CB Noise

[RSCaptain]

I have a Cobra 19 DX IV wired directly to the battery and a Little Wil magnet mount antenna on the rear trunklid. I notice if the ignition is off and I turn the radio on, I get a steady drone sound. If I turn the car on, the drone now is slightly higher pitched and slightly louder. The drone does not change much when I'm driving around. It does not go up and down with the throttle. When someone's voice comes through the drone is eliminated. I am trying to figure out what the source of the noise is and what I have to do to eliminate it completely. What should I check? I looked where I wired the red and black wires to the battery and they look OK. I simply bent the wire into a hook shape and tightened the bolt around it so it is secured. Someone said to check the antenna cable - but I don't know how this could be a problem because I ran it under the steering wheel and down the drivers side between the plastic molding that makes the floorboards and the carpet. It then goes under the back seat into the trunk. Ahhh

Do I need to purchase a filter/cleaner, and which one should I get?

[The Breeze]

Do you have your squelch adjusted properly? Dumb question I know, but that's a good start. I looked at your radio and it does not have a NB/ANL switch so a filter might help in your case. Sparky has a couple to choose from, and I would guess the lowest priced one will do what you need. Personally, if it is not to annoying, I would live with it as is. That's just me though.

[RSCaptain]

Do you have your squelch adjusted properly? Dumb question I know, but that's a good start. I looked at your radio and it does not have a NB/ANL switch so a filter might help in your case. Sparky has a couple to choose from, and I would guess the lowest priced one will do what you need. Personally, if it is not to annoying, I would live with it as is. That's just me though.

I have tried adjusting the squelch but it does not help much. If I turn the squelch up past one quarter I cut out all noise completely (including noise from people talking). I'm thinking it is either related to the power wires, the antenna wire, or maybe the mic? My radio is supposed to have the ANL (it is permanently on).

How do I determine where the interference is coming from?

It's just too annoying to live with...

[The Breeze]

How do I determine where the interference is coming from?

It's just too annoying to live with...

Don't know for sure, it’s hard to tell. Post your question on sparky's message board, or the, ask the tech thread. Maybe we could both learn something.

[languy99]

It's noise that is induced in the power lines, I fixed that on my car with a Diesel Electronics dc noise filter, it installs in series with the ground and power wires going to the cb. Something like this works http://www.premiere-electronics.net/...owercords.html

[RSCaptain]

Thanks for the suggestions. I will look into getting one of those filters that goes between the battery and the radio.

Is it the case that the closer the filter is to the radio the better?

Also, before I purchase this, is there any way to rule out any other possibilities for sure?

I will be driving across NY state on Tuesday and making the return next weekend, I will definitely post my experiences when I'm back. I'm hoping I can go to a local CB store tomorrow, buy the part, and fix it so that I won't have to listen to that whining for several hours, lol. Thanks guys.

[languy99]

yeah unhook the antenna form the back of the cb (but don't hit the transmit button, you will kill the radio). Is the noise still there, if so than it is coming down the power wires and the filter will help. If the noise is gone, it's coming down the antenna. Noise coming down the antenna is a harder fix, its usually a ground but it can be done.

[RSCaptain]

yeah unhook the antenna form the back of the cb (but don't hit the transmit button, you will kill the radio). Is the noise still there, if so than it is coming down the power wires and the filter will help. If the noise is gone, it's coming down the antenna. Noise coming down the antenna is a harder fix, its usually a ground but it can be done.

I did this test and when the radio is on and the antenna unplugged there is no noise. So if it's usually a ground issue I'm confused, because it is a magnet mount antenna - how can I correct the grounding?

[languy99]

by what you are describing in your original post and what you have tole me there is nothing you can do about that, it is natural. Some higher end CB radios have the RF gain that you can mess with and even a speaker select switch so you can emphasize the low end of the noise and tune out the high pitched noise. Remember that this is AM band and it is noisy, it's not digital and you pickup all kinds of electrical signals. sorry

[languy99]

a ground issue in an antenna means there is a ton of static and the SWR would be really high. It is not a ground issue from what you are telling me.