http://www.sss-mag.com/pdf/smithchart.pdf" [Broken], which scale at the bottom tells me the SWR? Is it the top line or the second line? (Among the 4 straight lines at the bottom of the chart) I'm confused because on the right and left of the line there are two different labels (SWR and ATTEN). Also, is the units of SWR in dBS? Thanks.