X7 - reusing the RNEG aerial base for DAB+?

[Darko]

I'm in the process of replacing the RNEG on a 2009 C5 X7 saloon with an aftermarket unit with a DAB+ receiver.

If at all possible, I'd like to avoid replacing the main aerial base (looks like a difficult job to do without damaging the roof liner) and those windscreen DAB antennas also produce mixed results.

Since my RNEG has dual tuner, if I understand correctly, it has 3 coaxial connections:
- amplified FM
- unamplified FM
- GPS

So I'd reuse the amplified FM and GPS connections directly for the new HU. That still leaves the third one.

The factory fitted aerial is not suitable for DAB, but I was thinking of replacing it with a one from a car with DAB:

So my question is - since the aerial looks like just a wire, would replacing it and keeping the same aerial base still allow me to use the unused FM connector for DAB?

[Darko]

OK so the more I look at this, the more confused I'm getting.

In the parts schematic, there's only one amplifier pictured, but there's actually two part numbers for RNEG, so apparently both FM1 and FM2 are amplified:

So that probably means that the roof aerial only has one coax for GPS and that's it. Pictures of the aerial base 6561RH only seem to shown one wire coming out of it.

I'm unable to find those amplifiers on any of the wiring diagrams.

So my options are either:
1. change the aerial base with a DAB one
2. replace one of the amplifiers with a DAB one from another car (Ford looks similar)
3. replace one of the amplifiers with a ching-chong DAB aerial, but solder the aerial lead to the window one
4. replace one of the amplifiers with a ching-chong DAB glass stick-on aerial and just reuse the coax cable

With the first option, I think it would be the easiest to run an extension coax from the base to one of the amplifiers, disconnecting it and just reusing the connector there to avoid having to run the coax across the whole care. It's the most "invasive" option.

For the second option, connectors would be different, but also not a lot of connections either (aerial, +12 and FAKRA out). Reception (due to antenna design) would not be optimal, but could still work ...

Am I thinking in the right direction?

[GiveMeABreak]

How the aerials are used can depend on the vehicle - on some the FM2 aerial is not used....

Pop your VIN up so I can see what you have. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

(Note if you are attaching images in future, please use the full post editor and upload directly to the Forum as those last images cannot be magnified and advertise an image hosting service. I have uploaded them directly now).

[Darko]

Thanks! I'll upload the images directly in the future.

The VIN is: VF7**************[VIN obfuscated, can be read by forum staff]

[GiveMeABreak]

Remember that DAB works on different frequencies. A 'wound' FM aerial should be ok, but I suspect it may be trial and error as to the quality.

Unfortunately, Citroen omitted the specific information concerning the MyWay (RNEG) on the C5 X7, so there isn't the detail I was hoping for. For Peugeot 5008, both aerials are 'active', but one is not used.

I think you are going to have to try it and see to be honest.

[Darko]

Almost two years later, I finally got around to it.

I bought a rear window aerial amplifier from Ford, similar to the one I linked in the first post; model JX7T-18C847-BD (AM/FM/DAB+)

I couldn't find any documentation about the connection for either the original Citroen or the Ford one. From all the photos I could find, I saw that first two pins on the Ford amplifier were connected to the aerial and pins 2 and 3 were bridged together.

On the C5 one, all 3 pins on the amplifier were connected to the window aerial. After looking at where the cables go, I concluded that the first two pins are two FM aerials, connected at the top of the window, while the third pin, connected to the thick strip aerial, was the AM one.

I suppose the Ford ones might not even use the AM aerials and that's why the third pin is not connected anywhere separately. I did the same since the new radio does not have an AM receiver at all.

Unfortunately the 3-pin connector, while very similar, did not fit into the new amplifier, but the pin sizes were the same, so I just disassembled the connector and plugged in each of the pins separately.

Since the amplifier has active electronics inside, I assumed it is powered by phantom power via the Fakra connector. I used a generic power injector on the radio/navigation side, connected to the antenna power wire supplied by the radio.

For FM radio, I just used the other amplifier remaining in the car, also with the addition of the Fakra power injector.

Much to my surprise and joy, upon powering on for the first time, I had perfect reception on both FM and DAB+ frequencies!

I'm really happy how it worked out, much better reception than those DAB+ aerial window stickers and certainly much easier than taking off the headliner to replace the roof aerial!