Your CB radio will either perform poorly or not work at all if you have a problem with its voltage regulator. CB radios use voltage regulators to control how much power runs through the device at a given point. Voltage regulators deliver a constant power flow within the operational range of the device. AM regulators, a type of voltage regulator, control how much power enters the CB radio's transmission and reception components. The Federal Communications Commission permits CB radio usage over 40 AM channels.
Not Enough Juice to Run
If an AM CB's voltage regulator is malfunctioning, it may cut off the power supply at too low a voltage. The CB will not work unless it has sufficient voltage to operate properly. If the power supply voltage is low, the radio may operate at a weak level, which affects reception, transmission and speaker volume. In extreme cases, the CB will be unable to power on if the voltage regulator isn't allowing enough electricity through.
Transmitter Static Susceptibility
When a CB AM voltage regulator malfunctions, the person on the other end of the conversation may hear a substantial amount of static coming from your transmission. Both AM and FM transmissions are susceptible to slight changes in transmission amplitude, but transmission amplitude variance only affects sound quality for AM radios. Switching AM voltage regulators can improve energy efficiency in the outgoing signal. Voltage regulators are replaceable parts; swapping in a new part fixes the problem.
Receiver Noise and Distortion
A CB radio with a failing AM voltage regulator may experience a substantial amount of noise and distortion coming from the speakers. A malfunctioning AM regulator may push the radio's hardware into a nonoptimal voltage somewhere starting at the current feed to the antenna along the way to the speaker. If the current is too high or too low, the signal may pick up static, lose information and distort along the way creating a less-than-desirable audio output.
Blown Fuses and Damaged Hardware
CB radios can use voltage regulators to step down voltage from a power source to prevent damage to the device. Additionally, battery-powered CBs can improve power efficiency and operate longer on a single charge with voltage regulator help. However, a malfunctioning voltage regulator that allows too much electricity through will damage the device. Depending on the CB, the device may have a fuse designed to break and prevent damage to the rest of the device if the current is too strong. The current will break the CB if there's no fuse in the device or the fuse fails to blow.
- PBS.org A Science Odyssey: Radio Transmission
- Google Patents: Amplitude Modulated Switching Voltage Regulator
- Google Patents: Amplitude Modulation Circuit
- Dimension Engineering: Dimension Engineering's BEC FAQ
- PC Magazine Encyclopedia: Definition of: Voltage Regulator
- GME: TX311 Super Compact 5 Watt 80 Channel UHF Radio
- Galaxy: DX 94HP Owner's Manual
- Radio Shack Support Tutorials: CB (Citizen's Band) Radio Answers
- Photo Credit Hemera Technologies/PhotoObjects.net/Getty Images