LØSNING: Oppgradering til DAB-radio i XC70 2008/2009 modeller uten prep.kabel

[SagaPer]

Hi,

Firstly, apologies for writing in English - I am from the UK.

I have been following the thread for your DAB upgrade (using Google Translate) as I am hoping to do something similar myself on my MY13 V40 D2 which was built without the 'DAB Prep' option.

There are 2 antenna inputs on the DABM module as DAB has 2 different frequency bands allocated to it - VHF Band III (174-229Mhz, just above the FM radio band, and so is sometimes called 'DAB FM') and L-Band (1452-1492Mhz, in the middle of the 2 GSM mobile bands). The L-Band frequencies were supposed to be a worldwide standard but apart from a few countries it hasn't been used. In the UK it was used for some test broadcasts, but our DAB transmitter network only operates in the VHF/FM band.

The DABM supports both bands (in the upper right corner of the label on the front panel it shows the 2 frequency bands), which is why it has 2 seperate antenna inputs.

The VHF input comes from the amplifier module connected to the window antenna. On some cars, like the V40, the amplifer module has 2 outputs (FM and DAB) from a common window antenna, as the frequency bands are close enough to be received from the same antenna.


The L-Band input comes from the receiver in the sharks fin. As L-band is much higher frequency it uses a smaller antenna (very similar to a GSM antenna) which is why it's mounted in the sharks fin with the other high-frequency antennae that work best when mounted outside the car.

I don't know about Norway, but as the UK hasn't used the L-Band frequencies for DAB so far (I believe the frequencies have actually been sold off for other uses) the shark fin DAB antenna is effectively redundant here anyway. From what I have read the few countries that did use L-Band for DAB have started migrating services back to VHF Band III instead (although L-Band works OK for cars with an external antenna, the higher frequencies do not propagate as well through buildings for home reception as the VHF band frequencies)

Even if Norway does use L-Band for DAB, I don't think connecting your second VHF-band antenna to to the DABM's L-Band input will do anything, as the antenna is tuned for a much lower frequency band.

On my V40, the upgrade is more complicated as the

MOST

bus needs to be taken from the

AUD

module under the front seat to the DABM in the boot, which would probably require custom fibres to be made. Similarly there is no power or antenna wiring present in the mounting location in the boot. The V40's FM/DAB antenna amplifier is mounted in the tailgate, and a second coax cable and FAKRA connection is fed from the amplifier through the right-hand tailgate loom into the car to connect to the DABM. Unfortunately the version of the tailgate loom in my car does not have this extra connection either, so I would need to add it myself or obtain the complete tailgate loom, along with the required FM/DAB amplifier module.

Hi Buzby, I really appreciate your writeup on this subject. Your information on antennas is really clearyfying. Now everybody with a V70/XC70 2008-2011 knows that the original DAB-antenna in right rear windows is all you need to reeceive DAB-broadcast in Norway (plus exchange of antenna amplifier). In my car there is also a Low-band antenna connected to the Low-band antenna input on the DAB-module. Nice to have. :-)

I recommend to start a thread in the V40 forum describing your project. In English. I think this will be of good value for our forum users. Or start a thread in an English forum and keep us updated along the road.

Fibre optics: I think there is a user called Skripis in this forum who has has a project on connecting fibre optics from sound amplifier beneath front passenger seat to the booth. Send him a PM and ask him what kind of fibre optics he bought on eBay. I think it was some sort of Porche optics which will fit in a Volvo.

Looking forward to follow your project.

PS: I have a sortiment of Fakra plugs for sale: http://forum.vccn.no/showthread.php?...r-DAB-prosjekt.

For norske lesere: Denne informasjonen betyr at det kun er original DAB-antenne i høyre bakrute som er viktig for DAB-mottak i bilen. Haifinnen på taket er originalt satt opp for det såkalte Low-band i DAB og er pt ikke i bruk i Norge. I min beskrivelse av løsning har jeg brukt en kort stavantenne fra Connects2 med ekstern strømforsyning montert øverst i venstre bakrute.