How often do you get to take a club plane and land on something other than the usual 5,000 ft paved runway? Myself and so did 5 other planes enjoying the desert heat at L90 practicing soft field takeoffs and landings, power off 180s, and other emergencies

The word squelch means to suppress. In your audio panel, the squelch circuit is meant to suppress the sensitivity or gain of the headset microphones.