Problems With Gps Reception

[+5 HAPPY CAMPERS]

We are relatively new to Geocaching (20 caches as of today!), we have the Garmin Etrex Legend and we have reception problems when under tree cover. When we get close to the cache the GPS starts to flip out. It never gets to zero feet. A friend of mine has one of the new color models of Magellan and while we were caching together, mine was flipping out and hers was right on, in fact, it took us right to the cache. This is a very annoying problem. Is the problem with the quality of our GPS or do we have a setting wrong? We are going to be purchasing the map software soon maybe we should purchase a better unit with software included. Please advise!

5 Happy Campers

[+Tahoe Skier5000]

Unfortunately, you bought a GPS that is known for a weak antenna. When approaching a cache though, the GPS will never zero out. The accuracy of the thing itself prevents it from ever getting to zero feet. This includes all GPS receivers, not just the Legend. They are only so accurate.

 

You can try a couple of things: Hold the GPS flat in front of you; not at an angle or upside down or in your pocket. If that doesnt help, you may want to think about getting a GPS with a stronger antenna.

 

Also, dont use your GPS for direction when you get close to the cache. Just use your head and look for a spot that looks obvious. Good luck!

[+scott9282]

Happy campers, something else to consider when caching. GIGO. Garbage In, Garbage Out.

 

What I mean by that is this: whoever placed the cache was using a GPSr, their coordinates were probably off by a bit anyway, at least 10 feet, maybe more. Now your unit, even if it's operating perfectly will only be so accurate, as the poster above stated. So if you're off by 10 feet, and the cache placer was off by 10 feet, you could have a 20 foot circle to deal with.

 

Better to get close, then start looking for likely places. That's part of the fun, trying to get inside the mind of the little maniac who hid the cache in the first place.

[+OldTimeRadioAddict]

We are relatively new to Geocaching (20 caches as of today!), we have the Garmin Etrex Legend and we have reception problems when under tree cover.  When we get close to the cache the GPS starts to flip out.  It never gets to zero feet.  A friend of mine has one of the new color models of Magellan and while we were caching together, mine was flipping out and hers was right on, in fact, it took us right to the cache.  This is a very annoying problem.  Is the problem with the quality of our GPS or do we have a setting wrong?  We are going to be purchasing the map software soon maybe we should purchase a better unit with software included.  Please advise!

5 Happy Campers

I just bought this same unit, and have noticed similar issues. However, I've only had these problems in HEAVY canopy on an overcast day.

 

On sunny days, even in medium-heavy canopy, the Garmin eTrex Legend is spot on. Well, like the other posters said, until you get within 10 feet of the navpoint. As they said, it is to be expected to have some exact waypoint issues. To be honest, when the Garmin leads me directly to the cache (within 1 foot) I get alittle disappointed that it took the fun out of discovering the hidden cache on my own.

 

Overall, I got what I paid for ($160), and it works quite well.

 

OTRA

Edited August 9, 2005 by OldTimeRadioAddict

[+EraSeek]

However, I've only had these problems in HEAVY canopy on an overcast day.

 

On sunny days, even in medium-heavy canopy, the Garmin eTrex Legend is spot on.

Sorry, this is just NOT true. It is satellite geometry, ionospheric distrubance, and multipathing which causes problems. Not clouds or rain or snow or fog. If you have excesive multipathing as in canopy some units will dump some sat signals, so it may be worse reception of the unit or just the firmware that is in the unit or both.

 

"Cloud, Rain, Snow, weather in general does NOT attenuate the GPS signals enough to effect accuracy. As can be seen below, the total atmospheric loss (from all causes including rain, clouds, snow, fog, etc.) is but 2db. This is small compared with other variables.

 

L1 and L2 Navigation satellite Signal Power Budget

 

Parameter L1 P-Code L1 C/A-Code L2 P-Code

-----------------------------------------------------------------------------------------------------

User minimum received power -163.0 dBw -160.0 dBw -166.0 dBw

Users linear antenna gain 3.0 dB 3.0 dB 3.0 dB

Free-space propagation loss 184.4 dB 184.4 dB 182.3 dB

Total atmospheric loss 2.0 dB 2.0 dB 2.0 dB

Polarization mismatch loss 3.4 dB 3.4 dB 4.4 dB

Required satellite EIRP +23.8 dBw +26.8 dBw +19.7 dBw

Satellite Antenna gain at 14.3° 13.5 dB 13.4 dB 11.5 dB

worst case Block II off-axis angle

Required minimum satellite antenna +10.3 dBw +13.4 dBw +8.2 dBw

Input power 10.72W 21.88W 6.61W

 

"

[Team Aardvark]

Hi

 

I have had a Etrex Legend for over 12 months and was disappointed with the sensitivity of the antenna particularly under moderate to heavy tree cover. Finally I brought a Etrex Vista C and tested both units head to head. The Vista C based on the testing (& in my humble opinion) has a significantly improved antenna and much quicker processing of the signal. I would rate its capability under moderate to heavy tree cover as very good and the Legend as satisfactory only under light tree cover. This is based on Australian bush conditions.

 

The Vista C is a top unit and I highly recommend it.

 

Regards team aardvark

[+5 HAPPY CAMPERS]

Thanks for all of your help! It is great to talk to others that are having or had similar problems. I realize the GPS will not take me directly to the cache and I don't really want that. However, being on the correct side of the trail would be nice. We get frustrated when when we are hot on the trail fo a cache and the numbers are going down, you get to 10 feet, etc then all of a sudden the compass starts to spin and it tells you to go 40 feet in the other direction, then when you do that it sends me in another direction. Sometimes, I am convinced that a maniac is controlling those satelites and is playing games with us while we cache!!! (Kind of like the man behind the curtain!)

Dawn of the 5 Happy Campers

[+Miragee]

If you are in an area where the signal is a bit better, even if you are 80 feet away, look at which direction the arrow is pointing and estimate the distance. Then start your search from that point.

 

If you still have no luck, move to another area where you might get a better signal and check the direction of the arrow and estimate the point for the distance the GPSr provides.

 

This technique should help your searches.

[Footpounds]

This is a little bit off topic but it looked like a good place to ask this re: Etrex Legend. When I save a Track, then go to that Track to look at it, there is a box near the bottom of the screen that says "Show On Map". You can check or uncheck this box. What does "Show On Map" mean? I check and uncheck it but I can't see any difference. Thanks in advance.

[+hogrod]

back on topic, just wanted to say i recently bought the newer legend C and it does get way better signal under heavy tree cover. the original B&W one would loose signal quite often in the same place. the legend C does require you to hold it correctly like the original...... screen toward the sky. you will loose signal if you try to keep in your pocket of around your neck. other than that i am impressed with the improvements!

[+Miragee]

I've never saved a track on the unit. It is my understanding that you lose some of the data. Consequently, I'm not familiar with that function, although it sounds like it will show that track, as opposed to your current track, on the map screen.

 

I download the tracks from my unit to the Mapsource maps. On the computer I can save sections of tracks and copy and paste them and upload them to sites like Magnalogs.

[peter]

What does "Show On Map" mean? I check and uncheck it but I can't see any difference.

If the box is checked, then that track will appear as a gray line (on the b&w models) on the regular map page. Otherwise it'll only show on the map that's shown directly from the Tracks page, but not when you're looking at the regular map page while navigating.

 

I use some of the Saved Tracks to show local bike paths and always check that box so I can see where they are while I'm out on bike rides.

[MRBTDumont]

I have the same unit which I purchased about 4 months ago.

I can have great signal in an open field but as soon as I get under cover I lose reception. After some research prior to purchase I was under the assumption that this was a respectable unit, now I am quite disappointed. Is there a modification or perhaps an alternate antenna that might improve performance at all?

Thanks

[+IVxIV]

Is there a modification or perhaps an alternate antenna that might improve performance at all?

Thanks

I doubt there's anything you can do to the GPS unit itself, the B&W Etrexes just have a poor antenna, and/or is supersensitive to how it's held

 

One thing you might consider though is to use a re-radiating antenna (scroll down that page) maybe something like that might give the little guy a boost.

[+5 HAPPY CAMPERS]

I have the same unit which I purchased about 4 months ago. 

I can have great signal in an open field but as soon as I get under cover I lose reception.  After some research prior to purchase I was under the assumption that this was a respectable unit, now I am quite disappointed.  Is there a modification or perhaps an alternate antenna that might improve performance at all?

Thanks

This is the exact same issue we ran into. We did a lot of research before purchasing the Etrex legend. It's very frustrating! It's not like its a bottom of the line unit! Thank you for phrasing your frustrations so clearly. That is exactly what I was trying to convey in my posts.

Dawn

1 of the 5 Happy Campers

[Team Sidewinder]

I have the same unit which I purchased about 4 months ago. 

I can have great signal in an open field but as soon as I get under cover I lose reception.  After some research prior to purchase I was under the assumption that this was a respectable unit, now I am quite disappointed.  Is there a modification or perhaps an alternate antenna that might improve performance at all?

Thanks

This is the exact same issue we ran into. We did a lot of research before purchasing the Etrex legend. It's very frustrating! It's not like its a bottom of the line unit! Thank you for phrasing your frustrations so clearly. That is exactly what I was trying to convey in my posts.

Dawn

1 of the 5 Happy Campers

My wife has the cheap old Garmin yellow etrex and I have the Garmin expensive 76CS. She has never failed to find a cache that I have found and there have been a couple of times she was right on and I was still wandering around while she stood there with this big grin on her face. This has been in various stages of tree cover and cloud cover. Save your money and just live with the gps you have. Enjoy the hunt.

[kf4hrm]

GEO VISTA EXTREX same crappe , little antenna with high cloud cover means trashy results. Sometimes your eyes and brain are smarter that any stuip box that eats batteries. Sometimes it may take 2 or 3 visists to find some micros

[+EraSeek]

GEO VISTA EXTREX same crappe , little antenna with high cloud cover means trashy results. Sometimes your eyes and brain are smarter that any stuip box that eats batteries. Sometimes it may take 2 or 3 visists to find some micros

little antenna Yes,

high cloud cover means trashy results NO!