RamblinBear

Yes, they can be used that way - with an additional bunch of kit - but that typically gets you into the 10-centimetre (or better) range of accuracy. That's more accuracy than I need in my work, and more cost than my employer would want to bear. The thing is, the basic data I'm working from isn't accurate to that level - so the extra precision form the receiver would be "wasted" in that application.

This is widely discussed in the world of wristwatches... Hesalite (perspex, acrylic) watch crystals are genuinely the toughest, even though they scratch quite easily. They are easily polished back to acceptible clarity, though. Toughened mineral glass (like Seiko's Hardlex) is the next toughest, and scratches less. Sapphire is the hardest and scratches least, but is more brittle and is the least forgiving of strong impacts. For this reason, most "serious" diving watches (rather than expensive Rolexes and Omegas) have thick (4mm or so) mineral glass crystals, which are an acceptable compromise between scratch resistance and toughness. You don't want to accidentally crack your watch crystal at depth - the watch would flood and stop in an instant. Sapphire might be a "premium" material, but it isn't always the most suitable. In the case of a GPS which may get bumped and dropped, clear polycarbonate resin, with a Zagg (other brands are avaialble) protector is probably a more effective and economical way to prroceed.

I don't know about WAAS ground stations (and I'd think it unlikely because we generally can't pick up the US WAAS signals this far east), but we have a few EGNOS ground stations here in the UK which feed into the EGNOS corrections which we can receive. The EGNOS ground stations are shown here... EGNOS Ground Segment

You don't need to post-process to get sub-metre accuracy these days - it's available in real time with a quality (not consumer-grade) GPS employing WAAS/EGNOS corrections. Many manufacturers produce them - Trimble, Ashtech, Topcon, Leica...

A very compelling argument. Allow me to retort. The Colorado, the Oregon, the nuvi, the eXplorist ALL receive the exact same signals, from the exact same satellites. It is physically impossible for the Colorado to 'get a better signal' than any other GPS. Mostly just old timers and fools believe the antique external helix antenna is superior to newer internal antenna designs. If that were the case, do you think all new GPS units would be without the external helix antenna (as they are)? Not to mention, newer GPS units also have access to 24 additional satellites (GLONASS) to more precisely and quickly pinpoint your exact location, all accomplished without external helix antenna. Hmmm... By this argument, my £180 Etrex 30 (which I use for hiking) would be just as accurate as my employer's £3500 Ashtech MobileMapper 100 (which I use for resolving legal disputes at work). Both pick up GPS, both pick up GLONASS, both pick up EGNOS correction signals, and both have internal patch antennae... ...but there the resemblance ends. The Etrex 30 isn't as accurate as the MobileMapper - not by a long way. The MobileMapper consistently achieves sub-metre accuracy - repeatable, day-in, day-out. With the Etrex, I'm lucky to get consistent 4-5 metre accuracy - still good, and more than adequate for hiking, but not for telling a landowner that their barn or excavation is in the wrong position. GPS receivers (despite their low cost) are incredibly complex devices, and there are a hell of a lot of variables and compromises involved in their design and production. There is no one "best" solution. Quad-helix antennae certainly used to be more sensitive than patch antennae, but the RF front-ends of GPS receivers are generally much more sensitive than they were a few years ago. Patch antennae are generally easier to package, cheaper and more robust than quad-helix, so they usually get the nod on low to mid-price units - the better RF front-end takes up the slack. Expensive, survey-grade GPS uses much more complex antenna designs to maximise sensitivity, improve multipath rejection, and selectivity. The same kind of gradings apply through the whole signal chain, the RF "radio" receiver, and the GNSS decoder and the algorithms it runs to compute a position. The more you pay, the better the tolerances in production, the more sophisiticated the hardware, and the more accurate and stable the firmware/software it runs. This does make a measurable difference - it's what people like me (or more accurately, my employer) pay (a lot) more for. When I compare my Etrex 30 with my older GPSMap 60CSx (both running the latest (non-beta) firmware, the tracklogs are remarkably similar (and I'd wager the Colorado (with the latest firmware and WAAS enabled) would give very similar tracklogs too. In my experience, the addition of GLONASS reception doesn't really give you much more in terms of accuracy, what it does give is more reliability and availability of signal in otherwise marginal reception conditions. What I'm saying in a roundabout way, is that any one feature doesn't necessarily make a GPS "better". The Colorado in its day was a good unit, and it can still give good results. There are better units now available, but they're not as "better" as some would have you believe. I'd suggest you take some tips from some of the folks on here who have been able to get their Colorados to work well for them. If you try all that and give it some time and still can't make it work for you, then perhaps it will be time to upgrade (and in the meantime, the firmware on the latest units might have been ironed out a bit more).

Hi, and welcome. Such devices are available - but they ain't cheap. I work in managing public rights of way for a local authority in the UK. Our needs include being able to plot/locate public rights of way to the nearest metre accuracy. The device we use is an Ashtech MobileMapper 100, onto which we are able to load OS Mastermap data and our public rights of way datsets (which are all held on an ESRI ArcGIS corporate GIS system). The device is invaluable to our work and saves us a great deal of time and effort (and therefore money), but it does come at a cost - the handheld device alone costs about £3000, with software costs on top of that. I have no affiliation to them , but we bought our device from a company called Positioning Resources of Aberdeen, and get excellent backup and support from them. Google them, if you're interested, they have a website, and are also happy to talk to people on the phone.

It's not just about infringement of spectrum property - it's also about safety of life. Some of these devices have been documented as causing significant disturbance to GPS-assisted approach to busy airport runways - just for the sake of someone wanting to pull one over their employer. How is that a just balance between private and public interests? My employer has a policy of fitting GPS trackers to all its fleet vehicles - for a variety of good reasons, such as monitoring fleet deployment and availability, personal safety of operatives, and also monitoring compliance with mandatory highway speed limits. I don't have any problem with any of that - if I'm in my employer's vehicle, doing their business in time they're paying me for, it's legitimate. I don't have anything to hide. If I did find it that much of an issue to my personal liberties, the answer is very simple - I'd find a different employer.

Double post - sorry.

Um, LED's Actually, I think some of the older ones may have used small cold cathode fluorescent tubes, as did some of the early colour screen mobile phones. Cold cathode fluorescents have the dual disadvantages of being fragile and relatively power hungry.

I find a Q-tip or cotton bud dampened in spirit vinegar is often very good for removing goo from alkaline batteries - and used carefully it can clean up the battery contacts as well. I'm just wondering, did you leave the batteries in the unit when they were dead (or nearly so)?

Also, adding GLONASS reception isn't just about improving accuracy, it's also about improving the reliablity of your position fix. With GLONASS turned on, my Etrex 30 regularly gets a fix from 10 or more satellites - even in difficult locations where my GPSMap 60CSx struggles to get 4 or 5 satellites. It makes the difference between getting a good fix, and not getting a fix at all.

I had a refurbished 60CSx from Garmin a few months ago - it was as good as new.

In the UK, the support for Magellan is pretty poor - both in terms of maps and more general product support. Personally, I'd go for the Etrex... Hang on, I did... just a few months ago... :-)

Glad to be of service...

I think you'll find this isn't a defect, but is probably caused by having your device set to record the barometric trend even when turned off. I noticed this on mine. If you dig into the Altimeter settings in the Setup menu, and have Pressure Trending set to "Save Always" instead of "Save When Power On" it causes it to happen. At least, it does on mine... :-) What I think happens is that the unit has to power up very briefly in order to capture the barometer reading, and as it powers up you get the display flash thing going on. I found it a bit irritating so have set mine to "Save When Power On" unless I really need to know what the barometric pressure is up to. I'll be interested to know if this is the cause on your device - even if you didn't deliberately set it that way.

I find the compass on my etrex 30 pretty good - the only thing is it needs frequent calibration, like each time I turn it on (annoying but only takes 30 seconds or so). Regular recalibrations may fix your issues.

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.

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.

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.

I had this issue on my Etrex 30. Coming from a GPSMap 60CSx, I had set the USB mode to "Garmin", but actually the USB mode needs to be set to "Mass Storage". Once I'd done this the update worked like a charm.

Interesting... I loaded up the beta software today, which went OK. When the loader was installing the software into my device giving percentage progress, there was also a little message saying "programming region 14". I'm curious to know if there's any significance in this - whether any other users have had different regions come up on their devices? Also, this install wiped out my satellite info (had to re-acquire from scratch) and my compass calibration (first time I went to the compass page there was a message telling me to calibrate). Not had that before.

Using a handheld mobile phone whilst driving is banned here in the UK - and yet even so, people continue to drive whilst yakking away on their mobiles. I think there may be studies published which demonstrate that appropriate use of in-car GPS actually results in safer, more fuel-efficient driving.

I have the barometric altimeter active, as I find that if it's calibrated, it's generally the most accurate. On the 20, the VSI must run solely off the GNSS altitudes, so probably uses a different bit of code than when the VSI runs off the barometric alti on the 30. I will try it with the barometric alti turned off, but it kind of sticks in my craw a bit - I paid good money for the electronic alti, and I'm gonna use it....

When I'm out walking, I often like to have the vertical speed indication enabled on my GPS, but I've noticed that the display is a bit erratic on the Etrex 30. It's like there's a threshold speed below which it doesn't work properly. When I'm walking up or down moderate slopes, the vertical speed indicates 0.0 m/m most of the time, only very briefly flashing up a speed of a few metres/minute. Once I go faster (or the hill gets steeper) the display becomes constant and more meaningful and shows the rate of ascent/descent consistently. The threshold rate of ascent/descent seems to be about 6-7 metres/minute: below this the display is 0.0 m/m most of the time, above this speed it behaves properly giving a constant display of the rate of ascent/descent. I never used to have this issue with my GPSMap 60CSx, and it seems like Garmin have set the threshold a bit wrong in the firmware (might be OK for skydiving or hang-gliding). I'm using version 2.7. It's kind of annoying, and something I hope that Garmin will sort out given time and enough complaints. Has anyone else encountered this issue?

The Etrex 30 would make quite a nice all purpose (bike and walking/geocaching) unit and can accept heart and cadence sensor input. The Garmin handlebar mount is simple and effective. The Etrex display is easy enough to read in sunlight or overcast conditions too.