Measuring the "FM band stop filter"

 

I quickly tested the MRDDZ BS "band-stop filter." The results weren't satisfactory:

                                        Measuring only the throughpass

                                             Marker 2: 150 MHz 

                   no 2m amateur radio - no AIR-band - no 136 WX satellites ...

                                88,5 MHz: -11,4 dB / 108 MHz: -21,4 dB