Navman F20 + T1 TMC reception problems cured

oolaa · Occasional Visitor Joined: Apr 05, 2006 Posts: 8

Just thought I'd share the solution I put together from information gathered from around these forums & others.

This solution has worked well for me but you follow these instructions at your own risk of injury or damage. This involves soldering & ideally you need to buy / borrow an inexpensive multimeter to test connections.

I decided that I
a) Didn't want another external antenna,
b) Didn't want to damaged any components that would harm my resale value / reuse of expensive components bought.

I achieved this in 3 steps on my 2004 Ford Mondeo

1) Purchased TMC-Y-adapter cable ISO from Navigon website (£35.00 inc postage) https://www.navigon.com/site/int/en/shop/consumer/accessories/26
Please note your car may have a different connector to the ISO one so check first.

This is fitted behind the radio & the end for the traffic emerges via the glove box. This connector is a 2.5mm jack plug which needs adapting to fit the T1

2) Purchased a short MCX to MCX cable from ebay for a few pounds to canibalise. These are also available from cpc.co.uk but more expensive. If you really don't want want your Navman supplied wet string T-Bar antenna you could chop that off. Leave yourself about 6 inches of cable from the plug.

3) Purchase a 2.5mm In line stereo socket (Maplin part FT93B ) cost 89 pence on the highstreet to save postage. I bought 2 as my soldering skills are not great & I knew I'd mess one up!

4) Strip a few cm of cable back leaving the centre core in it's in plastic insulation. The outer braiding will need connecting too but make sure the inner core & braiding don't touch each other.

The inner cable needs soldering to the terminal on the Line socket that will connect with the tip of the jack plug.

The outer braiding needs soldering or crimping to the outer section / cable relief on the line socket.

The second terminal remains unconnected.

This is where a multimeter will come in handy to check you have made the right connections & have no shorting.

5) Finally connect everything together & your TMC signal quality improve dramatically!

Mine went from approx 40% (basically only when in major cities) to 95% (almost seamless service)

Dustysworld · Posted: Sat May 26, 2007 6:09 am Post subject:

So to get a unit that should work out of the box you spent about £40 plus to achieve this Confused

I went for the external route and was cheesed of spending £25 to achieve my aims. Personally i think thats way to much money to spend on something that should work out of the box, let alone £40 ish
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www.dustysworld.net

oolaa · Occasional Visitor Joined: Apr 05, 2006 Posts: 8

Mine did work out of the box , just not everywhere.

I'm not saying it's right but I think manufacturers are covered by putting on the packaging "*Subject to coverage".

They should at least warn that you may need an external antenna (& make one available!) in the same way as they do for the GPS signal.

I was annoyed with myself for not doing the research before purchasing.
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Navman 510

mikealder · Posted: Sat May 26, 2007 4:11 pm Post subject:

Nice set of detailed instructions for getting better reception, iTIS the service provider even recommend coupling to an external aerial for the best results, see This post for further details -
It is the manufacturer 's that let the side down offering poorly thought out aerials and receivers, at least Navman offer the connection point, have a little sympathy for TomTom RDS-TMC users who have to open the device and solder to the PCB with limited results, and whilst doing this they void the waranty - Mike

keithjeffrey · Posted: Sat May 26, 2007 5:47 pm Post subject:

I went the Maplin mag-mount external aerial plus Garmin adaptor route , which cost me about £ 35.00.

Believe me , I was'nt happy having to pay it , but I was'nt going to get my T1 to do what it SHOULD do without forking out.

Navman don't think / won't admit there is a problem , so the only thing to do is to put your hand in your pocket yet again.

Not the ideal solution , but a solution none the less !
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Keith
TomTom GO 730T App 8.392 (1909/091109) , W and CE 2GB v835.2419

2216 · Regular Visitor Joined: Dec 10, 2005 Posts: 245

This is the way that I used to get better signal on my Sony U50T even down to the 2.5mm jack. It's worth the effort as it's now locking on 95% of the time.

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