241 - COMCom Window and TuningCOM Window and TuningCommunication frequencies are selected with thetuning cursor in the standby COM frequency field,and using the small and large left knobs to dial inthe desired frequency. The standby frequency alwaysappears below the active frequency. The active fre-quency is the frequency currently in use for transmitand receive operations.Tuning cursor in the COM window. Use thesmall and large left knobs to dial in thedesired standby frequency.A frequency may also be quickly selected from thedatabase by simply highlighting the desired frequencyon any of the main pages and pressing the ENT key.This process is referred to as auto-tuning. Once afrequency is selected in the standby field, it may betransferred to the active frequency by pressing theCOM flip-flop key.Once the standby frequency is selected, usethe COM flip-flop key to make the frequencyactive for transmit and receive operations.While receiving a station, an “RX” indicationappears in the upper right corner of the COM window— to the immediate right of “COM”. A “TX” indicationappears at this location while you are transmitting.NOTE: The tuning cursor will normally appearin the COM window, unless placed in the VLOCwindow by pressing the small left knob. Whenthe tuning cursor is in the VLOC window, it willautomatically return to the COM window after 30seconds of inactivity. This does not apply to theGNS 420W.The active frequency in either window cannot beaccessed directly—only the standby frequency will behighlighted by the tuning cursor.To select a COM frequency:1. If the tuning cursor is not currently in the COMwindow, press the small left knob momen-tarily.2. Turn the large left knob to select the desiredmegahertz (MHz) value. For example, the“118” portion of the frequency “118.300”.3. Turn the small left knob to select the desiredkilohertz (kHz) value. For example, the “.300”portion of the frequency “118.300”.To make the standby frequency the active fre-quency, press the COM flip-flop key.The tuning cursor will remain in the COM window.The GNS 430W/AW unit has a built-in VOR/Localizer/Glideslope capability. If you wish to select a VOR/localizer/ILS frequency, press the small left knobmomentarily to place the cursor in the VLOC window.Additional instructions for VOR/localizer/ILS opera-tions are available in Sections 5 and 8.420W / 430W Only
