The External Keypad feature for the IC-7610 is documented on p. 13-4 of the IC-7610 Basic User Manual. The keypad is connected to the rear-panel [EXT KEYPAD] jack via a 3.5mm TRS (tip-ring-sleeve) plug, as shown in the schematic below and on p. 13-4 of the Basic manual.
To enable the external keypad and MUTE function, turn
ON the following menu item:
MENU » SET > Connectors > External Keypad
The mute switch is connected between Ring and Sleeve of the TRS plug, as shown. The mute switch inhibits transmit and receive functions. The rest of the keypad circuitry is needed only if full keypad functionality is desired.
Last updated: 03/10/2019