TomTom RDS-TMC Antenna

[not_so_old_git]

Hi,

I have just bought a TomTom 920T with the 4V00.013 TMC unit and am having variable success with getting a signal.

Does anyone have any suggestions with the positioning of the aerial tail on the car windscreen, for example across the bottom of the screen and up the side or some other permutation!

Also is there any way of linking the TomTom TMC unit into the car radio aerial and has anyone found a right angled adaptor to allow flush connection into the main TomTom Go unit in a similar way to the cigarette lighter power cable?

Any suggestions appreciated.

[AndyVaughan]

There are numerous posts on here regarding this.

Best position is as much of the end of the lead past the plastic bit vertical and at least 2 inch away from any metal bodywork of the car.

Keep the egg as far away from the TT as possible (not easy to do as you only have a 2 inch lead).

Also, try without the charger plugged in - you get a lock in weak signal areas easier.

Plenty of posts on connecting to car aerials - it makes a big difference but make sure that no DC voltage is present on the car aerial wire.

Andy

[Elastic]

[marshall]

hi
i have just travelled about 40 miles from m65 to A56 to Haslingdon then to Rossendale Todmorden. Just before Todmorden I had lock on. this is the first time ever.
As I got closer to Burnley the signal (i presume) got weaker( 75% green Then later 50% green Then 25% green then nil
Does this mean I went from 100% to 25% reception but was still getting traffic updates or did I loose the traffic updates as soon as i lost 100% reception, can someone explain please.

marshall
_________________
marshall TomTom Go 520 , Western Europe v805.1801 map. app 8.2204- v7KATE 4gb sd card + other cards

[mikealder]

That route is a good test of reception due to the terain masking, I have had 100% reception on some trips on the same road, other times it has been patchy.

The green ball when fully illuminated indicates you have had a signal within the last five minutes, but this doesn't always mean you have received data. Each quarter segment in grey denotes 5 minutes without a signal at all, so 50% grey means no signal in the last 10 minutes, 100% grey means no signal in the last 20 minutes, it has nothing directly to do with signal strength - Mike

[smstextaddict]

ive just left mine hanging out of the bottom of the tomtom into the plastic bag it came in, works fine and doesnt get distracting bouncing about on the windscreen or if the sucker fails and it decides to fall onto your lap.

have found if you plug in the tmc bit before you turn it on you get locked on and a better reception than if you are already turned on and then plug in.

[Fozzee]

I bought a 520T last week. I find the traffic receiver works however I place the aerial AS LONG AS THE CHARGER IS NOT PLUGGED IN!!
As soon as I plug the charger back in I lose signal in a few seconds. This renders the TMC useless in my opinion as you can never have the charger and TMC working at the same time.
Also I find my handsfree on 100% volume is extremely crackley WITHOUT the charger cable plugged in but fine WITH it plugged in.
Therefore TMC and a useful working handsfree is not possible either!

Back to the shop tomorrow for a refund...

[mikealder]

Demonstrate the fault at the shop and demand a replacement, the in car charger is most probably at fault - this has been reported on a number of occasions in the forum and as you have found unplugging the charger isn't a good idea when using the unit for hands free, with a decent charger it will work fine unless you have a very noisy (electrically noisy that is) car electrical system - Mike

[Fozzee]

[gardenshed]

doesn't mean that the car electrical system is clean, have you tried a ground filter

[mikealder]

I had a brief MSN session with the site member following this post and for the benefit of others this is a summary of what was detailed:

Try the TomTom connected to the RDS device with the vehicle ignition off - result RDS-TMC works fine.

Try the TomTom connected to the RDS device with the vehicle ignition on but engine off - result RDS-TMC doesn't work.

Try the TomTom connected to the RDS device with the vehicle ignition on but engine running - result RDS-TMC doesn't work.

Whilst it is possible the vehicle could still be inducing noise with the ignition on but engine off it is highly unlikely as a vehicle is DC powered, therefore based upon similar posts previously seen within the forum I would try changing the TomTom vehicle charger lead.

This opens up another can of worms though, the TomTom car chargers are rated to deliver 5V DC at up to 2 amps, most phone chargers are not capable of delivering this level of current. Overloading a charger will induce more electrical noise and potentially lead to failure of the charger which in turn could fry the TomTom (it has happened before). Thus using a Blackberry charger doesn't really prove much in way of interference.

On another note this has got me wondering what the actual current consumption of the TomTom devices is under various operating conditions, I might take some measurements and publish the figures out of interest over the next few weeks (it would take that long to gather the results from the devices and combinations the device can be used with) - Mike

[cjay2412]

i have attached a ferrite bead to my charger lead to stop it interfering with tmc reception which works well. i get signal lock about 95% off the time as apposed to 50% before

[erniesone]

Off topic but can anyone assist?
I am interested in a Tomtom Go - 520/530. I already have an amplified TMC aerial connected to my car aerial - and it works very well.
Do I need to purchase the Traffic version to get RDS traffic info or can I get the standard version and use my own aerial (jack plug looksthe same)

[mikealder]

The TomTom RDS-TMC receiver is far more than just an aerial, it contains electronics to get the data into the correct digital format the device can understand. The plug is actually a six pole affair so it is far from standard, if you want RDS-TMC with either a 520 or 530 you have no option but to purchase the "T" version - Mike

[Tomo]

I know that there have been several threads about the TMC ariel and its positioning including this thread but I would like to add in my experiences.......

Even after reading that you need to lay the lead along the bottom of the screen etc, in view of the sky I thought I would try something.

While fitting a brodit active mount back to the fuse box of my Octavia I also run the TMC lead into the dash, along the top side of the steering column and exited it by the fuse board cover. The last 9 inches or so were exposed but tucked in between the dash and the screen so barely visible.

I used it like this for 2 weeks and had perfect reception, only had an issue where I would of expected (Cumbria M6 where there is no radio signal anyway etc).

So, why whwn so many people have reported problems when its routed "correctly" did I get such good results when it was inside the dash?

Was it to do with the "mouse" bt of it actually sitting on top of the radio head unit and getting some leakage from the arial in?

Steve

We see you’re using an ad-blocker. We’re fine with that and won’t stop you visiting the site.
Have you considered making a donation towards website running costs?.
Or you could disable your ad-blocker for this site. We think you’ll find our adverts are not overbearing!