold the GPS to the front window for best signal coverage. Is it necessary? No, but cheap insurance if the antenna craps out on either the Nuvii or the 60 CSx.

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I have a Garmin Etrex H and have not had a poblem with geting a signal or getting within 10ft. of a cache. Would an external antenna make a big difference?

It depends entirely on where you are looking for a cache. If there is heavy tree cover or if you are near a building that blocks signals, the chances are that an external antenna will get a better signal than your H.

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I have a Garmin Etrex H and have not had a poblem with geting a signal or getting within 10ft. of a cache. Would an external antenna make a big difference?

No

If you are consistently getting within 10 feet of caches you are on a roll!

Would they be any easier to find if you got within +- 1mm?

 

One thing to keep in mind about accuracy is that you can have coordinates accurate enough to discern between the right front and left rear leg of a squished gnat and if the person that placed the cache only got 4 sats the day they placed it then you are not any better off.

 

Generally an external antenna is going to improve reliability- defined as the ability to get consistently accurate readings. It will not improve accuracy unless the internal antenna has poor reception.

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I have a Garmin Etrex H and have not had a poblem with geting a signal or getting within 10ft. of a cache. Would an external antenna make a big difference?

No

If you are consistently getting within 10 feet of caches you are on a roll!

Would they be any easier to find if you got within +- 1mm?

 

One thing to keep in mind about accuracy is that you can have coordinates accurate enough to discern between the right front and left rear leg of a squished gnat and if the person that placed the cache only got 4 sats the day they placed it then you are not any better off.

 

Generally an external antenna is going to improve reliability- defined as the ability to get consistently accurate readings. It will not improve accuracy unless the internal antenna has poor reception.

 

Third rule of geocaching: When in doubt, look for the un-natural pile of sticks or rocks.

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Ever since trading my GPSMap 60CS for the GPSMap 60CSx I have not had to use my external antenna.

 

The Garmin "x" series has the SiRF III chip which provides unusual sensitivity to receiving the satellite signals under all sorts of cover, so I can't imagine ever needing an external antenna with one of those.

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Ever since trading my GPSMap 60CS for the GPSMap 60CSx I have not had to use my external antenna.

 

The Garmin "x" series has the SiRF III chip which provides unusual sensitivity to receiving the satellite signals under all sorts of cover, so I can't imagine ever needing an external antenna with one of those.

 

I can't either. I'll have mine inside my mixer, INSIDE the shop, and it still keeps a decent lock.

And as the picture shows, that drum is much more substantial than any tree cover.

 

DCP_32141.jpg

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Yes, the 60csx is great at holfing the signal lock. Now, what about when you are in less than ideal areas and you want more than 30-50 foot accuracy? The amplified externals will get you back to "normal" accuracy levels. Great for in the vehicle, or under heavy foliage canopy or urban canyons.

 

Do you NEED it? Maybe, maybe not. Can it help out ALOT in some circumstances? You betcha

 

SD

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