Etrex 30 vs. GPSMap 62s

[+TFulton42]

Hi folks,

 

I apologize if this is already in a thread. Just point me to it if there is one.

 

I'm considering buying my 1st GPS for Geocaching. I'm currently using my iPhone, but want to upgrade. I'm looking at the Garmin Etrex 30 and the GPSMap 62s. The GPSMap is about $100 more and I'm wondering if the money is worth it. It seems like the big difference is the Quad helix antenna. How big a difference does that make?

 

Thanks for all of the help.

Tom

[seldom_sn]

The 62s also supports connections for an external antenna and a few more transfer protocols. Probably the biggest difference is in the buttons. The 62s permits forward and back menu selection. The Etrex just goes back. You can get a comparison here.

[tr_s]

I don't think an eTrex with Glonass will beat a 62s in accuracy - the antenna on that one is simply so much larger. More energy fed into the receiver from the start.

 

Tfulton42 unless you are uncomfortable with the bigger size I'd get the 62s any day. The firmware in the eTrex 20/30 series simply leaves much to be desired... bugs bugs bugs

[+Redwoods Mtn Biker]

I find the 62s a bit more user friendly, due to more buttons, their layout and button labeling. It's also easier for me to use mountain biking as I can toggle pages pretty well without looking at it.

[RamblinBear]

I compared my Etrex 30 (with GLONASS and WAAS enabled) with my GPSMap 60CSx out in the field just the other day. As those who've used GPS for any length of time will know, the 60CSx was pretty much the Gold Standard for accuracy and sensitivity in consumer GPS units in its day - and it's still pretty handy now. It's the predecessor to the GPSMap 62.

 

What I can report is that my Etrex 30 got a fix faster and with better signal strength than the 60CSx (despite the 60CSx having a quad-helix antenna). The reported position coordinates were pretty much identical in an open sky setting, but when I moved into cover (trees, buildings) it was the Etrex 30 which held onto a satellite fix longer and with more satellites being used in the computation. Both receivers were about 3-4 metres adrift of the position coordinates produced by the Ashtech MobileMapper 100 (£2500-worth of professional grade GPS which I use for my work) which I was actually using (for my work) at the time. The MobileMapper has a quoted accuracy of better than 0.5 metres RMS when using WAAS in addition to the GPS and GLONASS signals.

 

For the money, the Etrex 30 (and 20) are pretty hard to beat. The firmware is still a bit buggy (it has got a lot better lately), but then that was also the case for the GPSMap 60Csx when it was introduced.

 

In terms of user interface, the 60CSx (and the newer 62) are perhaps a little easier to get into (more buttons) but the Etrex is pretty good - especially if your brain hasn't got used to using the 60CSx first.

[RamblinBear]

Oh, and just for the record, the £2500 Ashtech uses a patch antenna. Nothing inherently wrong with patch antennae, just different characteristics to quad-helix. What matters is how well the receiver circuitry in the GPS chip works in partnership with the chosen antenna.

[tr_s]

Good to hear Ramblinbear's story. What I found from anecdotal experience was that:

 

With GPS only, the eTrex 30 seems significantly less accurate than the eTrex H under significant canopy. I've never during the H's lifetime seen 15-20 meter discrepations when following previously recorded trails in the woods. Glonass enabled makes it more accurate than the H in the same conditions, but makes accuracy worse than using GPS-only in the open (not much but noticeable).

 

May seem like cheesy anecdotes but I think I've been using the two receivers enough to conclude that this is the way it apparently is, with my two devices anyway.

 

Isn't the greatest difference between an "industrial" and a "consumer/handheld" device that the industrial one has a much finer clock source?

[tr_s]

My hardware might well be dud - haven't checked the accuracy figure of other 20/30 devices, but just a thought, how dense canopy have you really used it under. In less dense forest the thing is probably just as good as the H, but hard to tell really.

[+BlackRose67]

Thanks for the info RamblinBear.

 

With my eTrex 20 with GPS & GLONASS enabled (f/w 2.70 & 2.80) , I've had the GPS zero out on me several times.

In one case it turned out I was actually standing on the micro cache.

[RamblinBear]

Isn't the greatest difference between an "industrial" and a "consumer/handheld" device that the industrial one has a much finer clock source?

 

Probably a combination of various factors. As I understand it, the clock sources are the GPS signals themselves (which is one of the really neat tricks that GPS performs), but there will be differences in accuracy in how the GPS receivers compare the timing signals between satellites, and in electronics, accuracy = cost (generally, with a logarithmic relationship)! It's also things like the antenna and algorithm design to mitigate against multipath signals. I'm pretty certain the Ashtech also uses more accurate co-ordinate and grid transformations than the Garmins (not surprising given the cost difference). The OSTN2 transformation (WGS84 to OS National Grid) is actually performed in the particular software I use on the Ashtech. Sometime I'll have to compare the WGS84 outputs from my Garmins and the Ashtech and see how the errors divide up between the GPS receiver itself and the transformations to OSGB National Grid.

 

@ Sussamb, yeah, wet foliage is a killer, especially at this time of year (and with our weather recently) when the leaves are fat with water - thousands/millions of little flat ground-planes to reflect and disperse GPS radio signals all over the shop.

[snakyjake]

The quad helix antenna advantage is the reduction of multipath errors (canyons, tall buildings); and may receive better if you have the GPS under the car's roof.

 

I like the 62 because of a GPS camera. But I have another camera that I can use to perform that function.

I like the etrex for being small, excellent battery, and GLONASS.

 

I typically plan my trip in advance using large maps, and simply transfer reference data to a portable device. If I want a large map, I simply print one and carry it with me.

[seldom_sn]

The quad helix antenna advantage is the reduction of multipath errors (canyons, tall buildings);

Canyons are one of my main problems, and I find that I get serious multipath errors with my 62s and my 60CSX. Tracks can be as much as half a mile off.

This was from my 60CSX, but the 62s was no better. Hike is Angels Landing in Zion.

[+CarbonMech7]

I own both an Etrex 20 and the 62s... When im in my car I notice my Etrex 20 (GLONASS ON) has better accuracy than my 62s. The coordinates would not exactly match all the time either.. If i take GLONASS off on the Etrex 20... coordinates and accuracy will almost be identical to my 62s. I thought this 62s would have better accuracy in general than the Etex 20 but it didnt. Not only does it happen in my car, I find it different in the house, under big trees, in canyons and sometimes in open view to the sky. I guess i just have to keep testing both units out, a little disappointed Im not getting far better accuracy on my 62s more often than I should compared to the Etrex 20.

[+BAMBOOZLE]

As always, my vote is for the 62......wonderful button layout ( just like the 60 and Magellan Platinum).....I've never cared for the button layout and joystick arrangement of the Etrex line.

I've got a ton of GPS units and my Quad's always seem to outperform the Patches.