TomTom TMC - Areas of Service / No Service

vicky · Posted: Fri Dec 29, 2006 1:44 pm Post subject:

OK

So now I am confused,

I have tried modding the Reciever following the supplied instructions.

1st attempt wired as shown in photos, result

No change, so deisconnected Car Charger from the TomTom, instantly got a signal from 100.1 and 101.1 Brilliant, never had that before!

Reconnected the Car Charger, lost signal.

2nd Attempt Wires revered Result as above

3rd Attempt connected core to core only no screen, same result

4th Attempt connected screen to core only, same result.

Where am I going wrong, it seems any attempt to connect the TT to power once the mod is done results in a total loss of reception, but whilst the car charger is disconnected Brilliant reception from multiple transmitters.!

Going to work soon so cannot play again till Saturday, but any ideas would be appreciated

Cheers

Vicky

MELennium · Posted: Fri Dec 29, 2006 7:03 pm Post subject:

Hi GizmoB73
Well done with your mod. Have you connected to your car antenna by using a splitter or have you installed a seperate antenna? Also have you still got the original Tomtom reciever & cable around your windscreen or is this not neccessary now that it is connected to the antenna?
_________________
TomTom Go 910 (3) v.6.522 Map Western Europe v.650 with useless TMC receiver
Ex. owner TomTom 910 (2) Returned Faulty
Ex. owner TomTom 910 (1) Returned Faulty
Ex. owner TomTom One v.5.420 Map UK v.605
Ex. owner Garmin i3 v.2.7 Map UK V.7

GizmoB73 · Posted: Fri Dec 29, 2006 7:23 pm Post subject:

The red wire that I have soldered in my photos, should be connected to the screen of the car antenna. The other wire goes to the core of the car antenna. (I know this is the reverse to what would be obvious) If you solder it the other way around (red to antenna core), you will lose the signal as soon as the car charger is plugged in.

With mine I have no signal in the car when the car antenna is disconnected but within a minute (usually) of connecting the car antenna it locks onto Classic FM and pretty quickly starts receiving traffic data.

To test this, I can just disconnect the antenna and manually choose another frequency such as 99.0MHz to start it scanning again. After a few cycles through the full range I get bored and plug the car antenna back in and without fail it gets a lock again.

As for the suggestion that these two pads are shorted together, I doubt it, otherwise why would it work with the red wire pad to the antenna shield but not the other way around? In fact if it were shorted, it shouldn't work at all when connected to the car antenna. How did you measure the short?

In my car I have a Carputer instead of a stereo, so my antenna was redundant until I plugged it into my TMC receiver. If you have a car stereo you can just a splitter cable. I don't like to have the cables routed all over the place so I have mine fed straight into the dash where it definitely won't pick up any signals. Even more reason to use the car antenna. Smile

MELennium · Posted: Fri Dec 29, 2006 7:28 pm Post subject:

GizmoB73 thanks for the quick reply.
_________________
TomTom Go 910 (3) v.6.522 Map Western Europe v.650 with useless TMC receiver
Ex. owner TomTom 910 (2) Returned Faulty
Ex. owner TomTom 910 (1) Returned Faulty
Ex. owner TomTom One v.5.420 Map UK v.605
Ex. owner Garmin i3 v.2.7 Map UK V.7

coastersteve · Posted: Fri Dec 29, 2006 10:11 pm Post subject:

coastersteve · Posted: Fri Dec 29, 2006 10:24 pm Post subject:

Sorry,

My only suggestion as to why Vicky's doesn't work with the power supply connected full stop is that the switching powersupply is noisy. MikeA told me this was an issue with the Garmin units.

Vicky, could you try removing the fuse and plugging the power supply in. This would give me a good idea as to whether its being shorted or power supply noise.

vicky · Posted: Fri Dec 29, 2006 11:16 pm Post subject:

Hi

Its not a noise problem, I get the no signal issue when the car charger is connected and the ignition is off (I have a switched Lighter socket), so its dead with the ignition off and I still get the no signal issue,.

I am going to sit out in the car for a bit now and re solder my lead again see if I can get a result, Just in case there is a fault on the coax link I am using I am going to resolder it with a new link lead!

GizmoB73 · Posted: Fri Dec 29, 2006 11:24 pm Post subject:

I guess there must be an inductor across those two pads. That would explain the DC short, and is probably there for impedance matching to a 75 Ohm load at 100MHz. I have an antenna on my TV that has the same sort of thing built-in.

I am not an expert on switchmode power supplies, but removing the fuse won't work if it uses a common ground between the input and output as the earth ground would still be in-tact with the fuse removed. That would also explain why the problem still exists with the ignition off (on a switched cigarette adapter).

My bet would still be that you have the wrong pad connected to the antenna's shield. I hope it works this time. Confused

vicky · Posted: Sat Dec 30, 2006 12:29 am Post subject:

OK

after an hour out in the wind and rain I cracked it,

had to disconnect the shield totally just using the core wire, soldered the core fly lead into the core of my areil and then routed the screen round just to the radio.

Now all works fine even with power on,

So there seems to be some problem with screen cable on mine,

Anyway its all packed behind the Dashboard now and I am getting instant locks to both 100.1 and 101.1

So happy bunny, have a run down to essex tomorrow so will report on performance

Cheers

coastersteve · Posted: Sat Dec 30, 2006 12:37 am Post subject:

So which did you connect the centre of the coax to? The one nearest the 4 wires or the one furthest away from them?

There could be an inductor between them, I'll look closer when I get to work Tuesday.

Andy_P · Posted: Sat Dec 30, 2006 5:05 am Post subject:

Going back a few posts Darren and Wireplay were talking about the Trafficmaster system. I think I have some info as to why it works so much better than TomTom's efforts.

vicky · Posted: Sat Dec 30, 2006 9:28 am Post subject:

vicky · Posted: Sat Dec 30, 2006 9:34 am Post subject:

------------------
The discontinued Freeway units DID receive pager signals, they were relayed using the nationwide VodaPage network.
------------------

Not quite correct,

Freeway units, (The ones with no screen), just voice instructions, recived the signals direct from the poles at the side of the road, (Limited Range FM Transmitters), you needed to be within about 300m of a pole to get a signal, the service works as a limited range forward facing radar giving warnings approx 30 miles in advance only for direction of travel as calculated by the unit (Based on poles passed), (30quid a year subs) was originally limited to A roads but expanded tot he blue A road poles a few years back (A very good service for the price.)

TrafficMaster Units, The ones with the screens on them, are the ones that use the old analogue pager service, and hence you get a signal almost anywhere and gave details for the whole country at one. (150quid a year subs)

Hope that helps[/quote]

GizmoB73 · Posted: Sat Dec 30, 2006 10:42 am Post subject:

Glad you got it working Vicky, strange about he screen problem. Has anybody else tried this yet? If so how did you get on?

I look forward to hearing how you got on with the coverage on your trip now compared to before.

vicky · Posted: Sat Dec 30, 2006 1:50 pm Post subject:

OK Just completed first trip with the Modded TMC Unit

Sutton In Ashfield Nth Notts to Stamford Lincs and back

Switched on at home, locked to 100.1 and got traffic

Held Service till exiting Mansfield then lost service, nothing futher till on A1 approx 12 miles from Stamford (26 Miles from the Peterborough Transmitter, 40w) Held service to Stamford,

Same on reverse journey.

Bearing in mind the Classic FM Network this is what I expected,

I have just had a run down the M1 from Jnc28 to Jnc26 and got service all the way, (Never had before), again holding the Sutton Coldfield Transmitter

I am hoping now this is modded it should give a fairly uninterupped service up and down the M1 from London to Sheffield. If thats the case then I will be fairly happy with it,

Although I am starting to look at the new LG 9600R in dash unit at the moment at Halfords at 999Pounds, hoping it will drop soon,

just need to find out what TMC service it uses, (anyway thats even futher off topic)

Will give it a good test up and down the M1 next week to see if the Mod is really up to it!.

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