[Elecraft] K3S Line in not working.

[Richard Ferch]

A potential explanation: the LINE IN level may have defaulted to zero.

The LINE IN level is adjusted using the MIC gain control, but only when MIC
SEL is set to LINE. So, you need to set MIC SEL to LINE (which turns
MIC+LIN off), adjust the MIC gain control to give the desired non-zero LINE
IN level reading, then if you really want to use MIC+LIN on, set MIC SEL
back to your chosen mic setting and set MIC+LIN to ON.

For FT8, it would make more sense to set MIC+LIN to OFF and MIC SEL to
LINE. The MIC SEL and MIC+LIN settings are remembered separately in SSB and
DATA modes, so by using DATA A mode for FT8 you can avoid the need to
change settings back and forth as you change operating modes.

73,
Rich VE3KI