intermittently losing satelitte signals..

[inlikeflynn]

I've had a tomtom for years now, and replaced my stolen one last year, with a new XL v1 for the uk. everything was fine until it started to suddenly lose the satelitte signal showing ''waiting for a valid gps signal'' every now and again.This became more of an inconvenience as I'm a mobile engineer, and need to find places fast and accurately. I thought that it might have been the unit as I'd had it over 18 months, and so bought another of the same type, as I use my tomtom all over the world, including the US, and need the sd card expansion slot at the bottom. Imagine my horror to find that that the same thing is happening to my new unit, so I set up an experiment. I took both the tomtoms out with me simultaneously setting the addresses of where I'd want to go. Both units seem to go out of connection with the satellites at the same time, for approximately the same length of time, even in clear skies! Has anybody got any ideas? Are the satelites starting to fail? has TomTom come up with any answers? I await any thoughts and comments as to what people have experienced or know about this problem.Thanks for all your help.

 

[canderson]

Both units seem to go out of connection with the satellites at the same time, for approximately the same length of time, even in clear skies! Has anybody got any ideas?

Are you familiar with the GPS jammers that some truckers and other 'road' employees have started using? Illegal, but commonly available from several online sources from China. We've had such problems with them on one of our motorways near Newark Airport that they've been causing problems with GPS landing approaches.

I haven't heard that the UK has been playing any games, but we have had a couple of 'jamming' tests by the military here in the U.S. this year that whacked reception pretty good. That's another option.

The fact that both of your units fail concurrently points to an external RF source killing your signal.

Are the satelites starting to fail?

Not recently - but they do have spares <g>.

has TomTom come up with any answers?

I doubt that they need any. Long odds against it being a unit issue, especially with a pair going blank in sync with one another.

 

[mikealder]

Had you updated or had the devices connected to TomTom Home prior to taking them out, it could be as simple as a duff qGPS file loaded to the units, this has happened before.

One other point when running multiple devices in the car don't have then right next to each other as they do cause interference with the GPS reception, as an example start both units outside and tap the sat strength meter followed by the smaller sat strength meter to get to the GPS status screen. with one unit in each hand move the devices closer together and you will see the SNR figures drop on both devices, move them appart and the SNR goes back up - Mike

 

[canderson]

Had you updated or had the devices connected to TomTom Home prior to taking them out, it could be as simple as a duff qGPS file loaded to the units, this has happened before.

That could certainly cause an inability to acquire, but shouldn't cause two units that have already succeeded in acquiring a lock to simultaneously lose satellite reception.

One other point when running multiple devices in the car don't have then right next to each other as they do cause interference with the GPS reception

Are some units more prone to this than others? (I'm guessing you've had reason to know this better than most of us). During various tests, I've had a 720 and 740 side by side, and while it does have a minor impact on signal strength, I've never had units drop contact altogether in tandem.

 

[inlikeflynn]

As I recently bought another unit to replace my 'failing unit' I haven't connected them to Tomtom home as yet. However I do have a tracking system in my van, and I'm wondering if this might have something to do with it. On saying that I work with a group of engineers who all have trackers in their vehicles, and they don't seem to be having the problems that I'm having. Thanks for your advice and help though.

 

[canderson]

As I recently bought another unit to replace my 'failing unit' I haven't connected them to Tomtom home as yet. However I do have a tracking system in my van, and I'm wondering if this might have something to do with it. On saying that I work with a group of engineers who all have trackers in their vehicles, and they don't seem to be having the problems that I'm having. Thanks for your advice and help though.

Yeah, well that jammer you put in to defeat your boss's tracker probably isn't helping

That is why the jammers are used. Assuming you didn't do something naughty yourself, are you by any chance in proximity to other vehicles in the fleet when these events occur??? Makes me wonder what your co-workers might be up to.

Another question -- does your tracker report data back to the 'home office' on an ongoing basis (RF transmission), or is the data just being recorded for later download? If the former, do you have any idea what frequency is being used for the transmission -- or even what tracker is being used?