Garmin GMA 240 Pilot's Guide - Page 7

GMA 240 Audio Panel Mono/Stereo Headsets The unit can accommodate up to four (4) headsets (Pilot, Copilot and up to two (2) passengers). The use of stereo headsets is highly recommended. If monaural headsets are plugged into stereo jacks, power supply fuses may be damaged. When wired correctly, the use of a monaural headset in a stereo jack shorts the right headset channel to ground. Anyone listening on a monaural headset hears only the left channel in both ears. If a monaural headset is used at one of the passenger positions, anyone else listening on a stereo headset hears audio in the left ear only, unless their headset has a mono/ stereo switch set to mono. Power ON/OFF The GMA 240 may be powered ON and OFF with the avionics master switch. The unit may also be turned ON and OFF with the Pilot ICS Volume Knob. Rotate the knob clockwise out of the detent to turn ON. Rotate the knob counterclockwise into the detent to turn OFF. During power-up, the unit undergoes a self-test, illuminating all panel annunciator lights for about two (2) seconds. Once the self-test is complete, the unit is ready for use with the same keys selected as when the system was last powered OFF. Transceivers Pressing COM1 MIC or COM2 MIC Key selects the transmitter and receiver audio for the selected transceiver source. The active COM audio is always heard on the Pilot headphones. Audio level is controlled by the selected COM radio volume control. Either audio source can be selected independently by pressing the COM1 or COM2 receiver keys. When selected this way, they remain active as audio sources regardless of which transceiver has been selected for microphone use. 190-00917-00 Rev. A Garmin GMA 240 Pilot's Guide 7