What Does the Delta Tune Knob on a CB Radio Do?

By Nick Davis

Your CB radio's delta tune is one of many audio adjusts present on the radio.
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Your Citizens Band radio includes an array of controls for receiving, adjusting and listening to audio from other CB radio users. The radio's delta tune knob, also known as the clarifier control, reduces the amount of static present on the radio when communicating with another person. When turned one way or another, the knob reduces the pitch of the person's voice and makes the voice clearer and less squeaky.

Location and SSB

The delta tune knob is present on the front of your CB radio and works similar to the volume knob. Turn the knob to the left or right until you receive the desired clarity level. The delta tune component only works while in the single-sideband mode and eliminates drifts in frequencies. Drifts happen within the SSB mode, resulting in you hearing another CB user's voice as well as static transmitting through your radio.


The delta tune component changes the actual frequency of the CB radio station you are receiving -- enabling you to go 2.5 kilohertz below or above the frequency of the station. When adjusting the delta tune knob, turn the knob slowly until the radio's audio is clear -- usually to the center position. If you change stations, you will also have to adjust the delta tune knob again until the audio on the new station becomes clear.


If you don't use your CB radio's delta tune component, audio from another CB user will be partially obscured by static; the user's voice may also sound muffled, extremely high pitched or extremely deep, as if he is in a tunnel or far away. Finally, you may notice interference from a CB station above or below the station you are currently tuned to and using.

Missing Component

Not all CB radios contain a delta tune component. If you don't notice a delta tune knob on the front of your CB radio, look for a slider or knob on the bottom or sides of your radio with the heading "Delta Tune" or "Clarifier." If you still don't see the component, consult your owner's manual for references to "delta tune" or "clarifier." The component may be a feature that is automatically adjusted when you tune to a CB radio station, without the option for manual adjustment.