GPS Forum

[noddydog]

I am currently running tomtom 5 Nav on an Ipaq 4150. I would like to buy a bluetooth GPS and use this rather than my current hardwired set up (with Garmin Etrex).

This is all new territory for me. I've seen various units on eBay but haven't a clue what I should be looking for. For example is a 32 channel unit worth it? I've seen the blurb refer to Fujitsu Japanese chipset and SIRF III, which one is best? Some can be used for upto 30 hours, others for only 10. How important is this in reality. Finally some of the units have an 'auto off' function (i.e. they switch themselves on and off depending on the state of the car engine'.

Could someone please tell me what are the most important features to look out for in reality. Also feel free to suggest some specific models.

Many thanks in advance.

Nigel.

[noddydog]

Anyone please!

[alanterry]

Hi,

You may get, or find, answers more quickly on the much larger pocketgpsworld forum. However, here are a few comments:

Most modern Bluetooth GPSs will probably give better reception (in difficult conditions) than the fairly aged Garmin designs. However, the SiRFstar3 chipsets are widely considered to be the best available at the moment (and Garmin are using them in their top-of-the-line Handhelds).

There are rarely more than 12 satellites "visible" at any time, so more channels are generally unnecessary. There *are* methods of using more channels (e.g. for indirect signals bounced off buildings) but these techniques are unlikely to be used by a "cheapie" GPS off eBay. 32 channels are probably just playing the "numbers game".

7-15 hours are typical running times (depending partly on the size of the battery fitted) and 30 hours is probably a manufacturer's (or advertiser's) figure that bears little relationship to "real" use. You must decide how long you *need* it to run without external power.

"Auto off" normally means that the GPS turns itself off when Bluetooth communications finish (i.e. after the PDA is switched off) to save the battery. But there is no equivalent "Auto on" because the Bluetooth receiver is no longer "listening". Some GPSs thus use a push-button to switch the GPS back on.

Others (like the Holux 236) have a simple mechanical slide-switch to turn them on and off. However, if you simply power them via the car "ignition switch" (usually the car cigar lighter socket) then the GPS will continue running from its internal battery until that goes goes flat. Not very useful as the GPS will then take longer to start next time (because the time and satellite data will have been lost). Therefore, some people wire their GPS to run 24/7 from the car battery, but it's not clear if this may affect the long-term reliability.

Personally, I bought a Holux from Nav4All, but it's only an OEM pack (no CD, manual or mains charger) and I had some hassle as the firmware wasn't the latest version. There's a lot to be said for buying a "genuine UK" version; one of the cheapest suppliers being Clove Technology.

Cheers, Alan

[noddydog]

You are a star. Thank you for the time you spent in answering. I really do appreciate it. That helps me out a lot, at least I know what features I should seriously be considering and also not to buy a clone.

Thanks.

Nigel.