CB radios have been quietly popular for 30 years. When they first came on the scene, CB radios were liberating. They gave housewives, bored commuters, and students of human nature a new language: CB. "Ten-four" became an abused term. After the wild interest moved on to the Internet chat rooms, CB continued to serve its initial purpose: two-way communication on a budget. Here's how to fix a CB, good buddy.

How Does It Work?

Citizens band radios are miniature receivers and transmittersthat fall under the jurisdiction of the Federal Communications Commission (FCC). Work on the transmitter components should be done only by an FCC radiotelephone-licensed service person.

A citizens band (CB) radio is both a receiver and a transmitter. A radio receiver is an electronic device that receives audio signals through an antenna, then amplifies and sends the sound to speakers. A transmitter does the opposite: it takes microphone (a reverse speaker) signals, converts them into electronic signals, and distributes them via an antenna. CB radios have 40 channels on which you can speak and/or listen. Some, such as channel 9, are set aside for special purposes (emergency assistance), but most are open to whatever you want to talk about. Mobile radios and mobile telephones work approximately the same way.

What Can Go Wrong?

Mobile CB radios, those installed in cars and trucks, run on car battery power. Base stations are corded radio transmitters and receivers. A battery or cord may need replacing. Many CBs have fuses that can be replaced, often from the back of the unit. Contacts can be bent of corroded. Controls and switches may be dirty. Antennas can break or become disconnected.

Because CB radios transmit electronic signals, they come under the jurisdiction of the Federal Communications Commission. You'll need an FCC technician's license to work on a CB or mobile radio, other than a few tasks that can't impact transmission. Cleaning a CB is okay, as is replacing an antenna. And you can replace a Fuse.

How Can I Identify the Problem?

If the CB radio won't work, make sure the car battery is charged, or the electrical cord for a base unit tests okay and replace it if needed.

If the sound is fuzzy, disassemble the unit and locate the volume control. Spray electrical contact cleaner into the control and rotate or slide the control several times to lubricate the mechanism. Replace a damaged or broken antenna (see below).

If the sound is crackly or whines, check the car's noise-suppression filter and ignition coil capacitor (see below).

Fix-It Tip

Don't throw away the owner's manual that comes with your CB radio. It offers information on where to get parts as well as what you can and can't do when attempting to repair your CB. It also includes warranty information.

What Parts, Materials, and Tools Do I Need?

CBs are digital wonders. That means there is little you can do to them without the help of an FCC-licensed technician. Even so, you can clean and maintain your unit. Here are some basic tools for the job:

• Screwdrivers
• Wrenches
• Canned air
• Electronic contact cleaner

What Are the Steps to Fixing It?

Diagnose noise on your CB radio:

1. If the sound is a high-pitched whine that gets higher as the engine speeds up, the cause is probably a defective noise-suppression filter. Buy an exact-replacement unit from an auto parts store and make sure it has installation instructions included.
2. If the sound is a ticking that doesn't get higher pitched but does become more frequent as the engine speeds up, it's probably a defective spark plug wires or a defective ignition coil capacitor. Purchase the replacement parts from an auto parts store that can advise you on installation.

Replace a CB antenna:

1. Loosen the antenna mounting nut on the car fender and remove the antenna. Some CB antennas are temporarily mounted with a magnet base and run a wire between the antenna and the CB radio.
2. Follow the manufacturer's instructions for installing the replacement antenna. (There are entire books on selecting and mounting CB antennas!)

Clean electronic CB components:

1. Unplug the CB radio from power and from the antenna.
2. Remove the screws holding the case together, typically mounted on the bottom of the case.
3. Look for labels and other indications of the transmission circuitry. Don't touch it. You need to be an FCC-licensed technician to work on the transmitter.
4. Use canned air to blow dust from other components including any power cords and speaker jacks.
5. Use electrical contact cleaner or a cotton swab dipped in denatured alcohol to clean electronic components as needed.
6. Reassemble.

Fix-It Tip

Electronic and CB stores typically have books on specific brands and models of CBs including information on what you can do and how to do it.