2014 Viano 639 Antenna

[m80]

On the later version of the 639 the front screen antenna is connected to the amplifier by 2 push on connectors.
There are then 2 coax leads down to the head unit, with 2 Fakra type plugs into the head.

Is anyone able to tell me why 2 leads?
Are they both serving the same purpose?

The FM reception is poor and unreliable. Even when I unplug my additional kit.
I've fitted ferrite tubes here and there, no appreciable difference.

I'm now considering a roof mounted antenna,
this will be more remote from any electrical interference.
It would only have 1 FM coax.

I'm anticipating fitting a dual antenna that can provide for FM and DAB+.
It would have its own amplifier.

Any thoughts are welcome.

 

[m80]

For others who may have the same questions.

Of the 2 Fakra HU outputs, The black Fakra provides the FM input to the HU. The white Fakra is a 12 volt output from the HU to power the amp.

So the ground field is provided by the chassis, as is normal on early models.

I fitted a DAB+ USB dongle to the Android HU. In the more advanced world there are many stations available, and hold a better signal than my unreliable FM. Up here in the outback both are less than reliable. The DAB signal so far is from a screen stuck on antenna. I have a roof mounted, amplified antenna coming. That, if worth while from testing, will provide the DAB+ and FM. The screen original MB antenna and amp would then be redundant.