The current flowing through the Yoke coil of the horizontal deflection resonates at higher frequencies of 150~200 times that of the saw tooth current due to the stray capacitance of the yoke coil. This produces ringing current in the Yoke coil which deterioates the picture on the CRT screen. One may reduce this ringing by adding a parallel circuit consisted of resistors, a capacitor, and a diode. The elements of this circuit are qualitatively calculated from the equivalent circuit of the Yoke coil which is derived from its measured impedance.
