CB radio is getting engine interference?

[KSDbass]

I installed a CB radio and wired it straight to the battery instead of the cigarette lighter like it came with, and I'm getting what I guess is engine noise. It makes a buzzing noise that increases with engine RPM, so does anyone have any good suggestions for getting rid of the noise?

[Recce]

Check where your antenna cable is running...It wont always be the power cord that causes interference.

[yablanowitz]

That used to be a pretty common problem "back in the day". You used to be able to pick up a line noise filter at Radio Shack that did a good job of cleaning up the noise. If I recall correctly, it was little more than a capacitor to smooth out the wave pattern produced by an alternator. It never used to happen when cars had generators (unless you had leaky plug wires).

[SeanH]

Ditto what yablanowitz said.
To diagnose it further;
If it is alternator noise, the individual beats of the noise will be so close together that it will sound like a whine of varying frequency. In that case the line filter will take care of it.

If it is a leaky ignition system, the individual beats of the sound are discernible, especially at low revs, like a ticking sound. In this case, you need to replace your spark plug wires (if the beats are far apart), or your distributor cap (if you have one and the beats are close together).

BTW, Thanks for dredging up memories from 30 years ago. :)

[J Smith]

Seems like I remember something about the antenna cable length not being right would cause it plus a bunch of other stuff.If you have a CB shop close by they could check it out for you.A lot of times these shops are close to truck stops.

[KSDbass]

I don't think it's the cable, the cable starts in between the driver's seat and the center console, then runs under the seat to the door, and then to the rear bumper. I'll check how defined the noise is when I get home.