CHAPTER 6 Transmission Techniques: Wire and Cable 10,000 9000 8000 7000 6000 5000 4000 3000 2000 1000 0 1 Zin k 10 f k 100 1000 FIGURE 6.15 Effect of a telescopic ground on a Cat 6 cable. shows the input impedance, the impedance presented to any RF traveling on the shield, at frequency F k (bottom scale) in MHz. You will note that at every half-wavelength, the shield acts like an open circuit. Since most audio cables