Which of the following conductors is preferred for bonding at RF?

At radio frequencies (RF), electrical current does not travel evenly through the entire cross-section of a wire. Because of a phenomenon known as the 'skin effect,' RF energy tends to travel almost entirely along the surface of the conductor. Therefore, to achieve low impedance at RF, a conductor needs a very large surface area. A flat copper strap is preferred for RF bonding because it provides a massive surface area relative to its thickness, minimizing RF impedance and preventing voltage differences between pieces of equipment in your station. While copper braid removed from coaxial cable might seem like a good idea because it is flat and flexible, it is a poor choice. Braid can act like a sponge for moisture, leading to rapid corrosion, and the friction between individual strands can generate RF noise when the braid is flexed. Steel wire and twisted-pair cable have high impedance at RF and are unsuitable for bonding.