Audio 20 Pinout Diagram

Page may contain affiliate links. Please see terms for details.

E55BOF

Hardcore MB Enthusiast
SUPPORTER
Joined
Mar 11, 2013
Messages
10,768
Location
South Bucks
Car
CLS63 SB, SLK55, CLK350 'Vert, Triumph Sprint (Bike not Dolly...),
The car is a 2008 CLK (W209) Convertible. I have removed the head unit - basic poverty spec Audio 20, single CD, no MOST, no CD changer, no Nav, steering wheel volume control, and that's it. The only surprise was two Fakra aerial connectors, not one; turns out the 'vert has two radio aerials as standard, one front one rear, and of course, no roof aerial.

Does anybody have a pinout diagram for the Audio 20 so I can work out what goes where on the (NOS) Blaupunkt Stockholm 370 DAB BT single DIN head unit I'm fitting?
 
Audio 20 model no. MF2740, if that helps?
 
STOP PRESS: Found what I wanted. :D
 
I have no political ambitions. Come and get me, Darling...
 
Last edited:
Thank you; I will.

What is the mustard one actually for, though? And is the mustard one the front or the rear aerial connector? (I ask because I'm curious, not because I'm going to ignore your advice).
 
Thank you; I will.

What is the mustard one actually for, though? And is the mustard one the front or the rear aerial connector? (I ask because I'm curious, not because I'm going to ignore your advice).
Your original head unit processes the signals from more than one antenna ("Diversity"), which is why you have 2 Fakra connectors.
 
Thank you for that. I assume, then, that two signal inputs down one aerial feed would interfere with each other, despite the fact that it was one and the same signal when it was transmitted? A layman (me) would have thought (and I did) that having two signal inputs would simply give a stronger signal.
 
Last edited:
A diversity aerial sytem is used to help improve reception when in areas of poor reception, such as among city centre tower blocks or in hilly areas. The radio can receive reflected instances of the same signal, causing interference. The radio uses signals from more than one aerial to minimise this interference by combining the signals and electronically choosing the best bits in real time.
 
Thank you for that. I assume, then, that two signal inputs down one aerial feed would interfere with each other, despite the fact that it was one and the same signal when it was transmitted?
As Stratman says, the clever bit happens at the head unit, which doesn't just receive the signals from the aerials, it actually processes them.. As the aftermarket unit doesn't do this, yes you're right, feeding two sets of antenna signals into it won't necessarily give you 2 times better reception.
 
As the aftermarket unit doesn't do this, yes you're right, feeding two sets of antenna signals into it won't necessarily give you 2 times better reception.
In fact, it could indeed generate interference if there are reflected signals around. Thank you, gentlemen.
 
Yes, I have the DAB aerial to fit.
 
Have to be windscreen; no roof aerial on a convertible. At least it will be easier than dropping the roof lining.
 

Users who are viewing this thread

Back
Top Bottom