Keychain GPS usability?

Posted by: Keith

Keychain GPS usability? - 04/12/08 07:42 AM

http://mytreo.net/store/xproduct.php?xProd=489

Anyone know how the GPS functionality compares with other products? (I know that it requires another device to be useful. Some of us have those devices).
Posted by: phat

Re: Keychain GPS usability? - 04/12/08 08:38 AM

Which one? my biggest concern with all the micro sized units I've seen (watches, etc.) is both their ability to aquire and battery life, which is usualy pretty bad. I would take one a lot more often if reliable units with a decent run time were smaller..
Posted by: oldranger

Re: Keychain GPS usability? - 04/12/08 11:09 AM

My current preference for a smallish GPS is a Foretrex 101. Battery life is acceptable and the AAA batteries interchange with the batts in my lights and other gadgets. It holds a fix well enough in the terrain in which I use it. I haven't tried it in really dense forest cover. It has WAAS capability, which I have never used for real. This unit does not have a map, but I am comfortable transferring UTM coordinates to paper, the way in which I have always used a GPS in the field. Mostly it is light, handy, and heap plenty accurate enough for normal outdoors use.
Posted by: Keith

Re: Keychain GPS usability? - 04/12/08 12:18 PM

Quote:
Which one?


OOPS!! <img src="/forums/images/graemlins/tongue.gif" alt="" /> . . . . This one:
http://mytreo.net/store/xproduct.php?xProd=489
Posted by: Jimshaw

Re: Keychain GPS usability? - 04/12/08 08:40 PM

Keith
Technology exists to put a nice GPS in there, but the cost wold not be marketable so you can assume that every corner was cut even those cannot be cut, so most probably the antenna will function well enough inside a RF test box to pass, but its not gonna work under tree canopy hanging from your pack.
As phat pointed out - the battery is the kicker - how long will it last, how much does it cost, can it be replaced at all, can it be recharged, does it lose all memory when its replaced? I would assume the least cost invilving answer to each question. that is: <img src="/forums/images/graemlins/crazy.gif" alt="" />
not long, a lot, yes with a special tool, probably not, most likely yes.
So there you have it.
Jim <img src="/forums/images/graemlins/cool.gif" alt="" /> OR it might actually work - let us know. Start by trying it inside a metal file cabinet and see how far you have to open the drawer to aquire a signal. If it works in the closed drawer or slightly open - then it might work in a pack under trees.
<img src="/forums/images/graemlins/grin.gif" alt="" />Jim <img src="/forums/images/graemlins/cool.gif" alt="" />
Posted by: jshannon

Re: Keychain GPS usability? - 04/14/08 07:28 AM

Doubtful it is the latest chipset. I would not buy it.
Posted by: NiytOwl

Re: Keychain GPS usability? - 04/15/08 12:46 AM

I own a GPSlim240 which I've used in all sorts of hiking situations. The only times I don't get a lock are under overpasses, in tunnels, or in seriously tight box canyons (think Utah). Under virtually all forest canopy it still gives a position with a DOP of less than 5. This unit by Freedom appears to have specs that exceed mine, and a quick Google search of the user reviews for it seem to bear out that observation. The MTK chipset seems to be one of the latest and greatest - I'll go out on a limb and say that it should perform at least as well as any standalone GPS, and probably outperform all but the pro surveying models.

The only gripe I have about these bluetooth GPS devices is the battery life. I'm a breadcrumber - I like to see where I've hiked, how many miles I've gone, and be able to drop a waypoint when I stop to shoot pictures. 8-10 hours isn't much if you're doing this. If you use it more like a compass (turn it on, take a sighting and turn it off) then that should be sufficient. Otherwise you'll have to come up with a power cable or portable charger to use this on the trail. Be forewarned, some units cannot be charged and used at the same time! I had to mod the GPSlim240 because of that. The unit must now be plugged in to use it.

The nice part of going through this much trouble is a typical 800 mAh cell phone battery can power one of these GPS units for four 8-hour days. The Freedom GPS 2000 appears to use significantly more power though - it might only work for three days. If you take the trouble to build a high capacity LiPo power pack, it not only powers/charges your GPS, but also your PDA/Cell Phone and Camera/Camcorder. Using the GPS for 8 hours and the PDA for 12, I can stay out for a week before needing a charge.

Hope that helps with your decision.