Tomtom TMC antenna -- horizontal or vertical?

PicklesDad · Occasional Visitor Joined: Jan 06, 2008 Posts: 35

Greenglide thanks for the tips.

My splitter has just arrived. I ordered this one:

http://www.cartft.com/catalog/il/671

as it looked like it used a thicker cable, but what I got looks exactly like this one:

http://www.cartft.com/catalog/il/539

without the extra adapter. Sad

Now to find the time to fit it!

Retty · Frequent Visitor Joined: Sep 07, 2006 Posts: 336

Greenglide · Posted: Fri Jan 18, 2008 2:42 pm Post subject:

It took me a while to work out the difference, especially with the mention of Sirf3.

The 3.5mm plug is an odd one - it is a 4 pole - barrel, two rings and tip - not a standard stereo which the 2.5mm one is.

I intend cutting the jack plug off anyway one it is properly installed and using a 3.5mm mono connector.

I am assuming that the cable is a standard coax. The barrel is connected to the coax screen through the splitter (as I would expect) neither of the other two connections has a DC connection to anything - it obviously blocks DC from aerial amplifiers (the Zafira doesnt use the aerial lead to power its amplifier anyway) but whether one or both are connected to the plug I can't tell. Using a 2.5mm in line mono jack has got round this for the moment.

Don't know what I'll do if there turns out to be 3 wires (don't see how).

Retty · Frequent Visitor Joined: Sep 07, 2006 Posts: 336

The cable is standard coax.

The 2.5 mm plug is connected to the 3.5 mm plug by way of a standard coax extension cable which is wired to the first pin on the 4 pole 3.5 mm jack plug. The Cartft product (Navilock branded) is based, I am told, on the GNS chipset design which allows for multiple devices (headphone, TMC aerial and perhaps others) to be connected to the same socket. The 4 pole 3.5 mm plug is needed for the devices equipped with the relevant 3.5 mm input in order to ensure that the sat nav unit does not detect the incorrect device.

With Mio (C710), Medion and certain Navigon devices the TMC aerial needs to be connected to the first pin on the 4 pole 3.5 mm device. You will have problems if it isn't although you may still have some success on the basis of signal leakage across the pins. Assuming that is that the unit doesn't "think" that you're connecting a headphone set (in which case sound will be cut off).

In short the 3.5 mm 4 pole connector is necessary because of the multi function nature of the input device - accepting both headphones and TMC input. How would the unit distinguish between the 2 other than through different pin connections?

The Cartft device is made by Navilock and is basically, at least as far as I can see, modelled on the GNS devices which perform the same functions.

I've asked GNS (in poor German) if a coax cable wired to the first pin of a 4 pole 3.5 mm plug should work with their 3.5 mm input boards. They told me - although I'm not completely sure that I or they understood the question - that the cable needs to be soldered to the first pin.

I wouldn't hack this cable if I were you. Surely far better to sell it on eBay for the purchase price plus postage (you would probably get it) and then buy the one you need.

It is very difficult, even with good soldering skills, to hack the required cable. I tried to repair the shoe string aerial that came with my C710 by approaching a (good) electrician with 35 years experience - the solder looked good but there's clearly interference because the aerial works only intermittently and occasionally blocks out sound.

I had a professional installation of my TMC adaptor. The guy in the shop - very experienced - said that he would only agree to solder a new cable (if the plug and play installation didn't work) on the basis that I was prepared to take the risk of failure. He explained that it is a very tricky job.

Luckily I didn't need the service - the device worked out of the box.

I wouldn't invalidate the warranty by hacking the provided cable. Sell it if you can and go for the one you want.

carl_w · Lifetime Member Joined: Mar 13, 2004 Posts: 242

PicklesDad · Occasional Visitor Joined: Jan 06, 2008 Posts: 35

Well I had a go at installing it today. Everything went fine until I removed the rear screw to release the metal stereo enclosure. It was cloudy today and I hadn't noticed the the metal box wasn't actually a box, but had big holes in the bottom. The tip of my screwdriver dropped off and fell down the gap to disappear into the darkness, at least I've still got the screw. I knew it was a loose fit, but thought it would just get caught by the enclosure. Embarassed

On removing the enclosure and the cables attached to it I found my next problem. The car aerial plug doesn't connect into the rear of the enclosure. It actually fits into a hole in the enclosure forming the plug that goes into the stereo, and the plug has special tags to hold it in place in the enclosure. The aerial splitter doesn't have those, so wont stay in place.

Anyway, I thought I would at least test things. I attached the splitter to the aerial and attached the leads directly to the radio outside of the dashboard. I had already cut off the aerial from the TMC lead and stripped the remaining end back to produce a bare wire for both the core and shield. I then held both onto the jack from the splitter. The shield went to the jack connection closest to its base, and the core to the connection at the end of the tip.

The TomTom started to search for a frequency. Straight away I knew it was better as the gaps between its choice of search frequencies was much smaller, usually it is all over the place. I had previously tried it on my house aerial where I first noticed this. Next thing I know I have a car and arrow then a green dot. Obviously I couldn't drive anywhere with no hands free Very Happy

but I did repeat the search a few times and it locked on with no problems.

Since I was already having problems with my manufacturer's stereo (RDS won't lock on and now it won't always turn on without a few tries), plus I would like bluetooth and a USB port, I have decided the best route is to find a third party stereo with the right aerial connector on the enclosure. I just have to find the right model and adapter to keep my dashboard display and steering wheel controls.

if1977 · Posted: Fri Jan 18, 2008 10:49 pm Post subject:

Sorry for butting in here and if i am reading this wrong but you can get an ariel adaptor which will connect one type to the other. At the rear of the stereo where the ariel goes some stick out where the ariel clips on and some are inside where the ariel goes into it like a tunnel. Obviously one wont fit the other but this inch long adaptor is a couple of quid from any autoparts shop and connects the 2 different ariel sockets together.

The other thing you talk about is the metal box, this is actually the (CAGE) for the stereo to stop thiefs from stealing the stereo and has a 20torx screw at the back (the one you took out) to remove the cage. You can get a smaller cage also which is just as safe but clips into the front half of the stereo nad leaves the rear halp exposed and you can put the cables directly into the unit without having to put them in the rear of the CAGE first. These are a couple of pounds to and are universal size also.

I have done this installation loads of times and know exactly what you are talking about. I hope you can understand what i am saying and this helps you with your repair.
_________________
NEW Tomtom GO 500 (hope it is good)
iphone (running all day, doesn't like it)
XL LIVE IQ Routes (Got stolen and miss it)
GO 510 (in drawer now, time for upgrade)

PicklesDad · Occasional Visitor Joined: Jan 06, 2008 Posts: 35

I always welcome help, but shush don't let my wife hear I'm trying to get a new car stereo Wink

if1977 · Posted: Fri Jan 18, 2008 11:29 pm Post subject:

Even without the cage the antenna will securely fit to the stereo, the way it clips to the cage first is really a guide for slipping the radio in.
_________________
NEW Tomtom GO 500 (hope it is good)
iphone (running all day, doesn't like it)
XL LIVE IQ Routes (Got stolen and miss it)
GO 510 (in drawer now, time for upgrade)

PicklesDad · Occasional Visitor Joined: Jan 06, 2008 Posts: 35

Thanks for the idea, but I tried that and the ribs and right angle on the connector of the aerial splitter stop it from going all the way. They touch the cage, and even if it has made an electrical connection it feels like it could still easily drop off. I don't really want to try cutting a bigger hole in the cage to stop it.

I could buy two aerial connectors and cut the existing car aerial and insert the splitter in between, but I think if I'm going to spend any sort of effort on it I'd rather spend it on putting a new stereo in. After about the 10th time of trying to turn it on it's lucky it is in a theft prevention cage as it would have been out the window otherwise. Laughing

if1977 · Posted: Sat Jan 19, 2008 12:01 am Post subject:

What you say about the right angle of the connector not going all the way in is correct but the adaptor i was talking about goes in between them and fits perfectly and secure. If you decide to carry on i could exchange some details with you and talk you through it and you do not even need to cut a single thing and can be done in a few hours. Anyway good luck and hope you talk the wife into a new stereo. Laughing

_________________
NEW Tomtom GO 500 (hope it is good)
iphone (running all day, doesn't like it)
XL LIVE IQ Routes (Got stolen and miss it)
GO 510 (in drawer now, time for upgrade)

ticex · Posted: Sat Jan 19, 2008 7:16 am Post subject:

I'm trying to do a similar thing but luckily my car (VW Golf Mk5) has 2 antenna feeds installed. I've also bought a FAKRA antenna socket suitable for the car. I have the latest tomtom tmc dongle with the long trailing wire after the bubble receiver unit so I'm wondering it it's a simple case of chopping the end of this wire and soldering it onto the antenna socket then connecting it to the spare antenna feed? I'm a complete novice at this but I guess there will be a central wire needing connected to the centre of the socket and an outer one which should be connected to the outer one on the socket...is this correct?

One issue I'm wondering, I sometimes use the tmc dongle in other cars but will it still work in the "normal" way when I disconnect it from my cars antenna with the end chopped off ?

Thanks in advance for any help! Cool

Greenglide · Posted: Mon Jan 21, 2008 3:44 pm Post subject:

ticex All you need to do is fit an in-line socket (or plug depending on what is connected to the TMC receiver) to the "piece of string" cut off. This enables you reconstruct the original cable.

PicklesDad Hmm - I had forgotten about the aerial connector mounting in the cage - this also makes the splitter difficult to connect to it - now I know why!

I didn't have this issue as I already had an aftermarket head unit fitted.

Mine is a Pioneer P65BT and is a great radio / CD player and a very average BT handsfree (doesnt read the address book from the phone very well etc - the TT 520 is much better).

The adaptor for the sterring wheel controls works fine. If you have the separate display with the large dots in the display this continues to work and shows the data and time with no radio connected so you dont need to get a more expensive connector that drives that as well (I did and all it does is display the RDS data you can see on the front of the radio!

PicklesDad · Occasional Visitor Joined: Jan 06, 2008 Posts: 35

if1977: Last weekend I visited a local fitter to see what he had, though he couldn't help and recommended I cut the hole bigger. It doesn't matter now as I've ordered an after market stereo, but thanks for the offer of help.

ticex: That's generally right, but it's actually one inner set of twisted wires acting as a single core surrounded by insulation and then an outer braid which shields the inner core from interference. I'd recommend searching the Internet for guides on how to prepare coax cable as it is not as simple as joining two wires. I'm fortunate enough to have done an electronics apprenticeship 22 years ago, and it's practice that you need, so try to find an off-cut of coax cable to practice on first. You will at least need, cutters, wire strippers, small pliers, a knife and soldering equipment.

Greenglide: I ordered the Sony MEX-BT5100 yesterday from:

http://www.incarexpress.co.uk/view_product.php?partno=MEXBT5100

I liked the Pioneer, but the Sony display connector was £56 vs nearly £90 for the Pioneer one.

http://www.incarexpress.co.uk/view_product.php?partno=DOPS004

I can see why you think the display is not worth it at that additional cost. I hadn't seen your post before I ordered the display version, although I did read the Sony would display ID3 tags. Guess I'll just have to wait and see.

All: Last weekend I got my splitter installed, albeit with the existing radio not inserted all the way back in (Whilst I wait for an after-market radio).
My initial tests in my village showed it to lock on and go green when I turned it on, but if a told it to search for a station again it would only get to the car and arrow. If I turned the device on and off again it would go green. This was repeatable and nothing changed in between - the car and device were stationary. Very strange. The Classic FM signal on the radio did have some distortion, but got no better when the splitter was removed, so it must have always been there.

I tested it today (Monday) along the A14 between Bury St Edmunds and Ipswich. I consistently got a green dot apart from a small drop out for a few seconds down a dip before the Orwell bridge. I then found it had re-tuned to a different Classic FM station. In fact I purposely told it to search for a station a few times just to check it was finding it and not just showing green from the last time. So very early tests indicate it was probably worth doing. Only time will tell, and of course I await to see the accuracy of the information. It did locate flooding on a route near the wash, which I purposely entered after looking for problems using Teletext.

I have a longer version of a Bee String aerial on the Zafira, but does any know of any high gain compatible whip aerials that might improve the signal further? I don't want to change the base, just use the existing 5mm socket.

I've taken lots of pics so will try and write it up sometime.

Thanks!

Greenglide · Posted: Tue Jan 22, 2008 1:27 pm Post subject:

The Sony head unit looks fine and experience has shown that Sony understand BlueTooth better than Pioneer.

Looks better than the Pioneer. Shame it wasn't on the market when I bought mine Sad

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