Hi! I couldn`t find an answer to this question, so I post a new topic.

 

FM is soon shut down in Norway, so I need to replace the original Blaupunkt Nexus head unit in my Skoda Octavia (Estate 2007, 1,9TDi, 4x4).

I`ve looked at Android head units, like This one. I`ve heard bad things about the self adhesive antennas that attach to the inside of the windscreen, so I want to use a roof antenna. First I thought of using the original, but it seem to be of the active type, and then the amp probably need to be bypassed. So I found one with P/N 6R0035501D that I notice several people here have used. It has DAB, FM, GPS and GSM (I think..). Since the original antenna has two cables I thought these maybe could be reused, to avoid having to remove the headliner to pull new cables. But when I removed the Blaupunkt head unit, the cable with the white FAKRA connector is marked 75 Ohms? I assume that this is the FM connector. The other one has a blue FAKRA connector. Probably GPS? I can`t find any markings on this cable. It`s thinner than the other. 

 

I assume that the 6R0035501D antenna short cables are all 50 Ohms? Not sure how critical this is, but it would be nice to just get some conversion cables, and use the original cables. I only need FM and DAB, and maybe power for the antenna. I don`t know if the Pumpkin head unit have phantom power for the antenna, or if the 6R0035501D antenna use phantom power, or a separate wire?

I used this part with my DAB installation on my pre FL Octavia. I don't know the answer about impedance but I have no issues and all I needed to do was run a black FAKRA cable for DAB and reuse the wires already there for GSM (dark red), GPS (blue) and AM / FM (white). In my case with it being a pre FL like yours, I needed to convert the plugs at the aerial end to FAKRA with some adaptor plugs. I didn't touch the diversity aerial connections (in my case coming from the rear quarterlight).

 

If you haven't already got a GPS or GSM wire it is pretty much the same task but just using more cables. I didn't drop the whole headlining (only by passenger A pillar) but instead fed the wires down the side of the headlining using a tube from the back. I just needed to take care not to damage the airbag in the A pillar when pulling the new DAB wire out at the other end.

 

The DAB Columbus head unit delivers phantom power to the aerial, I think via the AM/FM wire. Obviously you will need to check your Android HU does the same.

 

Adam

Edited 13 April, 20179 yr by adamal

Impedance matching is important to maximise signal power transfer, but 75 & 50 ohm are not significantly different in practice, both are 'low impedance'.  You only need to worry about mixing low and high (hundreds to 1000's of ohms difference). 

On 13.4.2017 at 08:36, skodacarman said:

Impedance matching is important to maximise signal power transfer, but 75 & 50 ohm are not significantly different in practice, both are 'low impedance'.  You only need to worry about mixing low and high (hundreds to 1000's of ohms difference). 

Yes, probably insignificant. VSWR should be 1,5:1, or return loss about 14dB, so less than 1/20 of the signal is wasted.

 

On 13.4.2017 at 04:15, adamal said:

I used this part with my DAB installation on my pre FL Octavia. I don't know the answer about impedance but I have no issues and all I needed to do was run a black FAKRA cable for DAB and reuse the wires already there for GSM (dark red), GPS (blue) and AM / FM (white). In my case with it being a pre FL like yours, I needed to convert the plugs at the aerial end to FAKRA with some adaptor plugs. I didn't touch the diversity aerial connections (in my case coming from the rear quarterlight).

 

If you haven't already got a GPS or GSM wire it is pretty much the same task but just using more cables. I didn't drop the whole headlining (only by passenger A pillar) but instead fed the wires down the side of the headlining using a tube from the back. I just needed to take care not to damage the airbag in the A pillar when pulling the new DAB wire out at the other end.

 

The DAB Columbus head unit delivers phantom power to the aerial, I think via the AM/FM wire. Obviously you will need to check your Android HU does the same.

 

Adam

Thanks! Did you have to make any holes to get the cables behind the glove compartment? I have not seen anyone route the cables under the floor mat? Would this be more work? Did you route a cable for a back-up camera? Did you route the DAB-cable with the connector in place? So far I have not been able to find out if the HU delivers phantom power.

No holes - there are plenty there already (to side of HU cage) and then once glove box is out, it is easy to cable tie the leads to existing looms. I did remove the outer shroud of the fakra connectors for easier access. 

 

I did read a post where someone had cable tied the bt mic. lead to the curtain airbag - obviously not recommended!!

 

I could have run rvc wiring at the same time but I went for an updated rvc display instead so went under the lower door trim for that as the rvc module which needed changing is above nearside rear wheel arch...

 

Adam

Edited 14 April, 20179 yr by adamal

18 hours ago, adamal said:

No holes - there are plenty there already (to side of HU cage) and then once glove box is out, it is easy to cable tie the leads to existing looms. I did remove the outer shroud of the fakra connectors for easier access. 

 

I did read a post where someone had cable tied the bt mic. lead to the curtain airbag - obviously not recommended!!

 

I could have run rvc wiring at the same time but I went for an updated rvc display instead so went under the lower door trim for that as the rvc module which needed changing is above nearside rear wheel arch...

 

Adam

Thanks! Have not decided yet if I`m going to run any cables. The two originals should be usable for DAB and FM, but I need a cable for the rvc. Have found the needed conversion cables for the antenna end. Seems that the original cables are located at the left side (driver side) in my car. But it seems better to use the passenger side. Any risk involved removing the trim off the A-pillar? Still couldn`t find out if the HU provides phantom power. I think I have to order and find out myself. Also, I found at least two possible partnumbers for the existing antenna, 1UO 035 507 A and 1JO 035 507 A. Don`t know which I have, will probably have to remove the trim and have a look. Would be nice to have the correct conversion cables when the new antenna arrives..Some have FM and GPS, and some have also GSM. 

The DAB Columbus runs 12v dc to the DAB antenna through the DAB aerial connection.

There is no risk in removing the A pillar trim if you are careful with the airbag (if present). It clips off easily altough if there is an airbag you need to remove one screw (under the airbag logo).

 

Rustynuts will be correct about the phantom power being in the DAB line - he is much more knowledgable than me.

 

Try co-star.co.uk for adaptors. I can't quite remember what I needed - it was smb male to fakra female off the top of my head, but I suggest you look first. It is dead easy to pull down the lining at the back of the roof.

 

Cheers

Adam

Edited 15 April, 20179 yr by adamal

Hi! I`ve received the android head unit, and it works well so far. Are currently using the enclosed DAB (self adhesive) antenna, just placed flat on the dash. Have removed the A-pillar and rear trim. Have confirmed the connector types on the original antenna: FME and RAKU2 male. Have ordered a  Kinetic DRA6003 antenna from dabonwheels.co.uk, and adapters from eBay. The android head unit delivers phantom power on the FM connector. Will use the original antenna cables, but will also run at least one new for the rear camera. The rear camera doesn`t fit into the licence plate light hole, so I`m yet not sure where to put it.. Maybe try on the inside of the rear window.