The Automatic Noise Limiter button on your CB radio reduces the amount of noise and audio interference coming from your automobile's engine and transmitted through your CB's speaker. The feature also filters out noise coming from power lines, atmospheric sound waves, cellular phones, heavy equipment and machines in the area you are using your CB radio. The ANL feature only reduces background noise and doesn't totally eliminate it.
Once you activate the ANL feature by flipping the ANL button to the "On," Active" or similarly worded position, the ANL feature immediately starts reducing background noise and starts sending clear messages from other CB radio users to your radio. You will notice less static and breakup in messages and less noise from your automobile's engine. Some CB radio ANL buttons require you to push the button in to activate the feature. The push-in buttons work the same as the flip buttons in reducing interference and noise.
On some CB radio models, the ANL button is known as the Noise Blanker button, but it works the same as the ANL button. The button or switch is clearly labeled "Noise Blanker," "NB" or "ANL/NB." Whenever you are using your CB radio, activate the ANL, NB, ANL/NB or Noise Blanker feature to hear messages clearly.
If you don't physically see an ANL, NB, ANL/NB or Noise Blanker button or switch, consult your CB radio's owner's manual to see if the Automatic Noise Limiter feature is built into your radio and is always active. Some CB radio models contain the feature but do not let you disable it via a button or switch. If this is the case for your radio, the manual will clearly state that a noise reduction or limiter component is present.
Adding the ANL Feature
Not all CB radios contain an ANL button or feature. If you don't see an ANL button or the feature is not built into your CB radio, you cannot add the button or feature. Attempting to or modifying your CB radio to add the ANL feature can damage the radio and void its warranty, if still active. Purchase a CB radio that contains an ANL button or feature if you live in an area where background noise is a problem or your automobile is emitting engine noise that is interfering with your CB radio.
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