  CARRIER SQUELCH

  This feature will adjust the carrier squelch value that the radio uses
  when the mode select switch is in the carrier squelch position. Carrier
  Squelch values range from 0, for Open Squelch, to 15, for Tight Squelch.
  Values may be entered directly with the Numeric Keys, or scrolled through
  with the Up/Down Arrow Keys.  NOTE: The mode select switch should be in
  the Carrier Squelch position when adjusting the Carrier Squelch.
