Circuit arrangement for pilot separation

摘要

In a circuit arrangement for separation of a pilot signal from a transmission band and for blocking the pilot signal in the useful signal of the transmission band, a hybrid circuit is provided, on one hybrid arm of which a narrowband filter tuned to the pilot frequency is disposed. In order to avoid the need for a pilot blocking filter, the narrowband filter has a frequency-dependent input impedance which has an approximately real active resistance at the pilot frequency but has a reactance which differs substantially from it at other frequencies of the transmission band. A simulation of the above-mentioned active resistance is disposed in the second hybrid arm. The useful signal of the transmission band is tapped at the hybrid shunt arm.