Physical Dimensions Component Standard Shield Inches        mm Tri-Shield Inches         mm Super-Shield Inches         mm Nominal Center Conductor Diameter 0.064 1.63 0.064 1.63 0.064 1.63 Nominal Diameter Over Dielectric 0.280 7.11 0.280 7.11 0.280 7.11 Nominal Diameter Over First Shield(Tape) 0.287 7.29 0.287 7.29 0.287 7.29 Nominal Diameter Over Jacket 0.395 10.03 0.395 10.03 0.405 10.29 Nominal Jacket Wall Thickness 0.042 1.07 0.039 0.99 0.037 0.94 Nominal Diameter of Steel Messenger 0.051(single) 1.83 0.051(single) 1.83 0.051(single) 1.83 0.072(dual) 2.77 0.072(dual) 2.77 0.072(dual) 2.77 Electrical Characteristics Nominal Impedance 75 Ohms Nominal Velocity of Propogation 85% Attenuation [@68°F.(20℃.)] Frequency (MHz) Maximum (dB/100 ft) Maximum (dB/100 m) 5 0.38 1.25 55 0.96 0.96 88 1.18 3.87 187 1.75 5.74 211 1.9 6.23 250 2.05 7 300 2.25 7.38 350 2.42 7.94 400 2.6 8.53 450 2.75 9.02 500 2.9 9.51 550 3.04 9.97 600 3.18 10.43 750 3.65 11.97 865 3.98 13.05 1000 4.35 14.27