Garmin GMA 340 Installation Manual

Also see for GMA 340: Pilot's guide Supplemental operation manual Pilot's guide Pilot's guide Pilot's guide

GMA 340 Installation Manual Page 3-3190-00149-01 Rev. L3.1.5 Split Com (Not Applicable to Dual ADF)Pressing the COM 1/2 button (15) activates the split com function. While this mode is active, COM 2 isdedicated solely to the copilot as a MIC/audio source while COM 1 is dedicated to the pilot as a MIC/audiosource. The pilot can still listen to COM 3, NAV 1, NAV 2, DME, ADF, and MKR. The pilot and copilot cansimultaneously transmit in this mode, the pilot transmitting over COM 1 and the copilot transmitting over COM 2.The SPLIT COM mode is cancelled by pressing the COM 1/2 button a second time.While in the split com mode the copilot may make PA announcements while the pilot continues using COM 1independently. When the PA button is pressed after the split com mode is activated, the copilot’s mic is outputover the cabin speaker when keyed. A second press of the PA button returns the copilot to normal split comoperation.NOTEIf the com radios in the installation utilize a “transmit interlock” system, the splitcom function may require that this feature is enabled. Refer to the radio’sinstallation manual for guidance. Garmin makes no expressed or impliedguarantees regarding the suitability of the split com feature in a giveninstallation.3.1.6 Com Swap FunctionThe GMA 340 allows the use of a remote mounted switch (typically on the yoke) to alternately transfer the activemicrophone back and forth between COM 1 and COM 2. The remote switch should be a momentary type,connected between J2 pin 20 (SWAP*) and J2 pin 21 (SWAP return). Pressing the remote switch will have noaffect if COM 3 is the active transceiver or when split com is in use.3.1.7 Aircraft Radios & NavigationNOTEAudio level is controlled by the selected nav radio volume control.Pressing NAV 1, NAV 2, DME, ADF (16), or MKR (2) (see MKR beacon operation) selects that audio source. Asecond button press deselects the audio source.In addition, the GMA 340 provides inputs for an unswitched aircraft radio (TEL RINGER) and an unmuted,unswitched aircraft radio (ALT WRN).3.1.8 Speaker OutputPressing the SPKR button (12) selects Aircraft radios over the cabin speaker. The speaker output is muted when aCOM microphone is keyed. Speaker level is adjustable through an access hole in the top of the unit (see figure 2-3).