Q.Provide instructions on how to measure impedance of a common mode filter / choke. EMV-Bauelemente >  EMV-Bauelemente >  Daten- und Signalleitungsdrosseln / Gleichtaktfilter A. Common mode /Z/ is measured by connecting the filter/choke coil as in Fig. 1. Differential mode /Z/ is measured by connecting the filter/choke coil as in Fig. 2. Fig.1.　Common mode /Z/ Fig.2.　Differential mode /Z/ product portal Common Mode Filters / Chokes Kontakt  Fragen zu Produkten, Vertrieb oder bei technischen Fragen