Garmin GPS 400W,GNC 420W Pilot's Manual & Reference

Also see for 400W Series: Supplemental Flight manual Pilot's guide addendum Manual supplement Pilot's guide addendum Quick reference guide

Contents

Garmin GPS 400W,GNC 420W Pilot's Manual & Reference Manual pdf 33 page image

231 - COMRadio Volume / Auto SquelchSection 1Communicating Using theGNC 420W/AW and GNS 430W/AWSome models of the 400W-series feature a digitally-tuned VHF COM radio that provides a seamless transi-tion from communication to navigation. The GNC420W and GNS 430W’s COM radio operates in theaviation voice band, from 118.000 to 136.975 MHz,in 25 kHz steps (default). For European operations, aCOM radio configuration of 8.33 kHz steps is pro-vided (Section 9 - Aux - Setup 2). The GNC 420AWand GNS 430AW use a 16-watt transmitter, instead ofthe standard 10-watt transmitter.“TX” appears at the upper right corner ofthe screen while transmitting.VolumeCOM radio volume is adjusted using the COMpower/volume knob. Turn the COM power/volumeknob clockwise to increase volume, or counterclock-wise to decrease volume.SquelchThe COM radio features an automatic squelch toreject many localized noise sources. You may overridethe squelch function by pressing the COM power/volume knob. This facilitates listening to a distant sta-tion or setting the desired volume level.Press the COM power/volume knob momen-tarily to override the automatic squelch.Note the “RX” receive indication whenreceiving a station.To override the automatic squelch, press the COMpower/volume knob momentarily. Press the COMpower/volume knob again to return to automaticsquelch operation.420W / 430W Only