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Discussion Starter · #1 ·
Have noticed recently, electrical interference on weaker FM stations from the ACC (fan). Turn it off, and, hey presto, interference gone! Any ideas ? The radio sits in the first slot under the ACC. Have wondered about moving it to one of the lower ones.
 

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As the fan is not in the ACC unit itself moving the radio one slot would not make any difference.

Have you checked that the aerial cable is fully inserted and is firmly seated? If you unplug the aerial and leave the radio on is the noise still there? (i.e. is it coming in via the aerial or is it coming in down the power connectors)

Steve
 

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Also, is it really the fan, does the pitch vary with fan speed? could it be the little interior temp fan making the iterference?

As Stephen said, check that the aerial cable is home (and not routed past a noisy component).

My aerial lead in the Aero is appalinly short and broken, but I get no noise luckily.

Andrew

Got my spelling's terrible!
 

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Discussion Starter · #4 ·
Thanks to both of you. The problem comes and goes with the ACC. If I turn it off, then the interference stops, likewise, it is only there when the fan is running. The coax lead has been extended by a previous owner (probably because it was also too short), it was just joined, but I have put a new plug on, but noise still there. Will check tomorrow re your ideas.
 

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Seeing as I fiddle about with radios for a living, there are a few things here I can add that you may want to think about.

Just to rule out the obvious, you say you've replaced the connectors to extend the cables. I assume that the connectors were fitted with the braid to the outer of the connector?

The second (and this is what everyone else has mentioned) is the coax shield around the antenna cable. A few of things could have happened here. First, the cable could have rubbed away a section of the shield, and the second is the shield has broken away from the connector either at the radio end or the antenna end. This would be my guess as the most likely problem.

The third is that electric motors can have a largish capacitor (aka condensor) across the terminals to supress any noise generated by the motor. If this capacitor has broken down, and is no longer working as it should this would allow noise out down the wiring and into the radio. However this is speculation, and I suspect a pain to get at. Therefore I'd hold off on this until 100% certain that this is where the problem lies.

Re StephenA's suggestion that you disconnect the antenna for fault finding, I'd add one thing. To be meaningful you will need to terminate the antenna in some way. By this I mean shorting the inner of the connector on the radio to the outer with a bit of wire. This will NOT hurt your radio. Short circuits typically aren't good, but radios are designed to cope with them on their antennas, and this will stop anything leaking in throught the antenna. If you can hear the noise with the antenna connector disconnected and the short in place then any noise must be leaking in through the supplies or speakers or antenna motor wire, or some such.

Hope this helps....

John P
 

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Discussion Starter · #6 ·
Thanks for that John - very comprehensive. A previous owner has extended the aerial lead. I have intended to get out today and take the carpet up around the tunnel, because that is where the join is, but haven't had chance yet. Looks like tomorrow now. It maybe sounds a little sad, but the weaker station I want to listen to is Radio 2 which is fine with engine/acc off. My local radio station and Radio 1 etc is fine. Just Radio 2 when the ACC is running. But I will check that join out tomorrow now.
 

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Well the solution is simple... Don't listen to Radio 2

Cheers
John

To whom, thanks to an engineering education, the glass is neither half full of half empty, just twice as big as it needs to be.....
 
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