English: Ratio of G/ωC and R/ωL versus frequency for a typical RG-59 coaxial transmission line with a good (high resistivity), medium, and poor dielectric insulators. Near DC behavior is controlled by the series resistance of the conductors and the bulk resistivity of the dielectric, which has been taken to be approximately 10¹⁵ Ω-cm for the good dielectric in this example. The good dielectric is representative of modern high quality foam insulation. Gutta-percha is a medium dielectric and pulp is a poor dielectric. Generating equations are: C = a constant, ${\displaystyle C=C_{\infty },\,G=G_{dc}+\omega C\tan \delta ,\,L=L_{\infty }+\Delta L_{\omega }}$ with ${\displaystyle R{\text{ and }}\Delta L_{\omega }}$ computed from a formula by Weeks as described in skin effect.