REVIEW COMMENTS: GlobalSat BT308 GPS

MikeB · Last edited by MikeB on Thu Oct 06, 2005 11:35 pm; edited 1 time in total

Please post any comments you have regarding the GlobalSat BT308 GPS receiver review in this message.<br>
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The review article can be read here
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Mike Barrett

freeway680

thanks for an excellent review. I orderred mine this morning for $170 with 10% discount from gpspassion.

ocio · Occasional Visitor Joined: Jan 08, 2004 Posts: 10

mike b has written in the final part of its article : <>

are these problems fixed now ?

rascals · Occasional Visitor Joined: Apr 19, 2004 Posts: 3

You write:

DavidW · Posted: Mon May 10, 2004 7:16 pm Post subject:

I would expect devices like iPAQ chargers to be constant voltage rather than constant current power supplies. Putting it another way, I have never yet come across a piece of small IT equipment with a constant current charger or power supply. Such constant current supplies are only usually used to charge batteries directly.

In a constant voltage scenario, the charging circuit of the GPS should only draw the current it wants - and it should be happy so long as you got the polarity correct (reverse polarity does tend to destroy devices). Assuming it's not a constant current setup, which I very much doubt, using a power supply that has spare current capacity won't somehow force excessive current through devices and destroy them. Indeed, the spare extra capacity should provide better regulation.

However, problems can come if you don't put enough load on a power supply. Depending on the power supply circuitry, insufficient load may either stop the power supply from working effectively (especially if the supply is a 'switch mode' design) or mean the supply voltage goes high and out of specification. Both these could potentially mean damage for a small device like a GPS connected to a relatively high current supply like an iPAQ charger, though I can't comment on specifics.

Does anyone know of a PC power supply that you have to adjust according to the number of connected devices? I've certainly never come across one. The Dell Precision 650 workstation I'm using right now has a pretty big supply (460W from memory). So long as there's a minimum load on the supply so that it regulates properly (which, in practice, means there's a motherboard and at least one processor connected), the supply is fine so long as the individual voltage rail limits and the overall supply limit aren't exceeded.

Just because I've got this big power supply doesn't mean that if I reduced the three hard discs, two DVD drives and one tape drive in the Precision to one hard disc and nothing else that somehow more current would be forced through the remaining components, damaging them.

However, if I faked up the signals that the motherboard provides to switch the supply on and keep it on without providing the kind of loads on the various rails that the motherboard and at least one processor does, I may find the supply produces out of specification voltages that could damage connected equipment.

David

joschan99 · Occasional Visitor Joined: Jul 24, 2004 Posts: 1

Hi, Mike,

You mentiond in your review "When switching from NMEA to SiRF mode using a 3rd party utility it is important that the BAUD rate is set to NMEA 38400 when switching back. If this is not the case then the internal communications link between the Bluetooth module and the GPS Engine will be broken. Beware that this can happen "unintentionally" by using an application such as TomTom and selecting SiRF mode.
To fix this problem the battery needs to be completely drained and the unit left switched on for 48 hours after. "

What are 3rd party utility? navigation mapping software?? how about TravRoute CoPilot ?

Your information would be most valuable.

Thank you.

donster22 · Occasional Visitor Joined: May 13, 2004 Posts: 18

hi

perhaps a bit of a newbie question but i am thinking of upgrading from globalsat's CF model.

does this bluetooth receiver need clear line of sight to get a satellite fix or will it work from you glovebox/pocket/rucsac?

thanks
donster

Steve999 · Posted: Mon Sep 06, 2004 12:48 pm Post subject:

Hi,

I use my 308 from inside the glovebox of my Mondeo with good results. I guess the test is - how much metal is between the glovebox and the sky? You need to take a look at where you plan to use it. If there is only mostly glass and plastic in the way, then you should have no problems. It also work well from inside the top of a rucsac.

I also use mine in a motorhome and it gives excellent results from a locker reading through a glassfibre roof with 2" of foam insulation.

Steve
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yokiz · Occasional Visitor Joined: Sep 22, 2004 Posts: 1

Can I use Battery Extender to charging the GPS?

Dave · Posted: Thu Sep 23, 2004 7:33 am Post subject:

In theory no reason why you can't providing the voltage and amps are correct then it should work. Most GPS's accept a PDA charger so likewise a battery extender should charge them unless they have a different power requirement or plug.

MadLoox · Occasional Visitor Joined: Nov 02, 2004 Posts: 5

Hi,

I just purchased a BT-308 and connected to my PocketLoox 600 using TT3 Navigator. TomTom BT worked fine, but the GlobalSat BT-308 can't hold the right position. It jumps around the area. I left it on for half an hour but no succes.
I tried the BT-308 in another car with an Ipaq 2210, same thing. Good sat-receiving but it keeps jumping around in the neighbourhood.

This is the second BT-308, the first had the same issue, never ok, and I sent it back after three days.

Can somebody please help out ??

I tried TT-GPS 3.07 also. Connects fine, but jumps around.

Madloox

Witgood · Occasional Visitor Joined: Apr 22, 2005 Posts: 1

A very interesting and helpful review. One item that is not covered, however, is the matter of this unit's compatibility/adaptability with other mapping systems and other parts of the globe. I gather that this Bluetooth GPS device is essentially the same as the free-standing Dell Bluetooth unit. Is the mapping software dedicated to Europe or North America, or another section of the earth, and therefore incapable of being altered, or are the GPS system and software able to be reconfigured to provide mapping of different parts of the world? Also, does it accept software other than what it comes with (e.g. MS Streets and Trips)? I've yet to encounter solid information or an authoritative response on these questions. Some say yes, some say no. If anyone has any information to share on the matter, I'd appreciate it. Maybe I'm wasting too much time barking up this particular tree, and should go for a different GPS system entirely that can accept other software and be adapted to different continents. Cheers.

earp · Occasional Visitor Joined: Jun 21, 2006 Posts: 1

i need to buy just this module.
Do u know where i can buy it?
Regards
earp

Cranky_Don · Occasional Visitor Joined: Jul 24, 2006 Posts: 2

Gday,
In your excellent review of the BT-308 you mentioned about the BT link stopping outputting data to the PPC and that Globalsat knew of the problem and were working on a fix.
Do you know if they have sorted this problem out yet and if so, how do fix/update my unit.
Many thanks, Don =)

MikeB · Posted: Mon Jul 24, 2006 8:27 am Post subject:

My unit was an early pre-production model and this issue was supposed to be fixed for the production runs.

If you have a problem you need to return your device either to Globalsat or their local dealers to see if you have the correct firmware release.
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