TV interference filter - RFI from HF-50MHz amateur radio station
Combination of symmetric High pass filter and common mode chokes. RFI filter will block common mode currents from HF - 50 MHz amateur radio station and filter all signals below 111 MHz "S2" wich is - lowest TV channel. All HF and 50MHz frequencies weakened 30 dB or more. It must be placed just before TV aerial socket.