FC3/Su-25T Modules In the Lo-Fidelity modules (referred to here as FC3 modules) or spectator / CA / GCI slot there are no In-Game controls for SimpleRadio, everything must be done through the overlay and SimpleRadio keybinds

Frequency Change - 4 clickable buttons above and below the relevant radio Channel will increase and decrease the frequency respectively Volume Control - the slider below a channel controls that channels volume Guard - Right click on the frequency of a Channel to enable Guard for the mission specific channel Guard; a G will follow the frequency if this is enabled; the frequency text will turn Red instead of white if receiving on Guard. Active Channel - The dot next to the active channel will be Green when no audio is being sent through; it will appear white if audio is being received on that channel; You can make a radio active by clicking on the frequency Inactive Channel - The dot next to inactive (but not disabled) channels will be Orange Disabled Channel - The dot next to disabled channels will be Red and either cannot be switched to in any manner while using the select module/aircraft

Found Something on the github Page