Salary expectations: how do you answer? - what worked for you?

A recruiter asked for my salary expectations on a first call as I look for work as a machine operator. I have read a lot of threads here and could not find my exact situation. I looked up ranges in Madison and they vary a lot.

Thanks for writing this out. I went through something close to it last year, and it got easier once I kept a simple log of every call and form.