I'm a new owner of a Shreman 206p. Liking it a lot thus far - only previous experience of TIG and aluminium was a local class about 8 years ago andgot very little TIG time. Thus far I have used without the foot pedal but began to feel I was getting too many amps towards the end of a run so tried the pedal. Can someone knowledgeable tell me what the pot on the side of the Sherman pedal controls? In my naivety I thought that once the max amps were set on the Sherman the pedal gave full whack when fully depressed and amps decreased as one backed of the pedal. The pot confuses me as can't see what it does! Also, in passing, the pedal seems to be pretty on/off - how have others found it?