TomTom TMC - Areas of Service / No Service

plant · Regular Visitor Joined: Nov 26, 2004 Posts: 86

OK, I've been speaking to a local shop holder who deals in new and secondhand electronics - he's a dab hand with a soldering iron etc. I've spoken to him about modifying the aerial and I need to let him know what I need to do (print off here) and let him get on with it.

There are so many different options that people have done on here and bearing in mind it is a company car (no holes or permanent fixtures), what would be the recommended solution.

Appreciate a blow-by-blow suggestion, so it is easy for me to explain. I'm happy with electronics jargon - well I'm not, but I know my friend will be.

Thank you for your suggestions.

Carl.

tonygamble · Regular Visitor Joined: Jan 23, 2007 Posts: 186

My TMC receiver went back to TT today.

It will be interesting to see what comes back.

I will post when it does.

Tony

emjaiuk · Posted: Thu Jan 25, 2007 10:09 pm Post subject:

As new 910 owner, I'd like to express my thanks for the help and ingenuity shown here. Although many have posted helpful comments, Gizmo and Vivky deserve particular praise, and also MikeAlder for his constant and detailed feedback. The only complaint I've got is the fact that Vicky's £9.99 Halford ariel cost me £14.99, although I don't mind since I returned the original £60.00 TMC ariel to Halfords as not fit for purpose, and bought one from Amazon for £45.00.

Thanks again

Malcolm
_________________
Go740L App 9.510 Europe 985.8155
RDS_TMC mount
Home 2.8.3.2499 Win10 Home

plant · Regular Visitor Joined: Nov 26, 2004 Posts: 86

Vicky,

On your mod with the pre-amp taken out of an aerial, can I confirm the following.

Car aerial coax into pre-amp.
single core output to TMC, with coax output to radio.
single core output to TMC is soldered to the pad closest to the 4 wires?
The TMC pad furthest from the 4 wires is not used?
TMC connects to Tom Tom as usual.

If using the correct connectors, can you have the set-up so it is easily removed from one car and installed to another (not expecting a 5 min change, more a 1 hour)?

Many thanks for the clarification or correction (and sorry for being so slow on the understanding!)

Ta.

vicky · Posted: Fri Jan 26, 2007 9:17 am Post subject:

(YES) Car aerial coax into pre-amp.

(YES) single core output to TMC, with coax output to radio.

(NO) single core output to TMC is soldered to the pad closest to the 4 wires? ---- It is the pad furthest away from the 4 wires, (OP of the original instructions realised after taking his pictures that it was the wrong way around)

(NO) The TMC pad furthest from the 4 wires is not used? -- As Above

(YES) TMC connects to Tom Tom as usual.

If using the correct connectors, can you have the set-up so it is easily removed from one car and installed to another (not expecting a 5 min change, more a 1 hour)?

Once set up it can come in and out very quickly, the only thing that makes mine permenent is the fact that I have soldered the +12v wire to the car lead, if you used a plug it should be a 30 second job to remove. Pull out car radio remove TMC from splitter and power replace radio!.

Cheers

foxyloxy · Occasional Visitor Joined: Apr 19, 2004 Posts: 4

Would appreciate some help from those who have experimented.

If I have a single core going to the pad inside RDS/TMC which is furthest away from the four wires then for a conventional car aerial (I suspect mine actually uses the headed rear window element as the aerial as there are no external aerials on the car) should I connect the wire to the core or the braid part (if we assume an old style car aerial plug).

mikealder · Posted: Fri Jan 26, 2007 4:11 pm Post subject:

foxyloxy, I would be very cautious about connecting the TMC unit directly to the aerial feed in your car, most vehicles that use the rear screen heater element as an aerial also use an amplifier to drag out the required performance and make the audio good enough to listen to, I doubt it would be capable of receiving data via TMC though.
You could consider an external aerial dedicated to the job, and if you don't fancy drilling holes in the car look at using a Mag Mount (Maplins do one for under £15 - the Mini-Scan, not quite optimised for the frequency band but close enough). Others have reported simply adding a couple of meters of cable to the pad offers a significant reception boost - Mike

pepperm · Occasional Visitor Joined: May 13, 2006 Posts: 48

The RDS data gets from the aerial to the radio so I would suspect the TMC data will too, if indeed it is not part of the same data stream.

Mark

plant · Regular Visitor Joined: Nov 26, 2004 Posts: 86

Thanks Vicky.

Off to Maplins AM to see what I can use.

Cheers,

emjaiuk · Posted: Fri Jan 26, 2007 11:23 pm Post subject:

Has anybody any thoughts on reducing the length of the original TT TMC cable when used in conjunction with this mod.? I'd like the facility to move my setup between two vehicles on a regular basis together with the occasional hire vehicle. I'm not concerned about amplifying the radios, just the TMC, so what I had in mind was to connect Vicky's amplifier direct to the TT PCB, and mount the lot into one of Maplins neat little plastic boxes together with an aerial socket. I'd then like to run the power and ground wires down with the existing TT power lead, possibly covered in heat shrink tube, to a new cigarette lighter plug, and run them both of a twin socket adapter. If I could shorten the existing TT aerial lead without any degradation in performance it would help tidy up the wires adjacent to the windscreen mount. The two regular vehicles would have fly leads from the existing aerials at the mount postion, and for a hire vehicle I'd use a mag mount aerial.

Any comments gratefully received.

Malcolm
_________________
Go740L App 9.510 Europe 985.8155
RDS_TMC mount
Home 2.8.3.2499 Win10 Home

mikealder · Posted: Sat Jan 27, 2007 9:49 am Post subject:

Malcolm - I would leave the unit alone, for a start the four core flex is not easy to solder (the insulation tends to melt). The TMC unit uses a voltage supplied from the TomTom around 3V IIRC. The actual lead between the TomTom and the head of the RDS-TMC unit is the aerial, so you might make reception worse by shortening it.

When in my own car the TMC is fed directly from an amplified external aerial, when used in hire cars I simply put the TMC unit complete with its three foot of external coax cable (no aerial, as I have found it not necessary, TBH the improvement in performance an aerial offers is only noticeable in very poor reception areas).

If you do shorten the lead make sure you leave plenty of cable to re-terminate the device, the connector that is moulded to the end of the cable is not available to purchase (unless someone knows different) so you need to re-use the existing plug - Mike

emjaiuk · Posted: Sat Jan 27, 2007 11:16 am Post subject:

Thanks for the reply Mike, I think I'll take your advice for now, at least until someone else is brave enough to try it! I'll experiment with bunching up the unwanted cables and see what happens. You never know, seeing as how Tomtom is so responsive to their customers needs they probably bring out a new external aerial connection of their own in the next few days and offer them free of charge to existing TMC owners Smile

_________________
Go740L App 9.510 Europe 985.8155
RDS_TMC mount
Home 2.8.3.2499 Win10 Home

plant · Regular Visitor Joined: Nov 26, 2004 Posts: 86

You been on the mushrooms again Malcolm!

8O

m623d · Regular Visitor Joined: Apr 05, 2005 Posts: 191

OK I just purchased the TMC unit for my 910, after reading the probs on here, but thought I'd give it a go.

Travelled from Grimsby area to London and back yesterday and I only received a signal on the A1 near Peterborough for about 15 miles in both directions!
I was really surprised I got no signal in central London at all.

Will the modifications listed on here really improve this? I dont want to trash my 'expensive' receiver if it wont be LOADS better, I'd rather get a refund until TT sort it out.

I need a removeable system as I use it in a car and a tranny van (not mine, so I cant mess with the aerial/wiring etc)
Cant use a mag mount antenna as the tranny is a high line and I cant reach the roof! not sure they are metal either.
any ideas?

I previously had the Pioneer AVIC-X1R in my car and it always got a signal for TMC, so the issue cant be with the signal strength. It even displayed all information, not just on your route. (even picked up in France and Spain last year, although spain was intermittent)

Also, I read on here that you can manually tune the TMC, but I cant find out how, it just cycles continuously round the freq.
_________________
Garmin Emap, Ipaq 2210 with TomTom Navigator 5, TomTom One, Pioneer AVIC-X1R, TomTom 910 (stolen). TomTom 520, TomTom 6100 (Faulty, replaced under warranty), Currently got a TomTom 6200

pepperm · Occasional Visitor Joined: May 13, 2006 Posts: 48

Unless, like me you like taking things apart and messing with them, I would take it back.

I have driven around with a piece of wire hanging out of my TMC as an aerial for about 3 weeks now and the performance is better than without, but is still poor. So I got the amplified antenna from Halfords and have it rigged up in my "lab" and still the performance is just one notch up from useless. I sometimes get a green signal marker but often not.

The TMC must have the deafest radio receiver ever. I have made crystal sets with better reception.

Mark

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