Uniden BC244CLT User Manual page 15

4. Set the SQUELCH control to AUTO for the factory setting. Or, manually set squelch
as follows:
Think of squelch as a gate. Turn SQUELCH fully counter clockwise. This
raises the "Squelch Gate" so high that only very strong signals can
get through.
Turn SQUELCH fully clockwise until you hear a hiss. This lowers the
"Squelch Gate" so that everything gets through — noise, weak signals, and
strong signals.
Turn SQUELCH back counter clockwise until the hiss stops. Now the
"Squelch Gate" allows only strong signals through.
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