The SY9223-120B balancing transformer / balun (English: balanced-unbalanced ) converts an unbalanced signal with 50 Ω source impedance into a galvanically isolated symmetrical signal with 120 Ω impedance over a large frequency range.
With conventional measuring devices, the system impedance of which is usually 50 Ω, measurements can be carried out on symmetrical four-pole systems, the impedance of which is 120 Ω.
For example, the transmission behavior of VDSL2 + lines can be determined in this way. Analogously, measurements according to CISPR 17 (or DIN EN 55017) can also be carried out on components or filters.