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Re: Alternator whine on RADIO





The problem you're having is that your preamp wire is picking up noise 
from the power cable as both run through the car. So when your signal 
goes into AMP, all the noise that got picked up gets amplified by the 
amp. If you turn off the amp - no problem. You're sending amplified 
signal from the deck and the noise/signal ratio is very small. 

So the solution is to position the preamp cable as far as possible from 
any power wires and to get a really well shielded cable as well. 
Some cables use tin-foil for shielding - that is no good. The wires 
inside the cable have to be coated by a flexible wall of metal.

This is not the problem with you deck, but with your preamp cable.
I think that you may have figured this out yourself, that Radio Shack 
cable maybe the problem.

Hope this helps.

Alex 


> This is what I have:
> 
> The amp. is in the front, tucked in the dash atop the glove box.  
> The amp and the radio share a common ground.
> The amp and the radio get power directly from the battery (10 gauge wire, I
> believe).
> Only the rear speakers are connected to the amp.  Using existing harness. 
> The front ones connect to the radio as before.
> Here's where I think things might be happening.  I'm using a Radio Shack 5
> pin DIN cable to go from the radio preamp out to the amp.  I tried a hand
> made one with same results.  Blaupunkt sells this cable but at CDN$70 I've
> been shying away from it.
> 
> If I remove the amp from the equation, no whine.
> 
> I tried a noise filter, no difference.
> 
> So I've been living with it, hoping the radio dies so that I can justify
> getting a new one.
> 
> If you have any suggestions, I'll give it a shot.
> 
> TIA
> 
> Lino
> 
> 86 5ktqw
>