IC-F5020_F6020 series Instruction Manual

1 PANEL DESCRIPTION■ Programmable function keys (continued)Ext. CH Sel Mode KEYPush to turn the Ext. CH Select function ON or OFF.When the function is turned ON, memory channels can beselected with external input operation only.When the function is turned OFF, memory channels can beselected with [CH Up] or [CH Down] operation, or with externalinput operation.• This function is available when the external unit, such as a dimmercontrol is connected to the transceiver with the optional OPC-1939or OPC-2078 cable (p. 16).• Ask your dealer for details of external input operation.6