MIDLAND 4001 - Manual (Page 8)

Midland MODEL 4001 CB Operating controls
FRONT PANEL CONTROLS
ON/OFF VOLUME: In the off position your transceiver power is off. Turn
this control clockwise to switch on the unit and adjust the volume.
SQUELCH CONTROL: Adjust this control until background noise just
disappears. If the control is adjusted too far clockwise it may cause
muting of weaker signals.
RF GAIN CONTROL: Adjust this control counter-clockwise to reduce
reception of interfering signals.
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