dab aerial replacement

[AMCross]

hi guys
my dab system comes up with no signal

now i know part of the rear screen has two aerials

one has three wires going from aerial amplifier

and the other has two wires

is there an aerial you can buy so i can plug in and make sure the head unit etc work and its the rear screen thats at fault

steeler wanted £110 to look at it

[AMCross]

no one had similar issue ?

[BMTouring]

DAB has more than one frequency. DAB+ is a little different. FM has diversity (more than one antenna to pick the best from), DAB does not (need it).



DAB is merely an digital stream carried over the FM frequency. Both DAB frequencies can be in the sharkfin. I've seen an older one with only DAB and in the wiring diagrams I see a sharkfin with both DAB and DAB+ (or DABL and DABIII)



I offer an after market DAB+ unit that integrates into i-Drive (currently for E70, not yet for F series) and I have found that from three types of antenna these are the results in my area where DAB+ reception is rather poor:

stick-on straight antenna (vertically to the inside of the rear cargo area side window) reception is acceptable. On a rear window (sedan) it works fine. on a front window the engine is too close so reception is poor with the engine running.

stick-on curved antenna (to save space, the optimal length of the wire is longer in a straight line than the size of the window). Not as good as the straight one (even with the ends hanging over the sills)



External antenna: magnet foot, not practical in carwash/unfriendly hands, but reception is great. It's a bit like the early days of GSM carkits with an external antenna. About the same size and looks. Did not find a glue-on (outside) with a coutnerpart on the inside of the glass for a comparable price though. They to exist in the UK, seen some webshops offering them.


I have not seen any sharkfins with a pointy antenna sticking out for BMW, they exist for VAG cars but the mounting is totally different.



note: this is for DAB+ in Europe, I have no knowledge of the US technology in this (Sirius?) and it's hardware related to that.



Cost of these antennas: 8-20 EUR from china and up to many-fold for the same thing nearby.



There is little technology in them: more expensive offers nothing more in reception, only in durability maybe (for the external one). Note the connectors though: the sharkfin has FAKRA (which is SMB with an outside) and find FAKRA-Z which fits on all other FAKRA variants. Most offers are with SMB plugs so you may need a small cable to adapt from one to the other.

[BMTouring]

forgot to mention: OEM DAB antenna is in the sharkfin, not the windows.