930 FM xmit-My way to make it actually work-USA

gearloos · Occasional Visitor Joined: Jul 23, 2007 Posts: 12

This might be something already gone over but thought I would share this.
The 930, at least here in the USA, has a crippled fm xmit.
The signal is so weak that I recently took a trip from Los Angeles Ca. to Reno Nv. and NEVER ONCE was I able to tune it and have static free music. The fix I did was 2 things:
1) I took out my cig plug from the dash and put a torroid on the power lead with 4 turns through it.
2) I pulled the antenna from the back of the radio and soldered in a small switch (use a cheap 10 $ antenna to plug in as a pigtail to the switch)to a 6" wire that resides in the dash( Laughing Out Loud

I'm an extra class ham operator and didn't even measure to get an increment of the freq to match it) . When the switch is normal (position 1) radio functions normally. On position 2, the antenna is the 6" wire on the Center conductor only. This deadened the radio enough that I now have clear TomTom mp3 music on almost any station I choose (the big gun stations still get over it).

mikealder · Posted: Sat Jul 05, 2008 9:09 am Post subject:

In order to meet EU regulations the FM Tx output power is very low indeed which does make listening to the music/ instructions via this method somewhat difficult.
It is better to use the Line Out socket to an aux input on the car deck (if it has one) or get a stereo that woks with the TomTom Bluetooth audio output, this is by far the best method, no interference, great audio quality and no wires - Mike

gearloos · Occasional Visitor Joined: Jul 23, 2007 Posts: 12

We have the same problem over here in USA. The FCC set transmit limits to so low a level the devices are truly useless. That is why I call fraud on TomTom (or any other manufacturer that still advertises this as a feature that works). I know it is not TomTom's fault that they can not transmit enough but that does not mitigate the fact that they say it does work. They should say "it works IF you live 100 miles from any metropolitan area AND you have a weak reciever in your car AND you put some type of rf choke on the power cable AFTER the plug going towards the battery (read inside your dash, NOT on the TomTom cable) AND you still don't mind a little static...get my point?
I'm an electrical engineer so to me no big thing but for your average road warrior bussiness person, this is a nightmare.

My radio does not have a aux in and is a Bose factory system that will not accept a new head unit without amplifier/speaker mods.

jimbo_hippo · Frequent Visitor Joined: May 18, 2005 Posts: 444

It does depend on the proximity to the ariel though. In my Motorhome it's very close to the ariel (about 4 feet) and it works ok. In my car the ariel is at the back on the roof and it's poor most of the time.

My biggest gripe is that having the power cable plugged in increases interference to the point where I charge it then unplug it to play back MP3s etc. This has nothing to do with regulations and a lot to do with poor design in my opinion.

Hats off to you for building your own fix but it would be nice for Tom Tom to fix it for us without resorting to a soldering iron or remove the function if it doesn't work as advertised.
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