Pumpkin AA0461B-A01 in a W169 Mercedes ...

[MarcyBesky]

I got my new digital multimeter on thursday and found out that +12V can be measured at the ANT-cable, when I use the outer silver ring of the cigarette lighter as GND. If I remove the key, the voltage slowly goes down, after around 30 seconds the voltage reaches 0V.

I now tried 2 different phantom adapters with dual FAKRA plugs, one for the FM FAKRA cable and one for the ZF FAKRA cable, the blue 12V cable is connected to the ANT-cable of the PUMPKIN radio, but radio reception is still bad.

I now suspect that maybe the antenna amplifier got moisty and that the antenna doesn't work properly therefore.

I wonder if it's possible to change the outer antenna, which can be screwed off easily against some kind of other none diversity antenna?

Everything is working fine except for radio reception.

[Rigattoni]

To change the rod makes no sense at all.
In this case you need to change the antenna base and pull some new cable through the car. No nice work...

I would try to find someone who is able to test the antenna amplifier. For your car you should be able to find a good used antenna amplifier in Ebay or anything like that.