Sat. Navigators

Hi all, I have a TOM TOM 700 in my Disco 3 which has heated front windscreen. Sat nav systems advise you use an external aerial attached because the satellite signal may be blanked by heated screen. I have my external aerial sitting on the flat part part of the dash. Has anyone else found they get a better signal if the aerial is attached somewhere else?
By the way, this system is fantastic and very accurate (but it does take a few minutes to get an active gps signal)

Heated screens can have a detrimental effect to signals, but not as much as they say.

I use TOM TOM but its on my mobile phone, and i use an external GPS receiver that sits on my dash, with no external aerial whatsoever. Its got me round the country no problem.

Maybe i should have clarified. Tom Tom like other 'standalone' satnavs , have their own internal aerial. They say you need an extra 'external' aerial which i have, and like Lenny1969 this external aerial sits on the dash. But it can still take sometimes 5 minutes to get a verifiable signal. I can move this external aerial because it has a generous 10' (at least) of cable. My question is, does any other user (with a heated screen) find they have to put the aerial elsewhere or is the front of the dash just the same. I realise i could move the aerial about and see what signal I get, but there are many other factors involved (including the actual position of my car!) so any other input would be appreciated.

What i was saying is i dont have an external aerial, my GPS receiver sits on the dash and uses its own internal aerial. I can purchase an external glass mounted aerial if i want to, but as ive had no problems i dont see the need.

The warm up time for the signal can vary considerably on mine, from 60 secs to 5 minutes. But usually its on within 30 seconds.
My previous car had a heated screen and it didnt seem to make much, if any, difference.

I cellotape a map to the windscreen, ready in 1 second!!!!

To be honest ive never wanted a GPS system in my car, they are more widely stolen than cd players now.

But putting tomtom on my mobile phone was a stroke of genius i think.

i use a tom tom with the internal aerial. never really any problems. start up from seconds to 5 minutes in rare cases. tried some of the others and TT is the best value for money.

really funny to watch my (scouse) son in law arguing with it!



man and machine in perfect harmoney eh?

The satelites the GPS use are all on the horizon and not straight up, so if you are in a built up area or a mountainus area then it will be slow to start as it needs a minimum of 3 satelites to work out where you are.

Also if you turn it off and don't use it for a while and then start it up somewhere different, then it will take longer to initalize.

Recently got off a plane into a hire van in Geneva having flown from heathrow, put in post code of swiss hotel resort and had best part of 10 minutes of sat nav telling us to come off the M4 at Junction 4B and take the M25 heading south, giving us plenty of time to get lost (without maps) before figuring it out.

Heated screens can (but not always) stop the gps signals. Something about a Faraday cage. http://en.wikipedia.org/wiki/Faraday_cage This applies to the units aerial, as well as an external aerial. If you mount the aerial out side the car you'll see an improvement. I have a Garmin GPS60cs. I get about half the accuracy using it on the dashboard as I get outside the car or with an external aerial.

i have a tom tom 300 and a heated screen no problems whatsoever and no external arieal