The signal transmission characteristics of coaxial cables are generally calculated for the ideal concentric-cylinder-type cable as shown in the figure on the left. However, most coaxial cables have an inner conductor consisting of stranded wires and an outer conductor of braid or served shield, thus requiring the calculation to obtain effective outer diameters of both inner conductor and dielectric.
When inner or outer conductors are silver-plated or bare annealed copper
Correction for temperature (t℃) other than 20℃
Correction to be made when inner and outer conductors are tin-plated (Sn thickness 0.8μm) annealed copper
Correction to be made when inner conductor is copper-covered steel wire