I can confirm that this knob is off when you cold start, and that it provide beeps boops and voice from the CMWS. Not yet familiar with the NAV mode.
CMWS/Nav Switch. Toggles ADF audio channel between CMWS threat reporting
when in CMWS mode, and ADF navaid audio when in NAV mode.
Set the master ARM mode on, the TPOD from SAFE to ARMED mode, and TRNL mode (training) to LSR (laser mode) then switch the tpod track mode with SENSOR Switch Down to "MT" mode (Moving Target), track mode will be displayed on the left down corner.