THANK YOU, haven't tried it yet, but I bet this is it
Page B-3
3. OUTPUT CONTROLS - The POWER MIG 300 has 2
encoder knobs to adjust weld parameters.
• Each encoder changes the displayed value of the meter
located directly above that encoder.
• In CC-GTAW modes, the left encoder sets the maximum
welding current. Full depression of a foot or hand
amptrol results in the preset level of current.
• In CC-Stick and CC-GTAW, the right encoder activates
and de-activates the output. Turning the encoder clockwise
enables the output if not using a remote trigger
device. To de-energize the output, turn the encoder
counter-clockwise. The display above will indicate the
"ON" or "OFF" status of the output.