Garmin GMA 350 Installation Manual

Also see for GMA 350: Pilot's guide Pilot's guide Installation manual

Garmin GMA 350 Installation Manual Manual pdf 33 page image

190-01134-11 GMA 350/350c/350H/350Hc Installation ManualRev. J Page 3-53.8 Post Installation CheckoutNOTEThe GMA 350/350H does not provide valid outputs until the aircraft post installationconfiguration procedures are completed.3.8.1 Verify Failsafe Operation with a Mono Headset1. Remove power to the unit by pulling the audio breaker.2. Connect a mono headset to the pilot’s headset output jack and pilot’s mic jack.NOTEUse of a true mono headset is required for this test to insure proper wiring even if a stereojack is provided in the installation. Wiring left channel (tip contact) and right channel(ring contact) backwards will cause failsafe mode not to function with mono headsets. Useof a true mono headset is required for this test (not a stereo headset with a mono/stereoswitch because headset manufactures differ on how they accomplish this switching). Thiswill guarantee the condition of the right channel (ring terminal) being shorted to thereturn (sleeve terminal) by the mono headset’s plug. This short occurs because of thephysical design of the headset plug contacts and is an inevitable consequence of plugginga mono headset into a stereo jack. During power-on operation, this short will not damagethe audio panel.3. Verify that COM1 transceiver can be heard in the pilot’s headset.4. Verify that COM1 can key and transmit the pilot’s mic audio by verifying received sidetone orchecking reception of the transmission with another radio tuned to receive this transmission (verifyPilot PTT and mic operation is delivered to this transceiver).5. Apply unit power by restoring the audio breaker to the normal operating position.3.8.2 Verify Installed Transceivers (COMs) are able to Transmit and Receive1. Connect a headset to the pilot’s headset output and mic input jack.2. Verify each installed transceiver (COM) can be heard when selected.NOTEDepending on settings, the mic selected COM may mute audio from other COMs.3. Verify that each installed transceiver keys for transmission and transmits clear audio from thepilot’s mic when selected for transmission and the Pilot PTT key is pressed.NOTEThe audio panel can be configured to simulate received sidetone internally, verifyingtransmission with a separate radio not in the system is recommended.4. Move the headset to the copilot’s headset jacks and verify that any one of the installedtransceivers (testing each is not necessary) receives and transmits copilot mic properly as above.