Page 5-16 400W Series Installation ManualRev. G 190-00356-025.3.12 COM SETUP Page (GNC 420W and GNS 430W Only)Select the COM SETUP Page (see Figure 5-15). Thesevalues are set at the factory and seldom requirecalibration.FREQSelects a VHF communication frequency. For purposesof setting the squelch and sidetone levels, only thefrequencies 118.000, 127.000, and 136.975 MHz can beused.SPACINGSelection Description25.0 kHz Selects traditional 25 kilohertz spacing (760 channel).8.33 kHz Selects 8.33 kilohertz channel spacing, which is required in someareas of the world.CAUTION8.33 kHz channels are not authorized for use in the United States.SQ 250Sets the squelch threshold for 25 kHz channel spacing operation. May be set to any value between 0(zero) and 63. The higher the number, the less signal is required to break squelch.NOTEFor GNC 420W or GNS 430W units with COM software 2.00 or earlier, the operation ofthe SQ 250 setting is reversed. The higher the SQ 250 number, the more signal isrequired to break squelch.SQ 833Sets the squelch threshold for 8.33 kHz channel spacing operation. May be set to any value between 0(zero) and 63. The higher the number, the more signal is required to break squelch.SIDESets the sidetone audio output level. May be set to any value between 0 (zero) and 63.NOTEThe sidetone audio output level is independent of the COM volume knob on the 400WSeries unit.Store Calibration?Select this field and press the ENT key to accept the squelch threshold and sidetone audio settings on thispage. If you wish for the squelch and sidetone settings to return to their previous values, do not select thisfield. Simply change to the next configuration page, or turn off the unit if you are done withconfiguration.Selection Verify That:PTT The box is filled in while the COM push-to-talk switch is pressed.XFR The box is filled in while a remote COM transfer switch is pressed.RX The box is filled in while the COM is receiving a signal.TX The box is filled in while the COM push-to-talk switch is pressed.Figure 5-15. COM SETUP Page
