2014 Viano 639 Antenna

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MB Enthusiast
Apr 26, 2015
Derbyshire, High Peak
Viano ex long, 651 2014. S211 646 2009 (till the Gov't drones blow 'em off the road)
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.
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.

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