Technical GuidesHow to Choose Shielded vs Unshielded CablesKey Takeaways The 40 dB Rule: A correctly terminated foil-braid combination shield delivers 40–85 dB of EMI attenuation below 1 GHz; unshielded cable in the same environment may achieve less than 3 dB. Ground the Shield at One End Only… lcsccableJuly 22, 2026