DAB Roof Antenna Replacement?

[kampernaut]

My first post so please treat me gently. I've just bought a 2004 3dr Polo Twist for my son so I think I'm posting on the correct board?

The car has an aftermarket radio fitted and I wish to replace it with a DAB unit. Rather than use a glass mount aerial, I would like to replace the bee sting antenna with a proper DAB aerial both for cosmetic reasons and because I know this is necessary for adequate reception in my area. I have some questions I hope you can help answer.

1. I realise that replacing the antenna involves dropping the headlining and whilst I've found various written descriptions of this I can't find any pictures. Can anyone point me in the right place please?

2. I presume that some sort of plastic tool is required to pry off various pieces of trim without damaging them. Can anyone recommend something?

3. I imagine that I must route a new cable to connect the new antenna to the head unit. Is that correct? If so, how do you go about doing that?

4. The existing aftermarket head unit seems to have been fitted rather poorly. There is no AM reception (dodgy antenna?) and the head unit does not remember its settings when the ignition is switched off. I haven't looked at the plugs on the back yet but what plugs were fitted to the original wiring harness and what is the best way fitting adaptors so that it is easy to fit modern head units?

5. Are there any speakers behind the rear speaker grilles?

Many thanks in advance for all your help.

K

[kampernaut]

4. The existing aftermarket head unit seems to have been fitted rather poorly. There is no AM reception (dodgy antenna?) and the head unit does not remember its settings when the ignition is switched off. I haven't looked at the plugs on the back yet but what plugs were fitted to the original wiring harness and what is the best way fitting adaptors so that it is easy to fit modern head units?

So I've managed to answer this one myself. The connectors on the wiring harness are standard ISO 10487 so no adaptors needed except for an active DIN antenna adaptor (e.g. this one) that is required for most after market head units. The functionality of this adaptor was built into the original equipment stereos. My car didn't have one of these adaptors and that probably explains the poor radio reception. I also found that whoever installed the radio had not connected the switched and permanent power supplies to the right inputs on the head unit which is why it wasn't retaining the settings.

[chewy_]

I've been thinking about fitting a DAB unit in mine.

Did you have to feed new wire though to the aerial or did you use the existing wire with adapters? What aerial did you use?

[chewy_]

Doesn't matter I've just noticed you can get glass mount antennas so that saves the job or replacing my current aerial

[kampernaut]

Doesn't matter I've just noticed you can get glass mount antennas so that saves the job or replacing my current aerial

They didn't work for me on my other VW (a 40+ year old camper) and I was forced to use a proper bee-sting. I regularly travel through a very mountainous area where FM is terrible but DAB works provided you have a good enough aerial. This company provides ratings on all the aerials they sell and you can see the screen/glass mount ones aren't rated very highly (I'm not recommending that company by the way, I've never used them. I just thought the rating was interesting).

Problem with DAB is it either works perfectly or doesn't at all. Its on or off. Its not like analogue where you can experience a tolerable degradation in audio quality as the reception degrades. Reception on your aerial must be above a particular threshold for the places you travel. So the screen/glass mount aerials might be fine for you but equally they might not. You only really know if you try them.

The screen/glass mount aerials also look like a bodge IMO.

Routing the cables was easy and obvious in my camper. Not obvious to me in the Polo.