2-10 Garmin GTN 725/750 Pilot’s Guide 190-01007-03 Rev. BForewordGettingStartedAudio &Xpdr CtrlCom/NavFPLDirect-ToProcChartsWpt InfoMapTrafficTerrainWeatherNearestMusicUtilitiesSystemMessagesSymbolsAppendixIndex2.2.4 Cabin Speaker Selection and VolumeThe Cabin Speaker key turns the cabin speaker on and off. The SpeakerVolume key sets the volume level.1. Touch the Cabin Speaker key to toggle the cabin speakeron and off.2. Touch the Speaker Volume key to set the Cabin Speakervolume. Touch the Speaker Volume arrows to set thevolume.Touch ToIncrease VolumeTouch ToDecrease VolumePercent Of Maximum Volume Graphic Scale Showing VolumeFigure 2-13 Cabin Speaker Volume Selection2.2.5 Marker Audio and VolumeThe optional Marker Beacon Receiver uses an audio indicator to alert youwhen the aircraft passes over a Marker Beacon transmitter. The audio from theMarker Beacon Receiver can be heard unless disabled by selecting Marker Audio.When Marker is selected (green bar shown), the tones for Marker Beacons areheard. When Marker is not selected (green bar not shown), the tones for MarkerBeacons are not heard.The GMA 35 marker beacon receiver and indicators are part of the ILS system.The marker beacon lamps operate independently of any audio selection andcannot be turned off. The GMA 35 can drive external marker lamps if requiredand also provides an autopilot middle marker sense output.Prior to beginning an ILS approach, select high or low marker sensitivity withthe Marker Hi Sense key. The lighted green bar in the key illuminates for highsensitivity and remains off for low sensitivity.Touching the Marker Audio key prior to an approach allows the markeraudio tones to be heard in the headsets. When the green bar in the MarkerAudio key shows, the marker audio will be heard when available. The AudioPanel key will change to a Mute key. Touching the Mute key while audio isheard will mute the marker audio until the next beacon is received. The markerbeacon signal sensitivity threshold can be set in Configuration mode. Contact aGarmin-authorized service center for adjustment.
