hi i am a roolie welder and i want to get a ac tig machine but i want to be shure to get squarewave cause everyone ive talked to said its way better and i want to know if this l tec i have a chance to buy is a squarewave machine or not someone please help i would apprecieate it a great deal im not going to by it if its not and any guesses to its age w help the owqner doesnt know too much about it