Attenuation for Coaxial and UTP Cables Posted on February 27, 2017 by Brandy McNeil Attenuation (dB/100 meters) Frequency (MHz) Thick Coax Thin Coax Cat. 3 UTP Cat. 4 UTP Cat.5 UTP 1 0.62 1.41 2.6 2.2 2.0 10 1.70 4.26 9.7 6.9 6.5 20 6.00 10.0 9.3 50 3.94 9.54 100 13.70 22.0 Note: UTP figures are based on TIA/EIA requirements for horizontal cable.