1998 Mk 3 (8 valve) radio noise

[Darth Vader]

Newbie here but was wondering if anyone can help please because this is driving me carzy.

I've connected a Pioneer CD but get a horrible noise with LW/AM. FM is also very poor (I can only pick up 3 ststaions). I've read some threads here about adding a signal amplifier, which has been done, but the problem remains.

I get a lot of whine over the radio when reving the engine, and when I turn on the fan in the car!

Really not sure what is going on here or what to check. Suspect some sort of earth loop/grounding but how do I go about checking?

I've just dowloaded the install doctor document for removing a radio/replacing with new for the Jetta - is this compatible with the Golf mk 3?

If anyone can give me a walk-through on things to check would be really grateful. Also, is it possible I need a suppressor because of the engine whine?

Thanks in advance.

[Darth Vader]

As an update - sorted out aerial in that I now get fantastic FM reception, and pick up several stations, but LW and MW are poor. I do pick up 2 stations at the far end of MW but everything else is gone. Been advised (by Halfords) that attempting to fit a suppressor etc. to clean up MW/LW is futile as the aerial itself is acting as an earth?

[Darth Vader]

And maybe a final query...

Anyone know where I can get an original head unit for the Mk 3 Gti??