CB radio alternator whine

[JHZR2]

Hi,

In my MB turbodiesel I had mounted a CB radio on the side of the consile in the passenger's footwell, so that I could put up an antenna and have CB radio for long trips. Worked like a charm.

My replacement car is a new saab 9-3... a GREAT car, but a gas engine... couple that to the fact that at least until warranty is up Im not attaching anything directly to the battery, and I have a good setup for alternator whine in my CB radio.

Is there any sort of thing that I can attach between a cigarette lighter and the radio to help reduce the whine that I hear, especially when driving in traffic with lots of auxiliaries on? It gets quite annoying.

I have seen these little units at crutchfield that claim to be:

quote:

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Problem: You plug your portable music player into the aux input on your car's receiver, but there's an annoying whine along with the music.

Solution: PAC's SNI-1/3.5 preamp noise filter plugs in between your receiver's auxiliary input and your portable music player to help reduce noise caused by a ground loop. The filter includes a female 3.5mm input, a male 3.5mm output, and 10 inches of cable for each jack.

---

I was thinking that if all else fails, I would buy an external CB speaker, and use this piece in between the CB and the speaker to try and reduce noise... but there is no guarantee and I dont know if itd work.

Plus Im hoping for a better solution... if one exists. Any suggestion?

Thanks!

JMH

 

[Al]

I had lots of cb radios and never had a hum. I had a mum in another radio and the things that were advertised to correct it didn/t

 

[brianl703]

http://www.autosound2000.com/filters.html

Also, you can get an add-a-circuit fuseholder at Pep Boys/Autozone/etc. that will allow you to connect the CB radio directly to your fusepanel.

 

[Master ACiD]

i had a porsche with a subwoofer back in the day. the sub was directly connected to the battery via a power wire i personally ran and i insured the power wire and the ground were very securely connected and of the appropriate thickness. whenever the engine was on i would get this wineing sound that went up in frequency as the engine revved higher. i determined it was the alternator because when i disconnected the alternators belt, the wine stopped.

granted that i cant run the car for very long with no alternator, i resolved to just live with the noise untill i got rid of the car, for other reasons mind you.

 

[ShortBuSX]

Ground noise.

 

[Gary Allan]

You need a capacitor attached to the alternator lug to ground. It's a block to DC ..but will shunt any frequency (your whine) to ground. It was a common practice in "the old days" ..and was done on blower motors too.

 

[ALS]

The best way to fix the problem is connect the power line directly to the battery. Also make sure you have a good ground connection. I would get a quick disconnect instead of the cigarette lighter unit. That way you can hard wire the unit in and still pull it out or put it in quickly.

 

[kanling]

It might be noise coming in from the electrical power. You need a "choke". Like one of those round cylindrical doodads on power cords for computers. You can buy snap on ones, probably available at radio shack. I'm sure radio shack carries noise eliminators for CBs, which will be essentially the same thing, maybe a bit fancier.

 

[rpn453]

Try an inline alternator noise filter, like that N-25 model on brianl's link.