Row line with magnetic ring, row line magnetic ring, dang interference signal band more wide Shi, can in cable put two a magnetic ring, each magnetic around different of turns number, such can while a high frequency interference and low frequency interference. is not impedance more big, on interference signal of inhibit effect more good, because actual magnetic ring Shang exists parasitic capacitor, this parasitic capacitor and inductance parallel, but encountered high frequency interference signal Shi, this parasitic capacitor will magnetic ring of inductance short-circuit, lost role.