Tunnel handling could be better

BeatO · Posted: Fri Jul 07, 2006 11:28 am Post subject: Tunnel handling could be better

Hi M8s

I own my Quest 2 now for quite some time and have beed to different places without much problem, by car and by foot.

In my car, I've installed an external antenna (the magnetic one from Garmin) so that the Quest has got a good "view" of the sky.

As I'm living in Switzerland, which you might know has a lot of tunnels, even around and in the citys itself, this is a common situation for my Quest to handle. But there the problem begins.

When driving into a tunnel, the reception is lost, which itself is no problem at all. I've checked the GPS info screen and saw that the reception is lost within at most two to three seconds of entering a tunnel. Up to that time all is OK.
But then the problem is starting. Although the unit clearly lost all signals, it doesn't behave like that but the black pointer starts to move very fast forward, sometimes more than 1 km in three seconds, quite unreasonable, as the last speed known to the Quest2 was about 80km/h. After a few more seconds, normally about 8-10, the Quest2 finally announces that it lost receptions.
That situation is the one which is easier too handel. It gets worse when the Quest2 decides, which happens about 75% of the time, that it takes a bend away from the street, again with an amazing speed, crossing or using different roads in the proximity of the tunnel.
If you've got automatic rerouting enabled, which can be a quite good feature if you realy have to take an unexpected turn, in these situations, it gets worse and starts calculating and recalculating like crazy.

To finish the long storry, does anybody know to get the Quest to stop "moving" on after loosing reception?

BeatO

Border_Collie · Posted: Fri Jul 07, 2006 11:42 am Post subject:

BeatO · Posted: Fri Jul 07, 2006 11:57 am Post subject:

Hi Lost_Property

I've tried that one with the POI's, turned them of and additionally, as we can't delete them from the Quest, loaded just a single one to the Quest2, having the feature turned off as well. Did not improve the tunnel handling.

To the SD card, the Quest 2 doesn't have an SD card slot, all it's memory is internal one, so can't do anything there.

BeatO

Border_Collie · Posted: Fri Jul 07, 2006 12:07 pm Post subject:

Kritou · Posted: Fri Jul 07, 2006 4:18 pm Post subject:

Does it exhibit this behaviour when using the flip up antenna? I'm wondering if the more sensitive external antenna is sensing some spurious and confusing signals

BeatO · Posted: Fri Jul 07, 2006 4:42 pm Post subject:

Hi Kritou

I can't test with the internal flipup antenna, as my car has a coating on the windshield. Therefor I don't have reception (or close to none) without an external.

(I tried to run the Quest2 with just the flipup antenna and if you're in a very good position (no houses around and the like) and you don't move, there might be a lock. But generally, without the external antenna, I don't have any reception within the car).

So I guess, there should be no interference between those two. Do you think I should cover up the flipup antenna completely, say with aluminium foil, to make certain it can't receive anything? I mean, if I take a look at the GPS information screen, I can clearly see that after a couple of seconds all sats show no signal anymore.
BTW: It's quite unlikely that the flipup has any chance of receiving any more than the external antenna, as driving into a tunnel, the Quest goes in "first", the roof-mounted external antenna probably has "longer" view to the sky, if this matters at all.;-)

BeatO

Kritou · Posted: Fri Jul 07, 2006 5:01 pm Post subject:

There won't be any interference between the two antennae as the flip is disabled when the external antenna is plugged in

For the purposes of testing could you position the Quest at the rear non athermic coated window and see if the same happens. Obviously you will need the help of a passenger or another driver and unless you have a 12v outlet in the back the Quest will have to run on internal battery

BeatO · Posted: Fri Jul 07, 2006 11:40 pm Post subject:

Hi

I'll try that, but as I've got a car which has a nearly vertical back-window it hope I get enough signal in. It'll take a few days until I can test that I thing but I'll get back with the results when I've got them.

BeatO

elsinga · Regular Visitor Joined: May 14, 2005 Posts: 171

I saw the same behavior with my Quest 2, after losing reception... this time under tree coverage (as we don't have much tunnels here in the north of the Netherlands Smile

). Taking a turn (and losing reception since I didn't use an external antenna) and seeing the track go forward/straight on at amazing speed...
_________________
Robert Elsinga =8- )

GPS V FAQ Quest FAQ
Home @ N 52"55.812', E 05"51.509'

BeatO · Posted: Sat Jul 08, 2006 9:25 am Post subject:

Hi elsinga

So then it's most probably not the external (more sensitive) antenna causing the trouble, I quess.

It looks like the question still boils down to my initial post, is it somehow possible to get the Quest2 to stop "running" around after loosing reception.

Anybody with a good contact, perhaps to a developer, to Garmin?

BeatO

BTW: I'm off to a one-week-vacation, so won't check back here very fast.

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