View Full Version : GPS advice please??
OK I've used GPS the odd time but never owned one. I've thought of getting one for a while to augment my compass (as magnetic compasses never get flat batteries). I've looked at the outdoor shops and online and in catalogues and I'm a bit confused. I don't want to be spending much more than £150 but the amout of units available is mind boggling, so what should I be looking for feature wise? The descriptions are often baffling and confusing. I tried to talk to one of the stallholders at the NEC outdoor show but he launched into his 'spiel' and for the 5 mins I was listening, he might well have been speaking russian. He sneered down his nose at me whilst taking great joy in bombarding me with 'technobabble' So I slowly sloped off and went to sit in the 'stupid corner' where I obviously belonged :?:
didnt you tell him you were a high priest of the Bushcrafti...?
maddave, I'm a big fan of Garmin, dunno why, I just think the etrex range is brilliant for outdoors work, they're small, light, waterproof, not too heavy on batteries, the controls are good even with gloves on and the screen is nice and clear.
It depends if you are after the ability to have maps on it or just as a way of measuring distance/bearing or retracing your steps...
Some people harp on about how many parallel channels blah blah blah but I have used mine a number of times, it's the most basic model and I think it's brilliant, has never let me down.
I have had a little poke around on ebay and found the following:
This is what I got but it's just a little cheaper than the price I paid.
If you want a play before you buy, I could post you mine perhaps... as long as you post it back :wink:
even with 17squid postage thats a good deal!
It's the same model as mine... I got a nice little od neoprene cover for it though...
I posted this earlier, but SOF in Chester have a cracking offer on Cobra GPS at the moment at about £80.
Its a little bigger than the Geko, but has 18 channels rather than 12, it has an electonic compass and altimeter too. To get a similar spec garmin you have to spend around £200.
Cobra are new to the GPS market but I have seen their name on two way radios and nightvision stuff...
What you can't do with this model is link it to a PC, but I don't think you want that anyway...
i have seen people with hand held GPS's mounted on their car dash boards... does this mean they have road maps too??
mine has an altimeter and compass... I don't know if they are "electronic" what's the diference and should I care?
p.s. Mine has never got me lost :wink:
tomtom I have a garmin StreetPilot III and it's not exactly hand held, it does have a nice colour screen and voice commands so it can tell me what turning to take etc... you can get GPS units for just about everything, including waterway specific for fishing, aircraft, driving or mountaineering.
I like my little etrex because it's none of the above, it just stops me from getting lost and can get me back to where I was in pea soup fog in the dead of night... but not in veahily built up areas or really heavily wooded ones.
Accuracy is typically 30 feet which is enough to see whatever feature you're after.
Some early GPS like my Garmin 12 don't have a proper "compass", but something they call a "direction of travel arrow". What that means in practice is that it tells you what direction you are moving in...ie you must be moving for it to work..this was really nothing more than a calculation based on the data from the Satilites. Stand still and face different directions, and you would not get a proper reading. Basically they are a pain in the bum to use!
Later GPS had a proper electronic compass stuffed into them which worked independant of the GPS data and was a "proper" compass...much better to use but they tend to draw quite a bit of battery power. However not all electronic compasses are equal either! the first versions of this needed the GPS to be kept horizontal to get a true reading (like an ordinary compass) while the very latest (ie more expensive) can cope with a larger degree of "tilt".
With regards the atlimeter, historically the most inaccurate measurement on a GPS was the height reading..I am not sure way, but it was..Things got better when they went to 12 channels, but it is still far less accurate than your "ground fix". To get round this, companies have added a seperate electronic altimeter function which basically is a fancy barometer. I am not sure exactly how it intergrates the information with the GPS reading, but the result is a more accurate height/3D fix...Again the down side is that it consumes more power which is a real issue with GPS at the moment.
But isn't the problem, with commercial GPS's, is that they don't work in bad weather( doesn't link-up with the sattilite)???? :?:
Not only can you have street maps on a GPS but you can also get standard OS maps too. Many will even intergrate with your PC and special mapping software which will allow you to plan your route on a 3D map on your PC and then down load it to your GPS...or if you go for a walk somewhere and store the route on your GPS, you can upload it onto your PC and display it on your mapping software...All this is very expensive stuff though...
The other reason who see GPS mounted on the dashboard is so that the antenna can see the sky! Being in a "metal box" can degrade the signals in some cases...GPS systems that are designed to be fitted in cars permanently have what amounts to a proper external antenna of some sort to get around this..
I have never noticed the weather being an issue but the GPS needs to be able to "see the sky" so to speak. This means that if you are in a steep sided valley or under heavy forest canopy, sometimes you don't get strong signals from enough different satilites to give you an accurate fix. This was a major problem with very early GPS but these days with modern 12 Channel recievers they are a lot better.
If there is a problem, you can tell by looking at the display as you don't get many satilites "locking on"...some GPS will flash a warning saying "poor coverage" or similar...
mine was one of the original Magellans. One cloud in the sky and forget it!!! Back to the compass and map!!!! :***:
my little etrex is a 12 channel gps... I've used it in truely miserable weather and no problems.
The early Magellans seemed to have a bad reputation for poor lock on's in general...The garmins struggled a bit but seemed to come of age when they brought out the Garmin12. Do you know how many channels it worked off? I seem to think the very earliest ones were only 2 channel!
Now that the Americans have switched off the deliberate error on the civillian GPS system, most of the major brands are very accurate. This is especially true for the new generation with enhanced accuracy (WAAS enabled is the term they use) and this can give an average accuracy down to 2m or 3m in many cases. Mind blowing stuff, but they all still eat batteries at an alarming rate though!
I have been using a Garmin GPS12XL for about 8 years, it has been reliable in all weather conditions and in most types of terrain (limited coverage without a remote antenna in jungle conditions).
I have used some of the older Magellan's and was not impressed with them, but the Garmins tha6t I have used have all been pretty good.
It sounds like you can already navigate well with map and compass and like myself just want a GPS as a means of fixing your location. At the moment i use a garmin Venture for just that. In general you dont need any of the fancy functions unless you want to use the map software for points of interest around town and that sort of thing. I have used mine a couple of times to plot a route but the drain on the batteries over 8 hours in the hills is pretty high, i am lucky if i get 6 hours out of mine.
Having said that they are great for fixxing your position. I would not get into the situation where you are relying solely on your GPS as mine has recent developed a fault whereby it wont pick up any satellites and you have to perform a factory reset on the unit by pressing all the buttons together in order to get it to work again. This of course wipes all the data stored on the GPS. This has happened a number of times and i may have to return the unit to Garmin, it is outside warranty and i dread to think how much the repair will cost.
If you get a GPS dont forget your map and compass skills.
Hope this helps
It really all depends on what you want Maddave ... if you just want a GPS that gives you your position then you can get one for about 70 + VAT + PP ... these will be the basic eTrex yellow or the Geko 101. Both good units and both reliable and accurate. If you want greater accuracy through WAAS (Wide Area Augmentation System) then be prepared to pay up to 150 notes. For this you'll get something like the Geko 301
The earlier units were single channel (they could only listen to 1 sat at a time), now almost all are 12 channel with 14 channel receivers on the market. Good 14 channel receiver is the Magellan eXplorist 200 or 300.
Accuracy and sat lock under most weather conditions is excellent although rain or high moisture in the air can reduce the signal strength but the real nemesis is trees, especially pine trees because the needles contain water and are also ideal microwave antenna and actually absorb the signal (the signal from a GPS sat is the equivalent of seeing a 25 watt bulb from 20,000 miles) so really it's quite amazing that we pick it up at all.
If you need more info Maddave, either give me a holler on the forum or via PM.
Thanks for all the clear advice guys..Given me a lot to think about :You_Rock_